3.2.0 Big revamp

frontends/api/API_UPDATE_SUMMARY_V3.2.0.md

@@ -0,0 +1,500 @@
+# API Update Summary for v3.2.0
+
+## Overview
+
+The FastAPI REST API has been updated to align with Stegasoo v3.2.0's breaking changes:
+1. **Removed date dependency** - No `date_str` field in requests
+2. **Renamed day_phrase → passphrase** - Updated all request/response models
+3. **Updated generation** - Now generates single passphrase instead of daily phrases
+
+## Breaking Changes
+
+### Request Model Changes
+
+#### 1. EncodeRequest & EncodeFileRequest
+
+**Before (v3.1.0):**
+```python
+class EncodeRequest(BaseModel):
+    message: str
+    reference_photo_base64: str
+    carrier_image_base64: str
+    day_phrase: str  # ← Changed to passphrase
+    pin: str = ""
+    rsa_key_base64: Optional[str] = None
+    rsa_password: Optional[str] = None
+    date_str: Optional[str] = None  # ← REMOVED
+    embed_mode: EmbedModeType = "lsb"
+```
+
+**After (v3.2.0):**
+```python
+class EncodeRequest(BaseModel):
+    message: str
+    reference_photo_base64: str
+    carrier_image_base64: str
+    passphrase: str = Field(description="Passphrase (v3.2.0: renamed from day_phrase)")
+    pin: str = ""
+    rsa_key_base64: Optional[str] = None
+    rsa_password: Optional[str] = None
+    # date_str removed in v3.2.0
+    embed_mode: EmbedModeType = "lsb"
+    dct_output_format: DctOutputFormatType = "png"
+    dct_color_mode: DctColorModeType = "grayscale"
+```
+
+#### 2. DecodeRequest
+
+**Before (v3.1.0):**
+```python
+class DecodeRequest(BaseModel):
+    stego_image_base64: str
+    reference_photo_base64: str
+    day_phrase: str  # ← Changed to passphrase
+    pin: str = ""
+    rsa_key_base64: Optional[str] = None
+    rsa_password: Optional[str] = None
+    embed_mode: ExtractModeType = "auto"
+```
+
+**After (v3.2.0):**
+```python
+class DecodeRequest(BaseModel):
+    stego_image_base64: str
+    reference_photo_base64: str
+    passphrase: str = Field(description="Passphrase (v3.2.0: renamed from day_phrase)")
+    pin: str = ""
+    rsa_key_base64: Optional[str] = None
+    rsa_password: Optional[str] = None
+    embed_mode: ExtractModeType = "auto"
+```
+
+#### 3. GenerateRequest
+
+**Before (v3.1.0):**
+```python
+class GenerateRequest(BaseModel):
+    use_pin: bool = True
+    use_rsa: bool = False
+    pin_length: int = Field(default=6, ge=MIN_PIN_LENGTH, le=MAX_PIN_LENGTH)
+    rsa_bits: int = Field(default=2048)
+    words_per_phrase: int = Field(default=3, ge=MIN_PHRASE_WORDS, le=MAX_PHRASE_WORDS)
+```
+
+**After (v3.2.0):**
+```python
+class GenerateRequest(BaseModel):
+    use_pin: bool = True
+    use_rsa: bool = False
+    pin_length: int = Field(default=6, ge=MIN_PIN_LENGTH, le=MAX_PIN_LENGTH)
+    rsa_bits: int = Field(default=2048)
+    words_per_passphrase: int = Field(
+        default=DEFAULT_PASSPHRASE_WORDS,  # = 4, was 3
+        ge=MIN_PASSPHRASE_WORDS,
+        le=MAX_PASSPHRASE_WORDS,
+        description="Words per passphrase (v3.2.0: default increased to 4)"
+    )
+```
+
+### Response Model Changes
+
+#### 1. GenerateResponse
+
+**Before (v3.1.0):**
+```python
+class GenerateResponse(BaseModel):
+    phrases: dict[str, str]  # Monday -> phrase, Tuesday -> phrase, etc.
+    pin: Optional[str] = None
+    rsa_key_pem: Optional[str] = None
+    entropy: dict[str, int]
+```
+
+**After (v3.2.0):**
+```python
+class GenerateResponse(BaseModel):
+    passphrase: str = Field(description="Single passphrase (v3.2.0: no daily rotation)")
+    pin: Optional[str] = None
+    rsa_key_pem: Optional[str] = None
+    entropy: dict[str, int]
+    # Legacy field for compatibility
+    phrases: Optional[dict[str, str]] = Field(
+        default=None,
+        description="Deprecated: Use 'passphrase' instead"
+    )
+```
+
+#### 2. EncodeResponse
+
+**Before (v3.1.0):**
+```python
+class EncodeResponse(BaseModel):
+    stego_image_base64: str
+    filename: str
+    capacity_used_percent: float
+    date_used: str
+    day_of_week: str
+    embed_mode: str
+    output_format: str = "png"
+    color_mode: str = "color"
+```
+
+**After (v3.2.0):**
+```python
+class EncodeResponse(BaseModel):
+    stego_image_base64: str
+    filename: str
+    capacity_used_percent: float
+    embed_mode: str
+    output_format: str = "png"
+    color_mode: str = "color"
+    # Legacy fields (no longer used in crypto)
+    date_used: Optional[str] = Field(
+        default=None,
+        description="Deprecated: Date no longer used in v3.2.0"
+    )
+    day_of_week: Optional[str] = Field(
+        default=None,
+        description="Deprecated: Date no longer used in v3.2.0"
+    )
+```
+
+### Endpoint Changes
+
+#### 1. POST /encode
+
+**Before (v3.1.0):**
+```json
+{
+  "message": "Secret message",
+  "reference_photo_base64": "...",
+  "carrier_image_base64": "...",
+  "day_phrase": "apple forest thunder",
+  "date_str": "2025-01-15",
+  "pin": "123456",
+  "embed_mode": "lsb"
+}
+```
+
+**After (v3.2.0):**
+```json
+{
+  "message": "Secret message",
+  "reference_photo_base64": "...",
+  "carrier_image_base64": "...",
+  "passphrase": "apple forest thunder mountain",
+  "pin": "123456",
+  "embed_mode": "lsb"
+}
+```
+
+#### 2. POST /decode
+
+**Before (v3.1.0):**
+```json
+{
+  "stego_image_base64": "...",
+  "reference_photo_base64": "...",
+  "day_phrase": "apple forest thunder",
+  "pin": "123456",
+  "embed_mode": "auto"
+}
+```
+
+**After (v3.2.0):**
+```json
+{
+  "stego_image_base64": "...",
+  "reference_photo_base64": "...",
+  "passphrase": "apple forest thunder mountain",
+  "pin": "123456",
+  "embed_mode": "auto"
+}
+```
+
+#### 3. POST /generate
+
+**Response Before (v3.1.0):**
+```json
+{
+  "phrases": {
+    "Monday": "apple forest thunder",
+    "Tuesday": "banana river lightning",
+    ...
+  },
+  "pin": "123456",
+  "rsa_key_pem": null,
+  "entropy": {
+    "phrase": 33,
+    "pin": 20,
+    "rsa": 0,
+    "total": 53
+  }
+}
+```
+
+**Response After (v3.2.0):**
+```json
+{
+  "passphrase": "apple forest thunder mountain",
+  "pin": "123456",
+  "rsa_key_pem": null,
+  "entropy": {
+    "passphrase": 44,
+    "pin": 20,
+    "rsa": 0,
+    "total": 64
+  },
+  "phrases": null
+}
+```
+
+#### 4. POST /encode/multipart
+
+**Form Fields Before (v3.1.0):**
+- `day_phrase` (required)
+- `date_str` (optional)
+- `reference_photo` (file)
+- `carrier` (file)
+- ...
+
+**Form Fields After (v3.2.0):**
+- `passphrase` (required) ← renamed from day_phrase
+- `reference_photo` (file)
+- `carrier` (file)
+- ... (date_str removed)
+
+**Response Headers Before (v3.1.0):**
+```
+X-Stegasoo-Date: 2025-01-15
+X-Stegasoo-Day: Wednesday
+X-Stegasoo-Capacity-Percent: 25.5
+X-Stegasoo-Embed-Mode: lsb
+```
+
+**Response Headers After (v3.2.0):**
+```
+X-Stegasoo-Capacity-Percent: 25.5
+X-Stegasoo-Embed-Mode: lsb
+X-Stegasoo-Output-Format: png
+X-Stegasoo-Color-Mode: color
+X-Stegasoo-Version: 3.2.0
+```
+
+### New Status Endpoint Information
+
+#### GET /
+
+**Added to response:**
+```json
+{
+  "version": "3.2.0",
+  ...
+  "breaking_changes": {
+    "date_removed": "No date_str parameter needed - encode/decode anytime",
+    "passphrase_renamed": "day_phrase → passphrase (single passphrase, no daily rotation)",
+    "format_version": 4,
+    "backward_compatible": false
+  }
+}
+```
+
+## Migration Guide for API Clients
+
+### 1. Update Request Bodies
+
+**Find and replace in client code:**
+```javascript
+// Before
+{
+  day_phrase: "apple forest thunder",
+  date_str: "2025-01-15"
+}
+
+// After
+{
+  passphrase: "apple forest thunder mountain"
+}
+```
+
+### 2. Update Response Handling
+
+**Before:**
+```javascript
+const response = await fetch('/encode', {
+  method: 'POST',
+  body: JSON.stringify({
+    message: "secret",
+    day_phrase: "words",
+    date_str: "2025-01-15",
+    ...
+  })
+});
+
+const data = await response.json();
+console.log(data.date_used);  // "2025-01-15"
+console.log(data.day_of_week);  // "Wednesday"
+```
+
+**After:**
+```javascript
+const response = await fetch('/encode', {
+  method: 'POST',
+  body: JSON.stringify({
+    message: "secret",
+    passphrase: "longer words here now",
+    // date_str removed
+    ...
+  })
+});
+
+const data = await response.json();
+// date_used and day_of_week are null in v3.2.0
+```
+
+### 3. Update Generate Endpoint Usage
+
+**Before:**
+```javascript
+const creds = await fetch('/generate', {
+  method: 'POST',
+  body: JSON.stringify({ use_pin: true })
+}).then(r => r.json());
+
+// Use Monday's phrase
+const mondayPhrase = creds.phrases['Monday'];
+```
+
+**After:**
+```javascript
+const creds = await fetch('/generate', {
+  method: 'POST',
+  body: JSON.stringify({ use_pin: true })
+}).then(r => r.json());
+
+// Use single passphrase
+const passphrase = creds.passphrase;
+```
+
+### 4. Update Multipart Requests
+
+**Before (JavaScript fetch):**
+```javascript
+const formData = new FormData();
+formData.append('day_phrase', 'apple forest thunder');
+formData.append('date_str', '2025-01-15');
+formData.append('reference_photo', refPhotoFile);
+formData.append('carrier', carrierFile);
+formData.append('message', 'secret');
+formData.append('pin', '123456');
+
+const response = await fetch('/encode/multipart', {
+  method: 'POST',
+  body: formData
+});
+```
+
+**After (JavaScript fetch):**
+```javascript
+const formData = new FormData();
+formData.append('passphrase', 'apple forest thunder mountain');
+// date_str removed
+formData.append('reference_photo', refPhotoFile);
+formData.append('carrier', carrierFile);
+formData.append('message', 'secret');
+formData.append('pin', '123456');
+
+const response = await fetch('/encode/multipart', {
+  method: 'POST',
+  body: formData
+});
+```
+
+## Testing Checklist
+
+### Endpoints to Test
+
+- [ ] GET / - Returns v3.2.0 with breaking_changes info
+- [ ] GET /modes - Returns mode information
+- [ ] POST /generate - Returns single passphrase
+- [ ] POST /encode - Works without date_str
+- [ ] POST /encode/file - Works without date_str
+- [ ] POST /decode - Works without date_str
+- [ ] POST /encode/multipart - Accepts passphrase instead of day_phrase
+- [ ] POST /decode/multipart - Accepts passphrase instead of day_phrase
+- [ ] POST /compare - Still works
+- [ ] POST /will-fit - Still works
+- [ ] POST /image/info - Still works
+- [ ] POST /extract-key-from-qr - Still works
+
+### Validation Tests
+
+- [ ] Reject requests with `day_phrase` field (should get validation error)
+- [ ] Reject requests with `date_str` field (should be ignored or error)
+- [ ] Accept requests with `passphrase` field
+- [ ] Generate response includes `passphrase` field
+- [ ] Generate response has `phrases` as null
+- [ ] Encode response has `date_used` and `day_of_week` as null
+- [ ] Multipart encode works with new field names
+- [ ] Response headers updated correctly
+
+## OpenAPI/Swagger Documentation
+
+The FastAPI auto-generated documentation (/docs and /redoc) will automatically reflect the changes:
+
+1. **Models updated** - Request/response schemas show new field names
+2. **Descriptions updated** - Field descriptions mention v3.2.0 changes
+3. **Examples updated** - Interactive API explorer uses new field names
+
+Users can browse to `/docs` to see the updated API specification.
+
+## Backward Compatibility
+
+**Breaking Change:** API v3.2.0 is NOT backward compatible with v3.1.0
+
+Clients using the old API will encounter:
+1. **Validation errors** - Missing required `passphrase` field
+2. **Unexpected responses** - `phrases` field will be null
+3. **Changed behavior** - Date fields no longer populated
+
+### Migration Timeline Recommendation
+
+1. **Deploy v3.2.0 API** to staging
+2. **Update client applications** to use new field names
+3. **Test thoroughly** with staging API
+4. **Deploy v3.2.0 API** to production
+5. **Notify users** of breaking changes
+
+Alternatively, run v3.1.0 and v3.2.0 APIs side-by-side on different paths:
+- `/api/v3.1/` - Old API
+- `/api/v3.2/` - New API
+
+## Constants Updates
+
+Used in validation:
+```python
+from stegasoo.constants import (
+    MIN_PASSPHRASE_WORDS,  # = 3
+    MAX_PASSPHRASE_WORDS,  # = 12
+    DEFAULT_PASSPHRASE_WORDS,  # = 4 (increased from 3)
+)
+```
+
+## Error Messages
+
+All error messages updated:
+- "day_phrase is required" → "passphrase is required"
+- References to "phrase" now mean "passphrase"
+
+## Implementation Status
+
+✅ All request models updated
+✅ All response models updated
+✅ All endpoints updated
+✅ Multipart endpoints updated
+✅ Status endpoint shows breaking changes
+✅ Constants imported correctly
+✅ Error handling updated
+✅ No references to day_phrase in user-facing text
+✅ No date_str parameters accepted
+
+Ready for deployment!

frontends/api/main.py

@@ -1,9 +1,16 @@
 #!/usr/bin/env python3
 """
-Stegasoo REST API (v3.0.1)
+Stegasoo REST API (v3.2.0)
 
 FastAPI-based REST API for steganography operations.
 Supports both text messages and file embedding.
+
+CHANGES in v3.2.0:
+- Removed date dependency from all operations
+- Renamed day_phrase → passphrase
+- No date_str parameters needed
+- Simplified API for asynchronous communications
+
 NEW in v3.0: LSB and DCT embedding modes.
 NEW in v3.0.1: DCT color mode and JPEG output format.
 """
@@ -26,13 +33,12 @@ import stegasoo
 from stegasoo import (
     encode, decode, generate_credentials,
     validate_image, calculate_capacity,
-    get_day_from_date,
+    __version__,
-    DAY_NAMES, __version__,
     StegasooError, DecryptionError, CapacityError,
     has_argon2,
     FilePayload,
     MAX_FILE_PAYLOAD_SIZE,
-    # NEW in v3.0 - Embedding modes
+    # Embedding modes
     EMBED_MODE_LSB,
     EMBED_MODE_DCT,
     EMBED_MODE_AUTO,
@@ -43,7 +49,8 @@ from stegasoo import (
 )
 from stegasoo.constants import (
     MIN_PIN_LENGTH, MAX_PIN_LENGTH,
-    MIN_PHRASE_WORDS, MAX_PHRASE_WORDS,
+    MIN_PASSPHRASE_WORDS, MAX_PASSPHRASE_WORDS,
+    DEFAULT_PASSPHRASE_WORDS,
     VALID_RSA_SIZES,
 )
 
@@ -68,6 +75,12 @@ app = FastAPI(
     description="""
 Secure steganography with hybrid authentication. Supports text messages and file embedding.
 
+## Version 3.2.0 Changes
+
+- **No date parameters needed** - Encode and decode anytime without tracking dates
+- **Single passphrase** - No daily rotation, just use your passphrase
+- **True asynchronous communications** - Perfect for dead drops and delayed delivery
+
 ## Embedding Modes (v3.0)
 
 - **LSB mode** (default): Spatial LSB embedding, full color output, higher capacity
@@ -105,25 +118,35 @@ class GenerateRequest(BaseModel):
     use_rsa: bool = False
     pin_length: int = Field(default=6, ge=MIN_PIN_LENGTH, le=MAX_PIN_LENGTH)
     rsa_bits: int = Field(default=2048)
-    words_per_phrase: int = Field(default=3, ge=MIN_PHRASE_WORDS, le=MAX_PHRASE_WORDS)
+    words_per_passphrase: int = Field(
+        default=DEFAULT_PASSPHRASE_WORDS,
+        ge=MIN_PASSPHRASE_WORDS,
+        le=MAX_PASSPHRASE_WORDS,
+        description="Words per passphrase (v3.2.0: default increased to 4)"
+    )
 
 
 class GenerateResponse(BaseModel):
-    phrases: dict[str, str]
+    passphrase: str = Field(description="Single passphrase (v3.2.0: no daily rotation)")
     pin: Optional[str] = None
     rsa_key_pem: Optional[str] = None
     entropy: dict[str, int]
+    # Legacy field for compatibility
+    phrases: Optional[dict[str, str]] = Field(
+        default=None,
+        description="Deprecated: Use 'passphrase' instead"
+    )
 
 
 class EncodeRequest(BaseModel):
     message: str
     reference_photo_base64: str
     carrier_image_base64: str
-    day_phrase: str
+    passphrase: str = Field(description="Passphrase (v3.2.0: renamed from day_phrase)")
     pin: str = ""
     rsa_key_base64: Optional[str] = None
     rsa_password: Optional[str] = None
-    date_str: Optional[str] = None
+    # date_str removed in v3.2.0
     embed_mode: EmbedModeType = Field(
         default="lsb",
         description="Embedding mode: 'lsb' (default, color) or 'dct' (requires scipy)"
@@ -146,11 +169,11 @@ class EncodeFileRequest(BaseModel):
     mime_type: Optional[str] = None
     reference_photo_base64: str
     carrier_image_base64: str
-    day_phrase: str
+    passphrase: str = Field(description="Passphrase (v3.2.0: renamed from day_phrase)")
     pin: str = ""
     rsa_key_base64: Optional[str] = None
     rsa_password: Optional[str] = None
-    date_str: Optional[str] = None
+    # date_str removed in v3.2.0
     embed_mode: EmbedModeType = Field(
         default="lsb",
         description="Embedding mode: 'lsb' (default, color) or 'dct' (requires scipy)"
@@ -170,8 +193,6 @@ class EncodeResponse(BaseModel):
     stego_image_base64: str
     filename: str
     capacity_used_percent: float
-    date_used: str
-    day_of_week: str
     embed_mode: str = Field(description="Embedding mode used: 'lsb' or 'dct'")
     # NEW in v3.0.1
     output_format: str = Field(
@@ -182,12 +203,21 @@ class EncodeResponse(BaseModel):
         default="color",
         description="Color mode: 'color' (LSB/DCT color) or 'grayscale' (DCT grayscale)"
     )
+    # Legacy fields (v3.2.0: no longer used in crypto)
+    date_used: Optional[str] = Field(
+        default=None,
+        description="Deprecated: Date no longer used in v3.2.0"
+    )
+    day_of_week: Optional[str] = Field(
+        default=None,
+        description="Deprecated: Date no longer used in v3.2.0"
+    )
 
 
 class DecodeRequest(BaseModel):
     stego_image_base64: str
     reference_photo_base64: str
-    day_phrase: str
+    passphrase: str = Field(description="Passphrase (v3.2.0: renamed from day_phrase)")
     pin: str = ""
     rsa_key_base64: Optional[str] = None
     rsa_password: Optional[str] = None
@@ -268,7 +298,6 @@ class StatusResponse(BaseModel):
     has_argon2: bool
     has_qrcode_read: bool
     has_dct: bool
-    day_names: list[str]
     max_payload_kb: int
     available_modes: list[str]
     # NEW in v3.0.1
@@ -276,6 +305,10 @@ class StatusResponse(BaseModel):
         default=None,
         description="DCT mode features (v3.0.1+)"
     )
+    # NEW in v3.2.0
+    breaking_changes: dict = Field(
+        description="v3.2.0 breaking changes"
+    )
 
 
 class QrExtractResponse(BaseModel):
@@ -330,10 +363,15 @@ async def root():
         has_argon2=has_argon2(),
         has_qrcode_read=HAS_QR_READ,
         has_dct=has_dct_support(),
-        day_names=list(DAY_NAMES),
         max_payload_kb=MAX_FILE_PAYLOAD_SIZE // 1024,
         available_modes=available_modes,
         dct_features=dct_features,
+        breaking_changes={
+            "date_removed": "No date_str parameter needed - encode/decode anytime",
+            "passphrase_renamed": "day_phrase → passphrase (single passphrase, no daily rotation)",
+            "format_version": 4,
+            "backward_compatible": False,
+        }
     )
 
 
@@ -496,6 +534,9 @@ async def api_generate(request: GenerateRequest):
     Generate credentials for encoding/decoding.
     
     At least one of use_pin or use_rsa must be True.
+    
+    v3.2.0: Generates single passphrase (no daily rotation).
+    Default increased to 4 words for better security.
     """
     if not request.use_pin and not request.use_rsa:
         raise HTTPException(400, "Must enable at least one of use_pin or use_rsa")
@@ -509,19 +550,20 @@ async def api_generate(request: GenerateRequest):
             use_rsa=request.use_rsa,
             pin_length=request.pin_length,
             rsa_bits=request.rsa_bits,
-            words_per_phrase=request.words_per_phrase
+            words_per_passphrase=request.words_per_passphrase
         )
         
         return GenerateResponse(
-            phrases=creds.phrases,
+            passphrase=creds.passphrase,  # v3.2.0: Single passphrase
             pin=creds.pin,
             rsa_key_pem=creds.rsa_key_pem,
             entropy={
-                "phrase": creds.phrase_entropy,
+                "passphrase": creds.passphrase_entropy,
                 "pin": creds.pin_entropy,
                 "rsa": creds.rsa_entropy,
                 "total": creds.total_entropy
-            }
+            },
+            phrases=None  # Legacy field removed
         )
     except Exception as e:
         raise HTTPException(500, str(e))
@@ -573,6 +615,8 @@ async def api_encode(request: EncodeRequest):
     
     Images must be base64-encoded. Returns base64-encoded stego image.
     
+    v3.2.0: No date_str parameter needed - encode anytime!
+    
     NEW in v3.0: Supports embed_mode parameter ('lsb' or 'dct').
     NEW in v3.0.1: Supports dct_output_format ('png' or 'jpeg') and dct_color_mode ('grayscale' or 'color').
     """
@@ -592,21 +636,21 @@ async def api_encode(request: EncodeRequest):
             request.dct_color_mode
         )
         
+        # v3.2.0: No date_str parameter
         result = encode(
             message=request.message,
             reference_photo=ref_photo,
             carrier_image=carrier,
-            day_phrase=request.day_phrase,
+            passphrase=request.passphrase,  # v3.2.0: Renamed from day_phrase
             pin=request.pin,
             rsa_key_data=rsa_key,
             rsa_password=request.rsa_password,
-            date_str=request.date_str,
+            # date_str removed in v3.2.0
             embed_mode=request.embed_mode,
-            **dct_params,  # NEW in v3.0.1
+            **dct_params,
         )
         
         stego_b64 = base64.b64encode(result.stego_image).decode('utf-8')
-        day_of_week = get_day_from_date(result.date_used)
         
         output_format, color_mode, _ = _get_output_info(
             request.embed_mode,
@@ -618,11 +662,11 @@ async def api_encode(request: EncodeRequest):
             stego_image_base64=stego_b64,
             filename=result.filename,
             capacity_used_percent=result.capacity_percent,
-            date_used=result.date_used,
-            day_of_week=day_of_week,
             embed_mode=request.embed_mode,
             output_format=output_format,
             color_mode=color_mode,
+            date_used=None,  # v3.2.0: No longer used
+            day_of_week=None,  # v3.2.0: No longer used
         )
         
     except CapacityError as e:
@@ -640,6 +684,8 @@ async def api_encode_file(request: EncodeFileRequest):
     
     File data must be base64-encoded.
     
+    v3.2.0: No date_str parameter needed - encode anytime!
+    
     NEW in v3.0: Supports embed_mode parameter ('lsb' or 'dct').
     NEW in v3.0.1: Supports dct_output_format and dct_color_mode.
     """
@@ -666,21 +712,21 @@ async def api_encode_file(request: EncodeFileRequest):
             request.dct_color_mode
         )
         
+        # v3.2.0: No date_str parameter
         result = encode(
             message=payload,
             reference_photo=ref_photo,
             carrier_image=carrier,
-            day_phrase=request.day_phrase,
+            passphrase=request.passphrase,  # v3.2.0: Renamed from day_phrase
             pin=request.pin,
             rsa_key_data=rsa_key,
             rsa_password=request.rsa_password,
-            date_str=request.date_str,
+            # date_str removed in v3.2.0
             embed_mode=request.embed_mode,
-            **dct_params,  # NEW in v3.0.1
+            **dct_params,
         )
         
         stego_b64 = base64.b64encode(result.stego_image).decode('utf-8')
-        day_of_week = get_day_from_date(result.date_used)
         
         output_format, color_mode, _ = _get_output_info(
             request.embed_mode,
@@ -692,11 +738,11 @@ async def api_encode_file(request: EncodeFileRequest):
             stego_image_base64=stego_b64,
             filename=result.filename,
             capacity_used_percent=result.capacity_percent,
-            date_used=result.date_used,
-            day_of_week=day_of_week,
             embed_mode=request.embed_mode,
             output_format=output_format,
             color_mode=color_mode,
+            date_used=None,  # v3.2.0: No longer used
+            day_of_week=None,  # v3.2.0: No longer used
         )
         
     except CapacityError as e:
@@ -718,6 +764,8 @@ async def api_decode(request: DecodeRequest):
     
     Returns payload_type to indicate if result is text or file.
     
+    v3.2.0: No date_str parameter needed - decode anytime!
+    
     NEW in v3.0: Supports embed_mode parameter ('auto', 'lsb', or 'dct').
     With 'auto' (default), tries LSB first then DCT.
     
@@ -733,10 +781,11 @@ async def api_decode(request: DecodeRequest):
         ref_photo = base64.b64decode(request.reference_photo_base64)
         rsa_key = base64.b64decode(request.rsa_key_base64) if request.rsa_key_base64 else None
         
+        # v3.2.0: No date_str parameter
         result = decode(
             stego_image=stego,
             reference_photo=ref_photo,
-            day_phrase=request.day_phrase,
+            passphrase=request.passphrase,  # v3.2.0: Renamed from day_phrase
             pin=request.pin,
             rsa_key_data=rsa_key,
             rsa_password=request.rsa_password,
@@ -770,7 +819,7 @@ async def api_decode(request: DecodeRequest):
 
 @app.post("/encode/multipart")
 async def api_encode_multipart(
-    day_phrase: str = Form(...),
+    passphrase: str = Form(..., description="Passphrase (v3.2.0: renamed from day_phrase)"),
     reference_photo: UploadFile = File(...),
     carrier: UploadFile = File(...),
     message: str = Form(""),
@@ -779,7 +828,7 @@ async def api_encode_multipart(
     rsa_key: Optional[UploadFile] = File(None),
     rsa_key_qr: Optional[UploadFile] = File(None),
     rsa_password: str = Form(""),
-    date_str: str = Form(""),
+    # date_str removed in v3.2.0
     embed_mode: str = Form("lsb"),
     # NEW in v3.0.1
     dct_output_format: str = Form("png"),
@@ -792,6 +841,8 @@ async def api_encode_multipart(
     RSA key can be provided as 'rsa_key' (.pem file) or 'rsa_key_qr' (QR code image).
     Returns the stego image directly with metadata headers.
     
+    v3.2.0: No date_str parameter needed - encode anytime!
+    
     NEW in v3.0: Supports embed_mode parameter ('lsb' or 'dct').
     NEW in v3.0.1: Supports dct_output_format ('png' or 'jpeg') and dct_color_mode ('grayscale' or 'color').
     """
@@ -849,20 +900,20 @@ async def api_encode_multipart(
         # Get DCT parameters
         dct_params = _get_dct_params(embed_mode, dct_output_format, dct_color_mode)
         
+        # v3.2.0: No date_str parameter
         result = encode(
             message=payload,
             reference_photo=ref_data,
             carrier_image=carrier_data,
-            day_phrase=day_phrase,
+            passphrase=passphrase,  # v3.2.0: Renamed from day_phrase
             pin=pin,
             rsa_key_data=rsa_key_data,
             rsa_password=effective_password,
-            date_str=date_str if date_str else None,
+            # date_str removed in v3.2.0
             embed_mode=embed_mode,
-            **dct_params,  # NEW in v3.0.1
+            **dct_params,
         )
         
-        day_of_week = get_day_from_date(result.date_used)
         output_format, color_mode, mime_type = _get_output_info(
             embed_mode, dct_output_format, dct_color_mode
         )
@@ -872,12 +923,11 @@ async def api_encode_multipart(
             media_type=mime_type,
             headers={
                 "Content-Disposition": f"attachment; filename={result.filename}",
-                "X-Stegasoo-Date": result.date_used,
-                "X-Stegasoo-Day": day_of_week,
                 "X-Stegasoo-Capacity-Percent": f"{result.capacity_percent:.1f}",
                 "X-Stegasoo-Embed-Mode": embed_mode,
-                "X-Stegasoo-Output-Format": output_format,  # NEW in v3.0.1
+                "X-Stegasoo-Output-Format": output_format,
-                "X-Stegasoo-Color-Mode": color_mode,  # NEW in v3.0.1
+                "X-Stegasoo-Color-Mode": color_mode,
+                "X-Stegasoo-Version": __version__,
             }
         )
         
@@ -893,7 +943,7 @@ async def api_encode_multipart(
 
 @app.post("/decode/multipart", response_model=DecodeResponse)
 async def api_decode_multipart(
-    day_phrase: str = Form(...),
+    passphrase: str = Form(..., description="Passphrase (v3.2.0: renamed from day_phrase)"),
     reference_photo: UploadFile = File(...),
     stego_image: UploadFile = File(...),
     pin: str = Form(""),
@@ -908,6 +958,8 @@ async def api_decode_multipart(
     RSA key can be provided as 'rsa_key' (.pem file) or 'rsa_key_qr' (QR code image).
     Returns JSON with payload_type indicating text or file.
     
+    v3.2.0: No date_str parameter needed - decode anytime!
+    
     NEW in v3.0: Supports embed_mode parameter ('auto', 'lsb', or 'dct').
     
     Note: Extraction works the same regardless of color mode used during encoding.
@@ -944,10 +996,11 @@ async def api_decode_multipart(
         # QR code keys are never password-protected
         effective_password = None if rsa_key_from_qr else (rsa_password if rsa_password else None)
         
+        # v3.2.0: No date_str parameter
         result = decode(
             stego_image=stego_data,
             reference_photo=ref_data,
-            day_phrase=day_phrase,
+            passphrase=passphrase,  # v3.2.0: Renamed from day_phrase
             pin=pin,
             rsa_key_data=rsa_key_data,
             rsa_password=effective_password,
@@ -1022,7 +1075,7 @@ async def api_image_info(
                     capacity_bytes=comparison['dct']['capacity_bytes'],
                     capacity_kb=round(comparison['dct']['capacity_kb'], 1),
                     available=comparison['dct']['available'],
-                    output_format="PNG/JPEG (grayscale or color)",  # Updated for v3.0.1
+                    output_format="PNG/JPEG (grayscale or color)",
                 ),
             }
         

frontends/cli/main.py

@@ -1,6 +1,11 @@
 #!/usr/bin/env python3
 """
-Stegasoo CLI - Command-line interface for steganography operations (v3.0.1).
+Stegasoo CLI - Command-line interface for steganography operations (v3.2.0).
+
+CHANGES in v3.2.0:
+- Removed date dependency from all operations
+- Renamed day_phrase → passphrase
+- No longer need to specify or remember encoding dates
 
 Usage:
     stegasoo generate [OPTIONS]
@@ -10,10 +15,6 @@ Usage:
     stegasoo info [OPTIONS]
     stegasoo compare [OPTIONS]
     stegasoo modes [OPTIONS]
-
-New in v3.0.1:
-    - DCT color mode: --dct-color (grayscale or color)
-    - DCT output format: --dct-format (png or jpeg)
 """
 
 import sys
@@ -31,13 +32,13 @@ from stegasoo import (
     generate_credentials,
     export_rsa_key_pem, load_rsa_key,
     validate_image, calculate_capacity,
-    get_day_from_date, parse_date_from_filename,
+    parse_date_from_filename,  # Keep for filename parsing only
-    DAY_NAMES, __version__,
+    __version__,
     StegasooError, DecryptionError, ExtractionError,
     FilePayload,
     will_fit,
     strip_image_metadata,
-    # NEW in v3.0 - Embedding modes
+    # Embedding modes
     EMBED_MODE_LSB,
     EMBED_MODE_DCT,
     EMBED_MODE_AUTO,
@@ -79,16 +80,22 @@ def cli():
     
     \b
     - Reference photo (something you have)
-    - Daily passphrase (something you know)
+    - Passphrase (something you know)
     - Static PIN or RSA key (additional security)
     
     \b
-    Embedding Modes (v3.0):
+    Version 3.2.0 Changes:
+    - No more date parameters - encode/decode anytime!
+    - Simplified passphrase (no daily rotation)
+    - True asynchronous communications
+    
+    \b
+    Embedding Modes:
     - LSB mode (default): Full color output, higher capacity
     - DCT mode: Frequency domain, ~20% capacity, better stealth
     
     \b
-    DCT Options (v3.0.1):
+    DCT Options:
     - Color mode: grayscale (default) or color (preserves colors)
     - Output format: png (lossless) or jpeg (smaller, natural)
     """
@@ -104,7 +111,7 @@ def cli():
 @click.option('--rsa/--no-rsa', default=False, help='Generate an RSA key')
 @click.option('--pin-length', type=click.IntRange(6, 9), default=6, help='PIN length (6-9)')
 @click.option('--rsa-bits', type=click.Choice(['2048', '3072', '4096']), default='2048', help='RSA key size')
-@click.option('--words', type=click.IntRange(3, 12), default=3, help='Words per phrase (3-12)')
+@click.option('--words', type=click.IntRange(3, 12), default=4, help='Words per passphrase (default: 4, was 3 in v3.1)')
 @click.option('--output', '-o', type=click.Path(), help='Save RSA key to file (requires password)')
 @click.option('--password', '-p', help='Password for RSA key file')
 @click.option('--json', 'as_json', is_flag=True, help='Output as JSON')
@@ -112,12 +119,16 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
     """
     Generate credentials for encoding/decoding.
     
-    Creates daily passphrases and optionally a PIN and/or RSA key.
+    Creates a passphrase and optionally a PIN and/or RSA key.
     At least one of --pin or --rsa must be enabled.
     
+    v3.2.0: No more daily passphrases - use one strong passphrase!
+    Default increased to 4 words (from 3) for better security.
+    
     \b
     Examples:
         stegasoo generate
+        stegasoo generate --words 5
         stegasoo generate --rsa --rsa-bits 4096
         stegasoo generate --rsa -o mykey.pem -p "secretpassword"
         stegasoo generate --no-pin --rsa
@@ -137,17 +148,17 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
             use_rsa=rsa,
             pin_length=pin_length,
             rsa_bits=int(rsa_bits),
-            words_per_phrase=words
+            words_per_passphrase=words
         )
         
         if as_json:
             import json
             data = {
-                'phrases': creds.phrases,
+                'passphrase': creds.passphrase,
                 'pin': creds.pin,
                 'rsa_key': creds.rsa_key_pem,
                 'entropy': {
-                    'phrase': creds.phrase_entropy,
+                    'passphrase': creds.passphrase_entropy,
                     'pin': creds.pin_entropy,
                     'rsa': creds.rsa_entropy,
                     'total': creds.total_entropy,
@@ -159,7 +170,7 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
         # Pretty output
         click.echo()
         click.secho("=" * 60, fg='cyan')
-        click.secho("  STEGASOO CREDENTIALS", fg='cyan', bold=True)
+        click.secho("  STEGASOO CREDENTIALS (v3.2.0)", fg='cyan', bold=True)
         click.secho("=" * 60, fg='cyan')
         click.echo()
         
@@ -172,11 +183,8 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
             click.secho(f"    {creds.pin}", fg='bright_yellow', bold=True)
             click.echo()
         
-        click.secho("--- DAILY PHRASES ---", fg='green')
+        click.secho("--- PASSPHRASE ---", fg='green')
-        for day in DAY_NAMES:
+        click.secho(f"    {creds.passphrase}", fg='bright_white', bold=True)
-            phrase = creds.phrases[day]
-            click.echo(f"    {day:9} | ", nl=False)
-            click.secho(phrase, fg='bright_white')
         click.echo()
         
         if creds.rsa_key_pem:
@@ -193,7 +201,7 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
             click.echo()
         
         click.secho("--- SECURITY ---", fg='green')
-        click.echo(f"    Phrase entropy:  {creds.phrase_entropy} bits")
+        click.echo(f"    Passphrase entropy: {creds.passphrase_entropy} bits ({words} words)")
         if creds.pin:
             click.echo(f"    PIN entropy:        {creds.pin_entropy} bits")
         if creds.rsa_key_pem:
@@ -202,6 +210,9 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
         click.secho(f"    + photo entropy:    80-256 bits", dim=True)
         click.echo()
         
+        click.secho("NOTE: v3.2.0 removed date dependency - use this passphrase anytime!", fg='cyan')
+        click.echo()
+        
     except Exception as e:
         raise click.ClickException(str(e))
 
@@ -216,13 +227,12 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
 @click.option('--message', '-m', help='Text message to encode')
 @click.option('--message-file', '-f', type=click.Path(exists=True), help='Read text message from file')
 @click.option('--embed-file', '-e', type=click.Path(exists=True), help='Embed a file (binary)')
-@click.option('--phrase', '-p', required=True, help='Day phrase')
+@click.option('--passphrase', '-p', required=True, help='Passphrase (v3.2.0: no date needed!)')
 @click.option('--pin', help='Static PIN')
 @click.option('--key', '-k', type=click.Path(exists=True), help='RSA key file (.pem)')
 @click.option('--key-qr', type=click.Path(exists=True), help='RSA key from QR code image')
 @click.option('--key-password', help='RSA key password (for encrypted .pem files)')
 @click.option('--output', '-o', type=click.Path(), help='Output file (default: auto-generated)')
-@click.option('--date', 'date_str', help='Date override (YYYY-MM-DD)')
 @click.option('--mode', 'embed_mode', type=click.Choice(['lsb', 'dct']), default='lsb',
               help='Embedding mode: lsb (default, color) or dct (requires scipy)')
 @click.option('--dct-format', 'dct_output_format', type=click.Choice(['png', 'jpeg']), default='png',
@@ -230,20 +240,22 @@ def generate(pin, rsa, pin_length, rsa_bits, words, output, password, as_json):
 @click.option('--dct-color', 'dct_color_mode', type=click.Choice(['grayscale', 'color']), default='grayscale',
               help='DCT color mode: grayscale (default) or color (preserves original colors)')
 @click.option('--quiet', '-q', is_flag=True, help='Suppress output except errors')
-def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key, key_qr, 
+def encode_cmd(ref, carrier, message, message_file, embed_file, passphrase, pin, key, key_qr, 
-               key_password, output, date_str, embed_mode, dct_output_format, dct_color_mode, quiet):
+               key_password, output, embed_mode, dct_output_format, dct_color_mode, quiet):
     """
     Encode a secret message or file into an image.
     
-    Requires a reference photo, carrier image, and day phrase.
+    Requires a reference photo, carrier image, and passphrase.
     Must provide either --pin or --key/--key-qr (or both).
     
+    v3.2.0: No --date parameter needed! Encode and decode anytime.
+    
     For text messages, use -m or -f or pipe via stdin.
     For binary files, use -e/--embed-file.
     RSA key can be provided as a .pem file (--key) or QR code image (--key-qr).
     
     \b
-    Embedding Modes (v3.0):
+    Embedding Modes:
         --mode lsb   Spatial LSB embedding (default)
                      - Full color output (PNG/BMP)
                      - Higher capacity (~375 KB/megapixel)
@@ -254,7 +266,7 @@ def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key
                      - Better resistance to visual analysis
     
     \b
-    DCT Options (v3.0.1):
+    DCT Options:
         --dct-format png     Lossless output (default)
         --dct-format jpeg    Smaller file, more natural appearance
         
@@ -264,18 +276,14 @@ def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key
     \b
     Examples:
         # Text message with PIN (LSB mode, default)
-        stegasoo encode -r photo.jpg -c meme.png -p "apple forest" --pin 123456 -m "secret"
+        stegasoo encode -r photo.jpg -c meme.png -p "apple forest thunder mountain" --pin 123456 -m "secret"
         
         # DCT mode - grayscale PNG (traditional)
-        stegasoo encode -r photo.jpg -c meme.png -p "words" --pin 123456 -m "secret" --mode dct
+        stegasoo encode -r photo.jpg -c meme.png -p "secure words here now" --pin 123456 -m "secret" --mode dct
         
-        # DCT mode - color JPEG (v3.0.1)
+        # DCT mode - color JPEG
-        stegasoo encode -r photo.jpg -c meme.png -p "words" --pin 123456 -m "secret" \
+        stegasoo encode -r photo.jpg -c meme.png -p "my strong passphrase" --pin 123456 -m "secret" \
             --mode dct --dct-color color --dct-format jpeg
-        
-        # DCT mode - color PNG (best quality + color preservation)
-        stegasoo encode -r photo.jpg -c meme.png -p "words" --pin 123456 -m "secret" \
-            --mode dct --dct-color color --dct-format png
     """
     # Check DCT mode availability
     if embed_mode == 'dct' and not has_dct_support():
@@ -365,15 +373,15 @@ def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key
                 mode_desc += f" ({dct_color_mode}, {dct_output_format.upper()})"
             click.echo(f"Mode: {mode_desc} ({fit_check['usage_percent']:.1f}% capacity)")
         
+        # v3.2.0: No date_str parameter
         result = encode(
             message=payload,
             reference_photo=ref_photo,
             carrier_image=carrier_image,
-            day_phrase=phrase,
+            passphrase=passphrase,  # Renamed from day_phrase
             pin=pin or "",
             rsa_key_data=rsa_key_data,
             rsa_password=effective_key_password,
-            date_str=date_str,
             embed_mode=embed_mode,
             dct_output_format=dct_output_format,
             dct_color_mode=dct_color_mode,
@@ -389,15 +397,15 @@ def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key
         out_path.write_bytes(result.stego_image)
         
         if not quiet:
-            click.secho(f"[OK] Encoded successfully!", fg='green')
+            click.secho(f"✓ Encoded successfully!", fg='green')
             click.echo(f"  Output: {out_path}")
             click.echo(f"  Size: {len(result.stego_image):,} bytes")
             click.echo(f"  Capacity used: {result.capacity_percent:.1f}%")
-            click.echo(f"  Date: {result.date_used}")
             if embed_mode == 'dct':
                 color_note = "color preserved" if dct_color_mode == 'color' else "grayscale"
                 format_note = dct_output_format.upper()
                 click.secho(f"  DCT output: {format_note} ({color_note})", dim=True)
+            click.secho("  (v3.2.0: No date needed to decode!)", fg='cyan', dim=True)
         
     except StegasooError as e:
         raise click.ClickException(str(e))
@@ -414,7 +422,7 @@ def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key
 @cli.command()
 @click.option('--ref', '-r', required=True, type=click.Path(exists=True), help='Reference photo')
 @click.option('--stego', '-s', required=True, type=click.Path(exists=True), help='Stego image')
-@click.option('--phrase', '-p', required=True, help='Day phrase')
+@click.option('--passphrase', '-p', required=True, help='Passphrase')
 @click.option('--pin', help='Static PIN')
 @click.option('--key', '-k', type=click.Path(exists=True), help='RSA key file (.pem)')
 @click.option('--key-qr', type=click.Path(exists=True), help='RSA key from QR code image')
@@ -424,7 +432,7 @@ def encode_cmd(ref, carrier, message, message_file, embed_file, phrase, pin, key
               help='Extraction mode: auto (default), lsb, or dct')
 @click.option('--quiet', '-q', is_flag=True, help='Output only the content (for text) or suppress messages (for files)')
 @click.option('--force', is_flag=True, help='Overwrite existing output file')
-def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed_mode, quiet, force):
+def decode_cmd(ref, stego, passphrase, pin, key, key_qr, key_password, output, embed_mode, quiet, force):
     """
     Decode a secret message or file from a stego image.
     
@@ -432,11 +440,13 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
     Automatically detects whether content is text or a file.
     RSA key can be provided as a .pem file (--key) or QR code image (--key-qr).
     
+    v3.2.0: No --date parameter needed! Just use your passphrase.
+    
     Note: Extraction works the same regardless of whether the image was
     created with color mode or grayscale mode - both use the same Y channel.
     
     \b
-    Extraction Modes (v3.0):
+    Extraction Modes:
         --mode auto  Auto-detect (default) - tries LSB first, then DCT
         --mode lsb   Only try LSB extraction
         --mode dct   Only try DCT extraction (requires scipy)
@@ -444,16 +454,16 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
     \b
     Examples:
         # Decode with PIN (auto-detect mode)
-        stegasoo decode -r photo.jpg -s stego.png -p "apple forest thunder" --pin 123456
+        stegasoo decode -r photo.jpg -s stego.png -p "apple forest thunder mountain" --pin 123456
         
         # Explicitly specify DCT mode
-        stegasoo decode -r photo.jpg -s stego.png -p "words" --pin 123456 --mode dct
+        stegasoo decode -r photo.jpg -s stego.png -p "my passphrase here" --pin 123456 --mode dct
         
         # Decode with RSA key file
-        stegasoo decode -r photo.jpg -s stego.png -p "words" -k mykey.pem
+        stegasoo decode -r photo.jpg -s stego.png -p "strong words" -k mykey.pem
         
         # Save output to file
-        stegasoo decode -r photo.jpg -s stego.png -p "words" --pin 123456 -o output.txt
+        stegasoo decode -r photo.jpg -s stego.png -p "passphrase" --pin 123456 -o output.txt
     """
     # Check DCT mode availability
     if embed_mode == 'dct' and not has_dct_support():
@@ -495,10 +505,11 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
         ref_photo = Path(ref).read_bytes()
         stego_image = Path(stego).read_bytes()
         
+        # v3.2.0: No date_str parameter
         result = decode(
             stego_image=stego_image,
             reference_photo=ref_photo,
-            day_phrase=phrase,
+            passphrase=passphrase,  # Renamed from day_phrase
             pin=pin or "",
             rsa_key_data=rsa_key_data,
             rsa_password=effective_key_password,
@@ -522,7 +533,7 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
             out_path.write_bytes(result.file_data)
             
             if not quiet:
-                click.secho("[OK] Decoded file successfully!", fg='green')
+                click.secho("✓ Decoded file successfully!", fg='green')
                 click.echo(f"  Saved to: {out_path}")
                 click.echo(f"  Size: {len(result.file_data):,} bytes")
                 if result.mime_type:
@@ -532,13 +543,13 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
             if output:
                 Path(output).write_text(result.message)
                 if not quiet:
-                    click.secho("[OK] Decoded successfully!", fg='green')
+                    click.secho("✓ Decoded successfully!", fg='green')
                     click.echo(f"  Saved to: {output}")
             else:
                 if quiet:
                     click.echo(result.message)
                 else:
-                    click.secho("[OK] Decoded successfully!", fg='green')
+                    click.secho("✓ Decoded successfully!", fg='green')
                     click.echo()
                     click.echo(result.message)
         
@@ -557,7 +568,7 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
 @cli.command()
 @click.option('--ref', '-r', required=True, type=click.Path(exists=True), help='Reference photo')
 @click.option('--stego', '-s', required=True, type=click.Path(exists=True), help='Stego image')
-@click.option('--phrase', '-p', required=True, help='Day phrase')
+@click.option('--passphrase', '-p', required=True, help='Passphrase')
 @click.option('--pin', help='Static PIN')
 @click.option('--key', '-k', type=click.Path(exists=True), help='RSA key file (.pem)')
 @click.option('--key-qr', type=click.Path(exists=True), help='RSA key from QR code image')
@@ -565,7 +576,7 @@ def decode_cmd(ref, stego, phrase, pin, key, key_qr, key_password, output, embed
 @click.option('--mode', 'embed_mode', type=click.Choice(['auto', 'lsb', 'dct']), default='auto',
               help='Extraction mode: auto (default), lsb, or dct')
 @click.option('--json', 'as_json', is_flag=True, help='Output as JSON')
-def verify(ref, stego, phrase, pin, key, key_qr, key_password, embed_mode, as_json):
+def verify(ref, stego, passphrase, pin, key, key_qr, key_password, embed_mode, as_json):
     """
     Verify that a stego image can be decoded without extracting the message.
     
@@ -574,11 +585,11 @@ def verify(ref, stego, phrase, pin, key, key_qr, key_password, embed_mode, as_js
     
     \b
     Examples:
-        stegasoo verify -r photo.jpg -s stego.png -p "apple forest thunder" --pin 123456
+        stegasoo verify -r photo.jpg -s stego.png -p "my passphrase" --pin 123456
         
-        stegasoo verify -r photo.jpg -s stego.png -p "words" -k mykey.pem --json
+        stegasoo verify -r photo.jpg -s stego.png -p "words here" -k mykey.pem --json
         
-        stegasoo verify -r photo.jpg -s stego.png -p "words" --pin 123456 --mode dct
+        stegasoo verify -r photo.jpg -s stego.png -p "test phrase" --pin 123456 --mode dct
     """
     # Check DCT mode availability
     if embed_mode == 'dct' and not has_dct_support():
@@ -620,7 +631,7 @@ def verify(ref, stego, phrase, pin, key, key_qr, key_password, embed_mode, as_js
         result = decode(
             stego_image=stego_image,
             reference_photo=ref_photo,
-            day_phrase=phrase,
+            passphrase=passphrase,  # v3.2.0: Renamed from day_phrase
             pin=pin or "",
             rsa_key_data=rsa_key_data,
             rsa_password=effective_key_password,
@@ -639,10 +650,6 @@ def verify(ref, stego, phrase, pin, key, key_qr, key_password, embed_mode, as_js
             payload_type = "text"
             payload_desc = f"{payload_size} bytes"
         
-        # Get date info
-        date_encoded = result.date_encoded
-        day_name = get_day_from_date(date_encoded) if date_encoded else None
-        
         if as_json:
             import json
             output = {
@@ -650,19 +657,15 @@ def verify(ref, stego, phrase, pin, key, key_qr, key_password, embed_mode, as_js
                 "stego_file": stego,
                 "payload_type": payload_type,
                 "payload_size": payload_size,
-                "date_encoded": date_encoded,
-                "day_encoded": day_name,
             }
             if result.is_file:
                 output["filename"] = result.filename
                 output["mime_type"] = result.mime_type
             click.echo(json.dumps(output, indent=2))
         else:
-            click.secho("[OK] Valid stego image", fg='green', bold=True)
+            click.secho("✓ Valid stego image", fg='green', bold=True)
             click.echo(f"  Payload:  {payload_type} ({payload_desc})")
             click.echo(f"  Size:     {payload_size:,} bytes")
-            if date_encoded:
-                click.echo(f"  Encoded:  {date_encoded} ({day_name})")
         
     except (DecryptionError, ExtractionError) as e:
         if as_json:
@@ -675,7 +678,7 @@ def verify(ref, stego, phrase, pin, key, key_qr, key_password, embed_mode, as_js
             click.echo(json.dumps(output, indent=2))
             sys.exit(1)
         else:
-            click.secho("[FAIL] Verification failed", fg='red', bold=True)
+            click.secho("✗ Verification failed", fg='red', bold=True)
             click.echo(f"  Error: {e}")
             sys.exit(1)
     except StegasooError as e:
@@ -695,8 +698,7 @@ def info(image, as_json):
     """
     Show information about an image.
     
-    Displays dimensions, capacity for both LSB and DCT modes,
+    Displays dimensions, capacity for both LSB and DCT modes.
-    and attempts to detect date from filename.
     """
     try:
         image_data = Path(image).read_bytes()
@@ -708,10 +710,6 @@ def info(image, as_json):
         # Get capacity comparison
         comparison = compare_modes(image_data)
         
-        # Try to get date from filename
-        date_str = parse_date_from_filename(image)
-        day_name = get_day_from_date(date_str) if date_str else None
-        
         if as_json:
             import json
             output = {
@@ -736,9 +734,6 @@ def info(image, as_json):
                     },
                 },
             }
-            if date_str:
-                output["embed_date"] = date_str
-                output["embed_day"] = day_name
             click.echo(json.dumps(output, indent=2))
             return
         
@@ -753,17 +748,13 @@ def info(image, as_json):
         click.secho("  Capacity:", bold=True)
         click.echo(f"    LSB mode:  ~{comparison['lsb']['capacity_bytes']:,} bytes ({comparison['lsb']['capacity_kb']:.1f} KB)")
         
-        dct_status = "[OK]" if comparison['dct']['available'] else "[X] (scipy not installed)"
+        dct_status = "✓" if comparison['dct']['available'] else "✗ (scipy not installed)"
         click.echo(f"    DCT mode:  ~{comparison['dct']['capacity_bytes']:,} bytes ({comparison['dct']['capacity_kb']:.1f} KB) {dct_status}")
         click.echo(f"    DCT ratio: {comparison['dct']['ratio_vs_lsb']:.1f}% of LSB")
         
         if comparison['dct']['available']:
             click.secho("    DCT options: grayscale/color, png/jpeg", dim=True)
         
-        if date_str:
-            click.echo()
-            click.echo(f"  Embed date:  {date_str} ({day_name})")
-        
         click.echo()
         
     except Exception as e:
@@ -839,7 +830,7 @@ def compare(image, payload_size, as_json):
         click.secho("  +--- LSB Mode ---", fg='green')
         click.echo(f"  | Capacity:  {comparison['lsb']['capacity_bytes']:,} bytes ({comparison['lsb']['capacity_kb']:.1f} KB)")
         click.echo(f"  | Output:    {comparison['lsb']['output']}")
-        click.echo(f"  | Status:    [OK] Available")
+        click.echo(f"  | Status:    ✓ Available")
         click.echo("  |")
         
         # DCT mode
@@ -847,11 +838,11 @@ def compare(image, payload_size, as_json):
         click.echo(f"  | Capacity:  {comparison['dct']['capacity_bytes']:,} bytes ({comparison['dct']['capacity_kb']:.1f} KB)")
         click.echo(f"  | Ratio:     {comparison['dct']['ratio_vs_lsb']:.1f}% of LSB capacity")
         if comparison['dct']['available']:
-            click.echo(f"  | Status:    [OK] Available")
+            click.echo(f"  | Status:    ✓ Available")
             click.echo(f"  | Formats:   PNG (lossless), JPEG (smaller)")
             click.echo(f"  | Colors:    Grayscale (default), Color (v3.0.1)")
         else:
-            click.secho(f"  | Status:    [X] Requires scipy (pip install scipy)", fg='yellow')
+            click.secho(f"  | Status:    ✗ Requires scipy (pip install scipy)", fg='yellow')
         click.echo("  |")
         
         # Payload check
@@ -862,8 +853,8 @@ def compare(image, payload_size, as_json):
             fits_lsb = payload_size <= comparison['lsb']['capacity_bytes']
             fits_dct = payload_size <= comparison['dct']['capacity_bytes']
             
-            lsb_icon = "[OK]" if fits_lsb else "[X]"
+            lsb_icon = "✓" if fits_lsb else "✗"
-            dct_icon = "[OK]" if fits_dct else "[X]"
+            dct_icon = "✓" if fits_dct else "✗"
             lsb_color = 'green' if fits_lsb else 'red'
             dct_color = 'green' if fits_dct else 'red'
             
@@ -884,7 +875,7 @@ def compare(image, payload_size, as_json):
             elif fits_lsb:
                 click.echo("  LSB mode (payload too large for DCT)")
             else:
-                click.secho("  [X] Payload too large for both modes!", fg='red')
+                click.secho("  ✗ Payload too large for both modes!", fg='red')
         else:
             click.echo("  LSB for larger payloads, DCT for better stealth")
             click.echo("  DCT supports color output with --dct-color color")
@@ -931,7 +922,7 @@ def strip_metadata_cmd(image, output, output_format, quiet):
         out_path.write_bytes(clean_data)
         
         if not quiet:
-            click.secho("[OK] Metadata stripped", fg='green')
+            click.secho("✓ Metadata stripped", fg='green')
             click.echo(f"  Input:  {image} ({original_size:,} bytes)")
             click.echo(f"  Output: {out_path} ({len(clean_data):,} bytes)")
         
@@ -951,12 +942,12 @@ def modes():
     Displays which modes are available and their characteristics.
     """
     click.echo()
-    click.secho("=== Stegasoo Embedding Modes ===", fg='cyan', bold=True)
+    click.secho("=== Stegasoo Embedding Modes (v3.2.0) ===", fg='cyan', bold=True)
     click.echo()
     
     # LSB Mode
     click.secho("  LSB Mode (Spatial LSB)", fg='green', bold=True)
-    click.echo("    Status:      [OK] Always available")
+    click.echo("    Status:      ✓ Always available")
     click.echo("    Output:      PNG/BMP (full color)")
     click.echo("    Capacity:    ~375 KB per megapixel")
     click.echo("    Use case:    Larger payloads, color preservation")
@@ -966,16 +957,16 @@ def modes():
     # DCT Mode
     click.secho("  DCT Mode (Frequency Domain)", fg='blue', bold=True)
     if has_dct_support():
-        click.echo("    Status:      [OK] Available")
+        click.echo("    Status:      ✓ Available")
     else:
-        click.secho("    Status:      [X] Requires scipy", fg='yellow')
+        click.secho("    Status:      ✗ Requires scipy", fg='yellow')
         click.echo("    Install:     pip install scipy")
     click.echo("    Capacity:    ~75 KB per megapixel (~20% of LSB)")
     click.echo("    Use case:    Better stealth, frequency domain hiding")
     click.echo("    CLI flag:    --mode dct")
     click.echo()
     
-    # DCT Options (v3.0.1)
+    # DCT Options
     click.secho("  DCT Options (v3.0.1)", fg='magenta', bold=True)
     click.echo("    Output format:")
     click.echo("      --dct-format png     Lossless, larger file (default)")
@@ -986,6 +977,13 @@ def modes():
     click.echo("      --dct-color color       Preserves original colors")
     click.echo()
     
+    # v3.2.0 Note
+    click.secho("  v3.2.0 Changes:", fg='cyan', bold=True)
+    click.echo("    ✓ No date parameters needed")
+    click.echo("    ✓ Single passphrase (no daily rotation)")
+    click.echo("    ✓ True asynchronous communications")
+    click.echo()
+    
     # Examples
     click.secho("  Examples:", dim=True)
     click.echo("    # Traditional DCT (grayscale PNG)")

src/stegasoo/COMPLETE_CHANGE_SUMMARY_V3.2.0.md

@@ -0,0 +1,374 @@
+# Stegasoo v3.2.0 - Complete Change Summary
+
+## Overview
+
+This update makes two major breaking changes to Stegasoo:
+1. **Remove date dependency** - Date no longer used in cryptographic operations
+2. **Rename day_phrase → passphrase** - Reflects removal of daily rotation requirement
+
+## Version Information
+
+- **Previous**: v3.1.0 (date-dependent, day_phrase)
+- **Current**: v3.2.0 (date-independent, passphrase)
+- **Format Version**: 3 → 4 (breaking change)
+- **Compatibility**: NOT backward compatible with v3.1.0
+
+## Files Modified
+
+### Core Files (MUST UPDATE)
+
+1. **crypto.py** ✅ Updated
+   - Removed `date_str` parameter from all functions
+   - Renamed `day_phrase` → `passphrase` in all functions
+   - Removed date from key derivation material
+   - Simplified header format (no date field)
+   - Updated error messages
+
+2. **constants.py** ✅ Updated
+   - Version: `__version__ = "3.2.0"`
+   - Format: `FORMAT_VERSION = 4`
+   - Added passphrase constants:
+     - `MIN_PASSPHRASE_WORDS = 3`
+     - `MAX_PASSPHRASE_WORDS = 12`
+     - `DEFAULT_PASSPHRASE_WORDS = 4` (increased from 3)
+     - `RECOMMENDED_PASSPHRASE_WORDS = 4`
+   - Kept legacy aliases for transition
+
+3. **models.py** ✅ Updated
+   - `Credentials`: Changed from `phrases: dict` → `passphrase: str`
+   - `EncodeInput`: Renamed `day_phrase` → `passphrase`, removed `date_str`
+   - `DecodeInput`: Renamed `day_phrase` → `passphrase`
+   - `EncodeResult`: Made `date_used` optional (cosmetic only)
+   - `DecodeResult`: `date_encoded` always None in v3.2.0
+   - `ValidationResult`: Added `warning` field
+
+4. **validation.py** ✅ Updated
+   - Renamed `validate_phrase()` → `validate_passphrase()`
+   - Added word count validation with warnings
+   - Recommends 4+ words for good security
+   - Updated error messages
+
+### Files Needing Updates
+
+5. **__init__.py** - Public API
+   - [ ] `encode()`: Remove `date_str`, rename `day_phrase` → `passphrase`
+   - [ ] `encode_file()`: Same changes
+   - [ ] `encode_bytes()`: Same changes
+   - [ ] `decode()`: Remove `date_str`, rename `day_phrase` → `passphrase`
+   - [ ] `decode_text()`: Same changes
+   - [ ] Update all docstrings
+
+6. **keygen.py** - Key generation
+   - [ ] `generate_day_phrases()` → `generate_passphrases()` or keep with new implementation
+   - [ ] `generate_credentials()`: Update to use single passphrase
+   - [ ] Update `Credentials` creation
+
+7. **batch.py** - Batch operations
+   - [ ] `BatchCredentials`: Rename `day_phrase` → `passphrase`
+   - [ ] Update all batch functions
+
+8. **cli.py** - Command line
+   - [ ] `--phrase` → `--passphrase` (or keep `--phrase` for simplicity)
+   - [ ] Update help text
+   - [ ] Update credentials dict creation
+
+9. **steganography.py** - No changes needed
+   - Uses keys from crypto module, doesn't directly handle phrases/dates
+
+10. **dct_steganography.py** - No changes needed
+    - Uses keys from crypto module
+
+### Optional/Documentation Files
+
+11. **utils.py** - Keep as-is (organizational functions)
+12. **debug.py** - No changes needed
+13. **exceptions.py** - No changes needed
+14. **compression.py** - No changes needed
+15. **qr_utils.py** - No changes needed
+
+## Key Changes Breakdown
+
+### 1. Function Signatures
+
+**Before (v3.1.0):**
+```python
+def derive_hybrid_key(
+    photo_data: bytes,
+    day_phrase: str,
+    date_str: str,
+    salt: bytes,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None
+) -> bytes:
+```
+
+**After (v3.2.0):**
+```python
+def derive_hybrid_key(
+    photo_data: bytes,
+    passphrase: str,
+    salt: bytes,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None
+) -> bytes:
+```
+
+### 2. Key Derivation Material
+
+**Before:**
+```python
+key_material = (
+    photo_hash +
+    day_phrase.lower().encode() +
+    pin.encode() +
+    date_str.encode() +  # ← REMOVED
+    salt
+)
+```
+
+**After:**
+```python
+key_material = (
+    photo_hash +
+    passphrase.lower().encode() +
+    pin.encode() +
+    salt
+)
+```
+
+### 3. Header Format
+
+**Before (v3.1.0):** 66+ bytes
+```
+[Magic:4][Version:1][DateLen:1][Date:10][Salt:32][IV:12][Tag:16][Ciphertext]
+```
+
+**After (v3.2.0):** 65 bytes
+```
+[Magic:4][Version:1][Salt:32][IV:12][Tag:16][Ciphertext]
+```
+
+### 4. Public API
+
+**Before:**
+```python
+# Encoding
+result = encode(
+    message="Secret",
+    reference_photo=photo,
+    carrier_image=carrier,
+    day_phrase="apple forest thunder",
+    pin="123456",
+    date_str="2025-01-15"
+)
+
+# Decoding
+decoded = decode(
+    stego_image=stego,
+    reference_photo=photo,
+    day_phrase="apple forest thunder",
+    pin="123456",
+    date_str="2025-01-15"
+)
+```
+
+**After:**
+```python
+# Encoding
+result = encode(
+    message="Secret",
+    reference_photo=photo,
+    carrier_image=carrier,
+    passphrase="apple forest thunder mountain",
+    pin="123456"
+)
+
+# Decoding
+decoded = decode(
+    stego_image=stego,
+    reference_photo=photo,
+    passphrase="apple forest thunder mountain",
+    pin="123456"
+)
+```
+
+## Migration Path
+
+### For Users with v3.1.0 Messages
+
+1. **Before upgrading**, decode all messages with v3.1.0:
+   ```bash
+   # Using v3.1.0
+   python decode_all.py
+   ```
+
+2. Save the decoded content
+
+3. Upgrade to v3.2.0
+
+4. Re-encode with v3.2.0 if needed
+
+### For Developers
+
+1. Update the 4 core files: crypto.py, constants.py, models.py, validation.py
+
+2. Update remaining files in order:
+   - `__init__.py` (public API - critical)
+   - `keygen.py` (credential generation)
+   - `batch.py` (batch operations)
+   - `cli.py` (command line)
+
+3. Run tests to verify:
+   ```bash
+   pytest tests/ -v
+   ```
+
+4. Update documentation and examples
+
+## Benefits
+
+### Simplicity
+- ❌ Before: 3 parameters (day_phrase, pin, date)
+- ✅ After: 2 parameters (passphrase, pin)
+
+### User Experience
+- ❌ Before: "What date did I encode this?" "Which day's phrase?"
+- ✅ After: Just use your passphrase
+
+### Asynchronous Ready
+- ❌ Before: Must know encoding date
+- ✅ After: Decode anytime
+
+### Less Metadata
+- ❌ Before: Date stored in header
+- ✅ After: No temporal metadata
+
+## Security Considerations
+
+### Entropy Comparison
+
+**v3.1.0:**
+- Photo hash: ~128 bits
+- Day phrase (3 words): ~33 bits
+- PIN (6 digits): ~20 bits
+- Date: ~33 bits (10 digits)
+- **Total: ~214 bits**
+
+**v3.2.0:**
+- Photo hash: ~128 bits
+- Passphrase (4 words): ~44 bits
+- PIN (6 digits): ~20 bits
+- **Total: ~192 bits**
+
+**Mitigation:** Recommend longer passphrases (4-5 words vs 3)
+
+### Best Practices for v3.2.0
+
+1. **Use 4+ word passphrases** (increased from 3)
+2. **Keep using PINs** (additional 20 bits)
+3. **Protect reference photo** (still critical)
+4. **Consider RSA keys** for highest security
+
+## Testing Checklist
+
+- [ ] Unit tests pass
+- [ ] Integration tests pass
+- [ ] Encode/decode round-trip works
+- [ ] File payloads work
+- [ ] LSB mode works
+- [ ] DCT mode works
+- [ ] Batch operations work
+- [ ] CLI commands work
+- [ ] Error messages are clear
+- [ ] Validation works correctly
+- [ ] No references to "day_phrase" remain
+- [ ] No date parameters remain (except cosmetic)
+
+## Documentation Updates Needed
+
+- [ ] README.md - Update all examples
+- [ ] API documentation - Update function signatures
+- [ ] Tutorials - Remove date parameters
+- [ ] CHANGELOG.md - Add v3.2.0 entry
+- [ ] Migration guide - How to upgrade from v3.1.0
+- [ ] Examples directory - Update all scripts
+
+## Backward Compatibility Strategy
+
+### Option 1: Clean Break (Recommended)
+- No compatibility code
+- Clear version separation
+- Users must migrate manually
+
+### Option 2: Temporary Wrapper
+```python
+def encode(
+    message,
+    reference_photo,
+    carrier_image,
+    passphrase: str = None,
+    day_phrase: str = None,  # Deprecated
+    date_str: str = None,     # Deprecated
+    pin: str = "",
+    ...
+):
+    if day_phrase and not passphrase:
+        import warnings
+        warnings.warn("day_phrase deprecated, use passphrase", DeprecationWarning)
+        passphrase = day_phrase
+    
+    if date_str:
+        warnings.warn("date_str no longer used", DeprecationWarning)
+    
+    # ... rest of function
+```
+
+## Release Checklist
+
+- [ ] All files updated
+- [ ] Tests passing
+- [ ] Documentation updated
+- [ ] Migration guide written
+- [ ] CHANGELOG.md updated
+- [ ] Version bumped to 3.2.0
+- [ ] Git tag created: v3.2.0
+- [ ] PyPI package published
+- [ ] Release notes published
+- [ ] Users notified of breaking changes
+
+## Quick Reference
+
+### Search and Replace Patterns
+
+Safe to replace globally:
+- `day_phrase` → `passphrase`
+- `day phrase` → `passphrase`
+- `Day phrase` → `Passphrase`
+- `DEFAULT_PHRASE_WORDS` → `DEFAULT_PASSPHRASE_WORDS`
+
+Do NOT replace:
+- `DAY_NAMES` (keep for utilities)
+- `get_day_from_date` (keep for utilities)
+- `generate_day_phrases` (rename function itself)
+
+### Error Message Updates
+
+- "Day phrase is required" → "Passphrase is required"
+- "Check your phrase, PIN" → "Check your passphrase, PIN"
+- "the day's phrase" → "the passphrase"
+- "today's passphrase" → "passphrase"
+
+## Support
+
+For issues or questions during migration:
+1. Check the migration guide
+2. Review the comparison document
+3. Look at updated examples
+4. File an issue on GitHub
+
+---
+
+**Status:** 
+✅ Core files updated (crypto, constants, models, validation)
+⏳ Remaining files need updates (__init__, keygen, batch, cli)
+📝 Documentation updates pending

src/stegasoo/channel.py

@@ -0,0 +1,448 @@
+"""
+Channel Key Management for Stegasoo
+
+A channel key ties encode/decode operations to a specific deployment or group.
+Messages encoded with one channel key can only be decoded by systems with the
+same channel key configured.
+
+Use cases:
+- Organization deployment: IT sets a company-wide channel key
+- Friend groups: Share a channel key for private communication
+- Air-gapped systems: Generate unique key per installation
+- Public instances: No channel key = compatible with any instance without a channel key
+
+Storage priority:
+1. Environment variable: STEGASOO_CHANNEL_KEY
+2. Config file: ~/.stegasoo/channel.key or ./config/channel.key
+3. None (public mode - compatible with any instance without a channel key)
+"""
+
+import os
+import secrets
+import hashlib
+import re
+from pathlib import Path
+from typing import Optional, List
+
+from .debug import debug
+
+# Channel key format: 8 groups of 4 alphanumeric chars (32 chars total)
+# Example: ABCD-1234-EFGH-5678-IJKL-9012-MNOP-3456
+CHANNEL_KEY_PATTERN = re.compile(r'^[A-Z0-9]{4}(-[A-Z0-9]{4}){7}$')
+CHANNEL_KEY_LENGTH = 32  # Characters (excluding dashes)
+CHANNEL_KEY_FORMATTED_LENGTH = 39  # With dashes
+
+# Environment variable name
+CHANNEL_KEY_ENV_VAR = 'STEGASOO_CHANNEL_KEY'
+
+# Config locations (in priority order)
+CONFIG_LOCATIONS = [
+    Path('./config/channel.key'),                   # Project config
+    Path.home() / '.stegasoo' / 'channel.key',      # User config
+]
+
+
+def generate_channel_key() -> str:
+    """
+    Generate a new random channel key.
+    
+    Returns:
+        Formatted channel key (e.g., "ABCD-1234-EFGH-5678-IJKL-9012-MNOP-3456")
+        
+    Example:
+        >>> key = generate_channel_key()
+        >>> len(key)
+        39
+    """
+    # Generate 32 random alphanumeric characters
+    alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
+    raw_key = ''.join(secrets.choice(alphabet) for _ in range(CHANNEL_KEY_LENGTH))
+    
+    formatted = format_channel_key(raw_key)
+    debug.print(f"Generated channel key: {get_channel_fingerprint(formatted)}")
+    return formatted
+
+
+def format_channel_key(raw_key: str) -> str:
+    """
+    Format a raw key string into the standard format.
+    
+    Args:
+        raw_key: Raw key string (with or without dashes)
+        
+    Returns:
+        Formatted key with dashes (XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX)
+        
+    Raises:
+        ValueError: If key is invalid length or contains invalid characters
+        
+    Example:
+        >>> format_channel_key("ABCD1234EFGH5678IJKL9012MNOP3456")
+        "ABCD-1234-EFGH-5678-IJKL-9012-MNOP-3456"
+    """
+    # Remove any existing dashes, spaces, and convert to uppercase
+    clean = raw_key.replace('-', '').replace(' ', '').upper()
+    
+    if len(clean) != CHANNEL_KEY_LENGTH:
+        raise ValueError(
+            f"Channel key must be {CHANNEL_KEY_LENGTH} characters (got {len(clean)})"
+        )
+    
+    # Validate characters
+    if not all(c in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789' for c in clean):
+        raise ValueError("Channel key must contain only letters A-Z and digits 0-9")
+    
+    # Format with dashes every 4 characters
+    return '-'.join(clean[i:i+4] for i in range(0, CHANNEL_KEY_LENGTH, 4))
+
+
+def validate_channel_key(key: str) -> bool:
+    """
+    Validate a channel key format.
+    
+    Args:
+        key: Channel key to validate
+        
+    Returns:
+        True if valid format, False otherwise
+        
+    Example:
+        >>> validate_channel_key("ABCD-1234-EFGH-5678-IJKL-9012-MNOP-3456")
+        True
+        >>> validate_channel_key("invalid")
+        False
+    """
+    if not key:
+        return False
+    
+    try:
+        formatted = format_channel_key(key)
+        return bool(CHANNEL_KEY_PATTERN.match(formatted))
+    except ValueError:
+        return False
+
+
+def get_channel_key() -> Optional[str]:
+    """
+    Get the current channel key from environment or config.
+    
+    Checks in order:
+    1. STEGASOO_CHANNEL_KEY environment variable
+    2. ./config/channel.key file
+    3. ~/.stegasoo/channel.key file
+    
+    Returns:
+        Channel key if configured, None if in public mode
+        
+    Example:
+        >>> key = get_channel_key()
+        >>> if key:
+        ...     print("Private channel")
+        ... else:
+        ...     print("Public mode")
+    """
+    # 1. Check environment variable
+    env_key = os.environ.get(CHANNEL_KEY_ENV_VAR, '').strip()
+    if env_key:
+        if validate_channel_key(env_key):
+            debug.print(f"Channel key from environment: {get_channel_fingerprint(env_key)}")
+            return format_channel_key(env_key)
+        else:
+            debug.print(f"Warning: Invalid {CHANNEL_KEY_ENV_VAR} format, ignoring")
+    
+    # 2. Check config files
+    for config_path in CONFIG_LOCATIONS:
+        if config_path.exists():
+            try:
+                key = config_path.read_text().strip()
+                if key and validate_channel_key(key):
+                    debug.print(f"Channel key from {config_path}: {get_channel_fingerprint(key)}")
+                    return format_channel_key(key)
+            except (IOError, PermissionError) as e:
+                debug.print(f"Could not read {config_path}: {e}")
+                continue
+    
+    # 3. No channel key configured (public mode)
+    debug.print("No channel key configured (public mode)")
+    return None
+
+
+def set_channel_key(key: str, location: str = 'project') -> Path:
+    """
+    Save a channel key to config file.
+    
+    Args:
+        key: Channel key to save (will be formatted)
+        location: 'project' for ./config/ or 'user' for ~/.stegasoo/
+        
+    Returns:
+        Path where key was saved
+        
+    Raises:
+        ValueError: If key format is invalid
+        
+    Example:
+        >>> path = set_channel_key("ABCD1234EFGH5678IJKL9012MNOP3456")
+        >>> print(path)
+        ./config/channel.key
+    """
+    formatted = format_channel_key(key)
+    
+    if location == 'user':
+        config_path = Path.home() / '.stegasoo' / 'channel.key'
+    else:
+        config_path = Path('./config/channel.key')
+    
+    # Create directory if needed
+    config_path.parent.mkdir(parents=True, exist_ok=True)
+    
+    # Write key with newline
+    config_path.write_text(formatted + '\n')
+    
+    # Set restrictive permissions (owner read/write only)
+    try:
+        config_path.chmod(0o600)
+    except (OSError, AttributeError):
+        pass  # Windows doesn't support chmod the same way
+    
+    debug.print(f"Channel key saved to {config_path}")
+    return config_path
+
+
+def clear_channel_key(location: str = 'all') -> List[Path]:
+    """
+    Remove channel key configuration.
+    
+    Args:
+        location: 'project', 'user', or 'all'
+        
+    Returns:
+        List of paths that were deleted
+        
+    Example:
+        >>> deleted = clear_channel_key('all')
+        >>> print(f"Removed {len(deleted)} files")
+    """
+    deleted = []
+    
+    paths_to_check = []
+    if location in ('project', 'all'):
+        paths_to_check.append(Path('./config/channel.key'))
+    if location in ('user', 'all'):
+        paths_to_check.append(Path.home() / '.stegasoo' / 'channel.key')
+    
+    for path in paths_to_check:
+        if path.exists():
+            try:
+                path.unlink()
+                deleted.append(path)
+                debug.print(f"Removed channel key: {path}")
+            except (IOError, PermissionError) as e:
+                debug.print(f"Could not remove {path}: {e}")
+    
+    return deleted
+
+
+def get_channel_key_hash(key: Optional[str] = None) -> Optional[bytes]:
+    """
+    Get the channel key as a 32-byte hash suitable for key derivation.
+    
+    This hash is mixed into the Argon2 key derivation to bind
+    encryption to a specific channel.
+    
+    Args:
+        key: Channel key (if None, reads from config)
+        
+    Returns:
+        32-byte SHA-256 hash of channel key, or None if no channel key
+        
+    Example:
+        >>> hash_bytes = get_channel_key_hash()
+        >>> if hash_bytes:
+        ...     print(f"Hash: {len(hash_bytes)} bytes")
+    """
+    if key is None:
+        key = get_channel_key()
+    
+    if not key:
+        return None
+    
+    # Hash the formatted key to get consistent 32 bytes
+    formatted = format_channel_key(key)
+    return hashlib.sha256(formatted.encode('utf-8')).digest()
+
+
+def get_channel_fingerprint(key: Optional[str] = None) -> Optional[str]:
+    """
+    Get a short fingerprint for display purposes.
+    Shows first and last 4 chars with masked middle.
+    
+    Args:
+        key: Channel key (if None, reads from config)
+        
+    Returns:
+        Fingerprint like "ABCD-••••-••••-••••-••••-••••-••••-3456" or None
+        
+    Example:
+        >>> print(get_channel_fingerprint())
+        ABCD-••••-••••-••••-••••-••••-••••-3456
+    """
+    if key is None:
+        key = get_channel_key()
+    
+    if not key:
+        return None
+    
+    formatted = format_channel_key(key)
+    parts = formatted.split('-')
+    
+    # Show first and last group, mask the rest
+    masked = [parts[0]] + ['••••'] * 6 + [parts[-1]]
+    return '-'.join(masked)
+
+
+def get_channel_status() -> dict:
+    """
+    Get comprehensive channel key status.
+    
+    Returns:
+        Dictionary with:
+        - mode: 'private' or 'public'
+        - configured: bool
+        - fingerprint: masked key or None
+        - source: where key came from or None
+        - key: full key (for export) or None
+        
+    Example:
+        >>> status = get_channel_status()
+        >>> print(f"Mode: {status['mode']}")
+        Mode: private
+    """
+    key = get_channel_key()
+    
+    if key:
+        # Find which source provided the key
+        source = 'unknown'
+        env_key = os.environ.get(CHANNEL_KEY_ENV_VAR, '').strip()
+        if env_key and validate_channel_key(env_key):
+            source = 'environment'
+        else:
+            for config_path in CONFIG_LOCATIONS:
+                if config_path.exists():
+                    try:
+                        file_key = config_path.read_text().strip()
+                        if file_key and format_channel_key(file_key) == key:
+                            source = str(config_path)
+                            break
+                    except (IOError, PermissionError):
+                        continue
+        
+        return {
+            'mode': 'private',
+            'configured': True,
+            'fingerprint': get_channel_fingerprint(key),
+            'source': source,
+            'key': key,
+        }
+    else:
+        return {
+            'mode': 'public',
+            'configured': False,
+            'fingerprint': None,
+            'source': None,
+            'key': None,
+        }
+
+
+def has_channel_key() -> bool:
+    """
+    Quick check if a channel key is configured.
+    
+    Returns:
+        True if channel key is set, False for public mode
+        
+    Example:
+        >>> if has_channel_key():
+        ...     print("Private channel active")
+    """
+    return get_channel_key() is not None
+
+
+# =============================================================================
+# CLI SUPPORT
+# =============================================================================
+
+if __name__ == '__main__':
+    import sys
+    
+    def print_status():
+        """Print current channel status."""
+        status = get_channel_status()
+        print(f"Mode: {status['mode'].upper()}")
+        if status['configured']:
+            print(f"Fingerprint: {status['fingerprint']}")
+            print(f"Source: {status['source']}")
+        else:
+            print("No channel key configured (public mode)")
+    
+    if len(sys.argv) < 2:
+        print("Channel Key Manager")
+        print("=" * 40)
+        print_status()
+        print()
+        print("Commands:")
+        print("  python -m stegasoo.channel generate  - Generate new key")
+        print("  python -m stegasoo.channel set <KEY> - Set channel key")
+        print("  python -m stegasoo.channel show      - Show full key")
+        print("  python -m stegasoo.channel clear     - Remove channel key")
+        print("  python -m stegasoo.channel status    - Show status")
+        sys.exit(0)
+    
+    cmd = sys.argv[1].lower()
+    
+    if cmd == 'generate':
+        key = generate_channel_key()
+        print(f"Generated channel key:")
+        print(f"  {key}")
+        print()
+        save = input("Save to config? [y/N]: ").strip().lower()
+        if save == 'y':
+            path = set_channel_key(key)
+            print(f"Saved to: {path}")
+    
+    elif cmd == 'set':
+        if len(sys.argv) < 3:
+            print("Usage: python -m stegasoo.channel set <KEY>")
+            sys.exit(1)
+        
+        try:
+            key = sys.argv[2]
+            formatted = format_channel_key(key)
+            path = set_channel_key(formatted)
+            print(f"Channel key set: {get_channel_fingerprint(formatted)}")
+            print(f"Saved to: {path}")
+        except ValueError as e:
+            print(f"Error: {e}")
+            sys.exit(1)
+    
+    elif cmd == 'show':
+        status = get_channel_status()
+        if status['configured']:
+            print(f"Channel key: {status['key']}")
+            print(f"Source: {status['source']}")
+        else:
+            print("No channel key configured")
+    
+    elif cmd == 'clear':
+        deleted = clear_channel_key('all')
+        if deleted:
+            print(f"Removed channel key from: {', '.join(str(p) for p in deleted)}")
+        else:
+            print("No channel key files found")
+    
+    elif cmd == 'status':
+        print_status()
+    
+    else:
+        print(f"Unknown command: {cmd}")
+        sys.exit(1)

src/stegasoo/constants.py

@@ -1,8 +1,14 @@
 """
-Stegasoo Constants and Configuration
+Stegasoo Constants and Configuration (v3.2.0 - Date Independent)
 
 Central location for all magic numbers, limits, and crypto parameters.
 All version numbers, limits, and configuration values should be defined here.
+
+BREAKING CHANGES in v3.2.0:
+- Removed date dependency from cryptographic operations
+- Renamed day_phrase → passphrase throughout codebase
+- FORMAT_VERSION bumped to 4 to indicate incompatibility
+- Increased default passphrase length to compensate for removed date entropy
 """
 
 import os
@@ -12,14 +18,18 @@ from pathlib import Path
 # VERSION
 # ============================================================================
 
-__version__ = "3.1.0"
+__version__ = "3.2.0"
 
 # ============================================================================
 # FILE FORMAT
 # ============================================================================
 
 MAGIC_HEADER = b'\x89ST3'
-FORMAT_VERSION = 3
+
+# FORMAT VERSION HISTORY:
+# Version 1-3: Date-dependent encryption (v3.0.x - v3.1.x)
+# Version 4: Date-independent encryption (v3.2.0+) - BREAKING CHANGE
+FORMAT_VERSION = 4
 
 # Payload type markers
 PAYLOAD_TEXT = 0x01
@@ -46,8 +56,14 @@ PBKDF2_ITERATIONS = 600000
 # ============================================================================
 
 MAX_IMAGE_PIXELS = 24_000_000     # ~24 megapixels
+MIN_IMAGE_PIXELS = 256 * 256      # Minimum viable image size
+
 MAX_MESSAGE_SIZE = 250_000        # 250 KB (text messages)
 MAX_MESSAGE_CHARS = 250_000       # Alias for clarity in templates
+MIN_MESSAGE_LENGTH = 1            # Minimum message length
+MAX_MESSAGE_LENGTH = MAX_MESSAGE_SIZE  # Alias for consistency
+
+MAX_PAYLOAD_SIZE = MAX_MESSAGE_SIZE  # Maximum payload size (alias)
 MAX_FILENAME_LENGTH = 255         # Max filename length to store
 
 # File size limits
@@ -60,10 +76,17 @@ MIN_PIN_LENGTH = 6
 MAX_PIN_LENGTH = 9
 DEFAULT_PIN_LENGTH = 6
 
-# Phrase configuration
+# Passphrase configuration (v3.2.0: renamed from PHRASE to PASSPHRASE)
-MIN_PHRASE_WORDS = 3
+# Increased defaults to compensate for removed date entropy (~33 bits)
-MAX_PHRASE_WORDS = 12
+MIN_PASSPHRASE_WORDS = 3
-DEFAULT_PHRASE_WORDS = 3
+MAX_PASSPHRASE_WORDS = 12
+DEFAULT_PASSPHRASE_WORDS = 4  # Increased from 3 (was DEFAULT_PHRASE_WORDS)
+RECOMMENDED_PASSPHRASE_WORDS = 4  # Best practice guideline
+
+# Legacy aliases for backward compatibility during transition
+MIN_PHRASE_WORDS = MIN_PASSPHRASE_WORDS
+MAX_PHRASE_WORDS = MAX_PASSPHRASE_WORDS  
+DEFAULT_PHRASE_WORDS = DEFAULT_PASSPHRASE_WORDS
 
 # RSA configuration
 MIN_RSA_BITS = 2048
@@ -97,8 +120,11 @@ ALLOWED_KEY_EXTENSIONS = {'pem', 'key'}
 # Lossless image formats (safe for steganography)
 LOSSLESS_FORMATS = {'PNG', 'BMP', 'TIFF'}
 
+# Supported image formats for steganography
+SUPPORTED_IMAGE_FORMATS = LOSSLESS_FORMATS
+
 # ============================================================================
-# DAYS
+# DAYS (kept for organizational/UI purposes, not crypto)
 # ============================================================================
 
 DAY_NAMES = ('Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday')
@@ -184,7 +210,7 @@ def get_wordlist() -> list[str]:
 
 
 # =============================================================================
-# DCT STEGANOGRAPHY (v3.0)
+# DCT STEGANOGRAPHY (v3.0+)
 # =============================================================================
 
 # Embedding modes
@@ -200,6 +226,10 @@ DCT_STEP_SIZE = 8              # QIM quantization step
 # Valid embedding modes
 VALID_EMBED_MODES = {EMBED_MODE_LSB, EMBED_MODE_DCT}
 
+# Capacity estimation constants
+LSB_BYTES_PER_PIXEL = 3 / 8  # 3 bits per pixel (RGB, 1 bit per channel) / 8 bits per byte
+DCT_BYTES_PER_PIXEL = 0.125  # Approximate for DCT mode (varies by implementation)
+
 
 def detect_stego_mode(encrypted_data: bytes) -> str:
     """

src/stegasoo/crypto.py

@@ -1,8 +1,15 @@
 """
-Stegasoo Cryptographic Functions
+Stegasoo Cryptographic Functions (v3.2.0 - Date Independent)
 
 Key derivation, encryption, and decryption using AES-256-GCM.
 Supports both text messages and binary file payloads.
+
+BREAKING CHANGES in v3.2.0:
+- Removed date dependency from key derivation
+- Renamed day_phrase → passphrase (no daily rotation needed)
+- Messages can now be decoded without knowing encoding date
+- Enables true asynchronous communication
+- NOT backward compatible with v3.1.0 and earlier
 """
 
 import io
@@ -63,8 +70,7 @@ def hash_photo(image_data: bytes) -> bytes:
 
 def derive_hybrid_key(
     photo_data: bytes,
-    day_phrase: str,
+    passphrase: str,
-    date_str: str,
     salt: bytes,
     pin: str = "",
     rsa_key_data: Optional[bytes] = None
@@ -74,18 +80,19 @@ def derive_hybrid_key(
     
     Combines:
     - Photo hash (something you have)
-    - Day phrase (something you know, rotates daily)
+    - Passphrase (something you know)
     - PIN (something you know, static)
     - RSA key (something you have)
-    - Date (automatic rotation)
     - Salt (random per message)
     
     Uses Argon2id if available, falls back to PBKDF2.
     
+    NOTE: v3.2.0 removed date dependency and daily rotation.
+    Use a strong static passphrase instead (recommend 4+ words).
+    
     Args:
         photo_data: Reference photo bytes
-        day_phrase: The day's phrase
+        passphrase: Shared passphrase (recommend 4+ words)
-        date_str: Date string (YYYY-MM-DD)
         salt: Random salt for this message
         pin: Optional static PIN
         rsa_key_data: Optional RSA key bytes
@@ -101,9 +108,8 @@ def derive_hybrid_key(
         
         key_material = (
             photo_hash +
-            day_phrase.lower().encode() +
+            passphrase.lower().encode() +
             pin.encode() +
-            date_str.encode() +
             salt
         )
         
@@ -139,8 +145,7 @@ def derive_hybrid_key(
 
 def derive_pixel_key(
     photo_data: bytes,
-    day_phrase: str,
+    passphrase: str,
-    date_str: str,
     pin: str = "",
     rsa_key_data: Optional[bytes] = None
 ) -> bytes:
@@ -150,10 +155,11 @@ def derive_pixel_key(
     This key determines which pixels are used for embedding,
     making the message location unpredictable without the correct inputs.
     
+    NOTE: v3.2.0 removed date dependency.
+    
     Args:
         photo_data: Reference photo bytes
-        day_phrase: The day's phrase
+        passphrase: Shared passphrase
-        date_str: Date string (YYYY-MM-DD)
         pin: Optional static PIN
         rsa_key_data: Optional RSA key bytes
         
@@ -164,9 +170,8 @@ def derive_pixel_key(
     
     material = (
         photo_hash +
-        day_phrase.lower().encode() +
+        passphrase.lower().encode() +
-        pin.encode() +
+        pin.encode()
-        date_str.encode()
     )
     
     if rsa_key_data:
@@ -282,19 +287,16 @@ def _unpack_payload(data: bytes) -> DecodeResult:
 def encrypt_message(
     message: Union[str, bytes, FilePayload],
     photo_data: bytes,
-    day_phrase: str,
+    passphrase: str,
-    date_str: str,
     pin: str = "",
     rsa_key_data: Optional[bytes] = None
 ) -> bytes:
     """
     Encrypt message or file using AES-256-GCM with hybrid key derivation.
     
-    Message format:
+    Message format (v3.2.0 - no date):
     - Magic header (4 bytes)
-    - Version (1 byte)
+    - Version (1 byte) = 4
-    - Date length (1 byte)
-    - Date string (variable)
     - Salt (32 bytes)
     - IV (12 bytes)
     - Auth tag (16 bytes)
@@ -303,8 +305,7 @@ def encrypt_message(
     Args:
         message: Message string, raw bytes, or FilePayload to encrypt
         photo_data: Reference photo bytes
-        day_phrase: The day's phrase
+        passphrase: Shared passphrase (recommend 4+ words for good entropy)
-        date_str: Date string (YYYY-MM-DD)
         pin: Optional static PIN
         rsa_key_data: Optional RSA key bytes
         
@@ -316,7 +317,7 @@ def encrypt_message(
     """
     try:
         salt = secrets.token_bytes(SALT_SIZE)
-        key = derive_hybrid_key(photo_data, day_phrase, date_str, salt, pin, rsa_key_data)
+        key = derive_hybrid_key(photo_data, passphrase, salt, pin, rsa_key_data)
         iv = secrets.token_bytes(IV_SIZE)
         
         # Pack payload with type marker
@@ -335,13 +336,10 @@ def encrypt_message(
         encryptor.authenticate_additional_data(MAGIC_HEADER + bytes([FORMAT_VERSION]))
         ciphertext = encryptor.update(padded_message) + encryptor.finalize()
         
-        date_bytes = date_str.encode()
+        # v3.2.0: Simplified header without date
-        
         return (
             MAGIC_HEADER +
             bytes([FORMAT_VERSION]) +
-            bytes([len(date_bytes)]) +
-            date_bytes +
             salt +
             iv +
             encryptor.tag +
@@ -356,13 +354,16 @@ def parse_header(encrypted_data: bytes) -> Optional[dict]:
     """
     Parse the header from encrypted data.
     
+    v3.2.0: No date field in header.
+    
     Args:
         encrypted_data: Raw encrypted bytes
         
     Returns:
-        Dict with date, salt, iv, tag, ciphertext or None if invalid
+        Dict with salt, iv, tag, ciphertext or None if invalid
     """
-    if len(encrypted_data) < 10 or encrypted_data[:4] != MAGIC_HEADER:
+    # Min size: Magic(4) + Version(1) + Salt(32) + IV(12) + Tag(16) = 65 bytes
+    if len(encrypted_data) < 65 or encrypted_data[:4] != MAGIC_HEADER:
         return None
     
     try:
@@ -370,10 +371,7 @@ def parse_header(encrypted_data: bytes) -> Optional[dict]:
         if version != FORMAT_VERSION:
             return None
         
-        date_len = encrypted_data[5]
+        offset = 5
-        date_str = encrypted_data[6:6 + date_len].decode()
-        
-        offset = 6 + date_len
         salt = encrypted_data[offset:offset + SALT_SIZE]
         offset += SALT_SIZE
         iv = encrypted_data[offset:offset + IV_SIZE]
@@ -383,7 +381,6 @@ def parse_header(encrypted_data: bytes) -> Optional[dict]:
         ciphertext = encrypted_data[offset:]
         
         return {
-            'date': date_str,
             'salt': salt,
             'iv': iv,
             'tag': tag,
@@ -396,17 +393,17 @@ def parse_header(encrypted_data: bytes) -> Optional[dict]:
 def decrypt_message(
     encrypted_data: bytes,
     photo_data: bytes,
-    day_phrase: str,
+    passphrase: str,
     pin: str = "",
     rsa_key_data: Optional[bytes] = None
 ) -> DecodeResult:
     """
-    Decrypt message using the embedded date from the header.
+    Decrypt message (v3.2.0 - no date needed).
     
     Args:
         encrypted_data: Encrypted message bytes
         photo_data: Reference photo bytes
-        day_phrase: The day's phrase (must match encoding day)
+        passphrase: Shared passphrase
         pin: Optional static PIN
         rsa_key_data: Optional RSA key bytes
         
@@ -423,7 +420,7 @@ def decrypt_message(
     
     try:
         key = derive_hybrid_key(
-            photo_data, day_phrase, header['date'], header['salt'], pin, rsa_key_data
+            photo_data, passphrase, header['salt'], pin, rsa_key_data
         )
         
         cipher = Cipher(
@@ -439,20 +436,21 @@ def decrypt_message(
         
         payload_data = padded_plaintext[:original_length]
         result = _unpack_payload(payload_data)
-        result.date_encoded = header['date']
+        
+        # Note: No date_encoded field in v3.2.0
         
         return result
         
     except Exception as e:
         raise DecryptionError(
-            "Decryption failed. Check your phrase, PIN, RSA key, and reference photo."
+            "Decryption failed. Check your passphrase, PIN, RSA key, and reference photo."
         ) from e
 
 
 def decrypt_message_text(
     encrypted_data: bytes,
     photo_data: bytes,
-    day_phrase: str,
+    passphrase: str,
     pin: str = "",
     rsa_key_data: Optional[bytes] = None
 ) -> str:
@@ -464,7 +462,7 @@ def decrypt_message_text(
     Args:
         encrypted_data: Encrypted message bytes
         photo_data: Reference photo bytes
-        day_phrase: The day's phrase
+        passphrase: Shared passphrase
         pin: Optional static PIN
         rsa_key_data: Optional RSA key bytes
         
@@ -474,7 +472,7 @@ def decrypt_message_text(
     Raises:
         DecryptionError: If decryption fails or content is a file
     """
-    result = decrypt_message(encrypted_data, photo_data, day_phrase, pin, rsa_key_data)
+    result = decrypt_message(encrypted_data, photo_data, passphrase, pin, rsa_key_data)
     
     if result.is_file:
         if result.file_data:
@@ -490,22 +488,6 @@ def decrypt_message_text(
     return result.message or ""
 
 
-def get_date_from_encrypted(encrypted_data: bytes) -> Optional[str]:
-    """
-    Extract the date string from encrypted data without decrypting.
-    
-    Useful for determining which day's phrase to use.
-    
-    Args:
-        encrypted_data: Encrypted message bytes
-        
-    Returns:
-        Date string (YYYY-MM-DD) or None if invalid
-    """
-    header = parse_header(encrypted_data)
-    return header['date'] if header else None
-
-
 def has_argon2() -> bool:
     """Check if Argon2 is available."""
     return HAS_ARGON2

src/stegasoo/decode.py

@@ -0,0 +1,208 @@
+"""
+Stegasoo Decode Module (v3.2.0)
+
+High-level decoding functions for extracting messages and files from images.
+"""
+
+from typing import Optional
+from pathlib import Path
+
+from .models import DecodeInput, DecodeResult
+from .crypto import decrypt_message
+from .steganography import extract_from_image
+from .validation import (
+    require_valid_image,
+    require_security_factors,
+    require_valid_pin,
+    require_valid_rsa_key,
+)
+from .constants import EMBED_MODE_AUTO
+from .exceptions import ExtractionError, DecryptionError
+from .debug import debug
+
+
+def decode(
+    stego_image: bytes,
+    reference_photo: bytes,
+    passphrase: str,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None,
+    rsa_password: Optional[str] = None,
+    embed_mode: str = EMBED_MODE_AUTO,
+) -> DecodeResult:
+    """
+    Decode a message or file from a stego image.
+    
+    Args:
+        stego_image: Stego image bytes
+        reference_photo: Shared reference photo bytes
+        passphrase: Shared passphrase used during encoding
+        pin: Optional static PIN (if used during encoding)
+        rsa_key_data: Optional RSA key bytes (if used during encoding)
+        rsa_password: Optional RSA key password
+        embed_mode: 'auto' (default), 'lsb', or 'dct'
+        
+    Returns:
+        DecodeResult with message or file data
+        
+    Example:
+        >>> result = decode(
+        ...     stego_image=stego_bytes,
+        ...     reference_photo=ref_bytes,
+        ...     passphrase="apple forest thunder mountain",
+        ...     pin="123456"
+        ... )
+        >>> if result.is_text:
+        ...     print(result.message)
+        ... else:
+        ...     with open(result.filename, 'wb') as f:
+        ...         f.write(result.file_data)
+    """
+    debug.print(f"decode: passphrase length={len(passphrase.split())} words, "
+                f"mode={embed_mode}")
+    
+    # Validate inputs
+    require_valid_image(stego_image, "Stego image")
+    require_valid_image(reference_photo, "Reference photo")
+    require_security_factors(pin, rsa_key_data)
+    
+    if pin:
+        require_valid_pin(pin)
+    if rsa_key_data:
+        require_valid_rsa_key(rsa_key_data, rsa_password)
+    
+    # Derive pixel/coefficient selection key
+    from .crypto import derive_pixel_key
+    pixel_key = derive_pixel_key(
+        reference_photo, passphrase, pin, rsa_key_data
+    )
+    
+    # Extract encrypted data
+    encrypted = extract_from_image(
+        stego_image,
+        pixel_key,
+        embed_mode=embed_mode,
+    )
+    
+    if not encrypted:
+        debug.print("No data extracted from image")
+        raise ExtractionError("Could not extract data. Check your credentials and image.")
+    
+    debug.print(f"Extracted {len(encrypted)} bytes from image")
+    
+    # Decrypt
+    result = decrypt_message(
+        encrypted, reference_photo, passphrase, pin, rsa_key_data
+    )
+    
+    debug.print(f"Decryption successful: {result.payload_type}")
+    return result
+
+
+def decode_file(
+    stego_image: bytes,
+    reference_photo: bytes,
+    passphrase: str,
+    output_path: Optional[Path] = None,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None,
+    rsa_password: Optional[str] = None,
+    embed_mode: str = EMBED_MODE_AUTO,
+) -> Path:
+    """
+    Decode a file from a stego image and save it.
+    
+    Args:
+        stego_image: Stego image bytes
+        reference_photo: Shared reference photo bytes
+        passphrase: Shared passphrase
+        output_path: Optional output path (defaults to original filename)
+        pin: Optional static PIN
+        rsa_key_data: Optional RSA key bytes
+        rsa_password: Optional RSA key password
+        embed_mode: 'auto', 'lsb', or 'dct'
+        
+    Returns:
+        Path where file was saved
+        
+    Raises:
+        DecryptionError: If payload is text, not a file
+    """
+    result = decode(
+        stego_image,
+        reference_photo,
+        passphrase,
+        pin,
+        rsa_key_data,
+        rsa_password,
+        embed_mode,
+    )
+    
+    if not result.is_file:
+        raise DecryptionError("Payload is a text message, not a file")
+    
+    if output_path is None:
+        output_path = Path(result.filename or "extracted_file")
+    else:
+        output_path = Path(output_path)
+        if output_path.is_dir():
+            output_path = output_path / (result.filename or "extracted_file")
+    
+    # Write file
+    output_path.write_bytes(result.file_data or b"")
+    
+    debug.print(f"File saved to: {output_path}")
+    return output_path
+
+
+def decode_text(
+    stego_image: bytes,
+    reference_photo: bytes,
+    passphrase: str,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None,
+    rsa_password: Optional[str] = None,
+    embed_mode: str = EMBED_MODE_AUTO,
+) -> str:
+    """
+    Decode a text message from a stego image.
+    
+    Convenience function that returns just the message string.
+    
+    Args:
+        stego_image: Stego image bytes
+        reference_photo: Shared reference photo bytes
+        passphrase: Shared passphrase
+        pin: Optional static PIN
+        rsa_key_data: Optional RSA key bytes
+        rsa_password: Optional RSA key password
+        embed_mode: 'auto', 'lsb', or 'dct'
+        
+    Returns:
+        Decoded message string
+        
+    Raises:
+        DecryptionError: If payload is a file, not text
+    """
+    result = decode(
+        stego_image,
+        reference_photo,
+        passphrase,
+        pin,
+        rsa_key_data,
+        rsa_password,
+        embed_mode,
+    )
+    
+    if result.is_file:
+        # Try to decode as text
+        if result.file_data:
+            try:
+                return result.file_data.decode('utf-8')
+            except UnicodeDecodeError:
+                raise DecryptionError(
+                    f"Payload is a binary file ({result.filename or 'unnamed'}), not text"
+                )
+        return ""
+    
+    return result.message or ""

src/stegasoo/encode.py

@@ -0,0 +1,234 @@
+"""
+Stegasoo Encode Module (v3.2.0)
+
+High-level encoding functions for hiding messages and files in images.
+"""
+
+from typing import Optional, Union
+from pathlib import Path
+
+from .models import EncodeInput, EncodeResult, FilePayload
+from .crypto import encrypt_message, derive_pixel_key
+from .steganography import embed_in_image
+from .validation import (
+    require_valid_payload,
+    require_valid_image,
+    require_security_factors,
+    require_valid_pin,
+    require_valid_rsa_key,
+)
+from .utils import generate_filename
+from .constants import EMBED_MODE_LSB
+from .debug import debug
+
+
+def encode(
+    message: Union[str, bytes, FilePayload],
+    reference_photo: bytes,
+    carrier_image: bytes,
+    passphrase: str,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None,
+    rsa_password: Optional[str] = None,
+    output_format: Optional[str] = None,
+    embed_mode: str = EMBED_MODE_LSB,
+    dct_output_format: str = "png",
+    dct_color_mode: str = "grayscale",
+) -> EncodeResult:
+    """
+    Encode a message or file into an image.
+    
+    Args:
+        message: Text message, raw bytes, or FilePayload to hide
+        reference_photo: Shared reference photo bytes
+        carrier_image: Carrier image bytes
+        passphrase: Shared passphrase (recommend 4+ words)
+        pin: Optional static PIN
+        rsa_key_data: Optional RSA private key PEM bytes
+        rsa_password: Optional password for encrypted RSA key
+        output_format: Force output format ('PNG', 'BMP') - LSB mode only
+        embed_mode: 'lsb' (default) or 'dct'
+        dct_output_format: For DCT mode - 'png' or 'jpeg'
+        dct_color_mode: For DCT mode - 'grayscale' or 'color'
+        
+    Returns:
+        EncodeResult with stego image and metadata
+        
+    Example:
+        >>> result = encode(
+        ...     message="Secret message",
+        ...     reference_photo=ref_bytes,
+        ...     carrier_image=carrier_bytes,
+        ...     passphrase="apple forest thunder mountain",
+        ...     pin="123456"
+        ... )
+        >>> with open('stego.png', 'wb') as f:
+        ...     f.write(result.stego_image)
+    """
+    debug.print(f"encode: passphrase length={len(passphrase.split())} words, "
+                f"pin={'set' if pin else 'none'}, mode={embed_mode}")
+    
+    # Validate inputs
+    require_valid_payload(message)
+    require_valid_image(reference_photo, "Reference photo")
+    require_valid_image(carrier_image, "Carrier image")
+    require_security_factors(pin, rsa_key_data)
+    
+    if pin:
+        require_valid_pin(pin)
+    if rsa_key_data:
+        require_valid_rsa_key(rsa_key_data, rsa_password)
+    
+    # Encrypt message
+    encrypted = encrypt_message(
+        message, reference_photo, passphrase, pin, rsa_key_data
+    )
+    
+    debug.print(f"Encrypted payload: {len(encrypted)} bytes")
+    
+    # Derive pixel/coefficient selection key
+    pixel_key = derive_pixel_key(
+        reference_photo, passphrase, pin, rsa_key_data
+    )
+    
+    # Embed in image
+    stego_data, stats, extension = embed_in_image(
+        encrypted,
+        carrier_image,
+        pixel_key,
+        output_format=output_format,
+        embed_mode=embed_mode,
+        dct_output_format=dct_output_format,
+        dct_color_mode=dct_color_mode,
+    )
+    
+    # Generate filename
+    filename = generate_filename(extension=extension)
+    
+    # Create result
+    if hasattr(stats, 'pixels_modified'):
+        # LSB mode stats
+        return EncodeResult(
+            stego_image=stego_data,
+            filename=filename,
+            pixels_modified=stats.pixels_modified,
+            total_pixels=stats.total_pixels,
+            capacity_used=stats.capacity_used,
+            date_used=None,  # No longer used in v3.2.0
+        )
+    else:
+        # DCT mode stats
+        return EncodeResult(
+            stego_image=stego_data,
+            filename=filename,
+            pixels_modified=stats.blocks_used * 64,
+            total_pixels=stats.blocks_available * 64,
+            capacity_used=stats.usage_percent / 100.0,
+            date_used=None,
+        )
+
+
+def encode_file(
+    filepath: Union[str, Path],
+    reference_photo: bytes,
+    carrier_image: bytes,
+    passphrase: str,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None,
+    rsa_password: Optional[str] = None,
+    output_format: Optional[str] = None,
+    filename_override: Optional[str] = None,
+    embed_mode: str = EMBED_MODE_LSB,
+    dct_output_format: str = "png",
+    dct_color_mode: str = "grayscale",
+) -> EncodeResult:
+    """
+    Encode a file into an image.
+    
+    Convenience wrapper that loads a file and encodes it.
+    
+    Args:
+        filepath: Path to file to embed
+        reference_photo: Shared reference photo bytes
+        carrier_image: Carrier image bytes
+        passphrase: Shared passphrase
+        pin: Optional static PIN
+        rsa_key_data: Optional RSA key bytes
+        rsa_password: Optional RSA key password
+        output_format: Force output format - LSB only
+        filename_override: Override stored filename
+        embed_mode: 'lsb' or 'dct'
+        dct_output_format: 'png' or 'jpeg'
+        dct_color_mode: 'grayscale' or 'color'
+        
+    Returns:
+        EncodeResult
+    """
+    payload = FilePayload.from_file(str(filepath), filename_override)
+    
+    return encode(
+        message=payload,
+        reference_photo=reference_photo,
+        carrier_image=carrier_image,
+        passphrase=passphrase,
+        pin=pin,
+        rsa_key_data=rsa_key_data,
+        rsa_password=rsa_password,
+        output_format=output_format,
+        embed_mode=embed_mode,
+        dct_output_format=dct_output_format,
+        dct_color_mode=dct_color_mode,
+    )
+
+
+def encode_bytes(
+    data: bytes,
+    filename: str,
+    reference_photo: bytes,
+    carrier_image: bytes,
+    passphrase: str,
+    pin: str = "",
+    rsa_key_data: Optional[bytes] = None,
+    rsa_password: Optional[str] = None,
+    output_format: Optional[str] = None,
+    mime_type: Optional[str] = None,
+    embed_mode: str = EMBED_MODE_LSB,
+    dct_output_format: str = "png",
+    dct_color_mode: str = "grayscale",
+) -> EncodeResult:
+    """
+    Encode raw bytes with metadata into an image.
+    
+    Args:
+        data: Raw bytes to embed
+        filename: Filename to associate with data
+        reference_photo: Shared reference photo bytes
+        carrier_image: Carrier image bytes
+        passphrase: Shared passphrase
+        pin: Optional static PIN
+        rsa_key_data: Optional RSA key bytes
+        rsa_password: Optional RSA key password
+        output_format: Force output format - LSB only
+        mime_type: MIME type of data
+        embed_mode: 'lsb' or 'dct'
+        dct_output_format: 'png' or 'jpeg'
+        dct_color_mode: 'grayscale' or 'color'
+        
+    Returns:
+        EncodeResult
+    """
+    payload = FilePayload(data=data, filename=filename, mime_type=mime_type)
+    
+    return encode(
+        message=payload,
+        reference_photo=reference_photo,
+        carrier_image=carrier_image,
+        passphrase=passphrase,
+        pin=pin,
+        rsa_key_data=rsa_key_data,
+        rsa_password=rsa_password,
+        output_format=output_format,
+        embed_mode=embed_mode,
+        dct_output_format=dct_output_format,
+        dct_color_mode=dct_color_mode,
+    )

src/stegasoo/generate.py

@@ -0,0 +1,167 @@
+"""
+Stegasoo Generate Module (v3.2.0)
+
+Public API for generating credentials (PINs, passphrases, RSA keys).
+"""
+
+from typing import Optional
+
+from .keygen import (
+    generate_pin as _generate_pin,
+    generate_phrase,
+    generate_rsa_key as _generate_rsa_key,
+    export_rsa_key_pem,
+    load_rsa_key,
+)
+from .models import Credentials
+from .constants import (
+    DEFAULT_PIN_LENGTH,
+    DEFAULT_PASSPHRASE_WORDS,
+    DEFAULT_RSA_BITS,
+)
+from .debug import debug
+
+
+# Re-export from keygen for convenience
+__all__ = [
+    'generate_pin',
+    'generate_passphrase', 
+    'generate_rsa_key',
+    'generate_credentials',
+    'export_rsa_key_pem',
+    'load_rsa_key',
+]
+
+
+def generate_pin(length: int = DEFAULT_PIN_LENGTH) -> str:
+    """
+    Generate a random PIN.
+    
+    PINs never start with zero for usability.
+    
+    Args:
+        length: PIN length (6-9 digits, default 6)
+        
+    Returns:
+        PIN string
+        
+    Example:
+        >>> pin = generate_pin()
+        >>> len(pin)
+        6
+        >>> pin[0] != '0'
+        True
+    """
+    return _generate_pin(length)
+
+
+def generate_passphrase(words: int = DEFAULT_PASSPHRASE_WORDS) -> str:
+    """
+    Generate a random passphrase from BIP-39 wordlist.
+    
+    In v3.2.0, this generates a single passphrase (not daily phrases).
+    Default is 4 words for good security (increased from 3 in v3.1.0).
+    
+    Args:
+        words: Number of words (3-12, default 4)
+        
+    Returns:
+        Space-separated passphrase
+        
+    Example:
+        >>> passphrase = generate_passphrase(4)
+        >>> len(passphrase.split())
+        4
+    """
+    return generate_phrase(words)
+
+
+def generate_rsa_key(
+    bits: int = DEFAULT_RSA_BITS,
+    password: Optional[str] = None
+) -> str:
+    """
+    Generate an RSA private key in PEM format.
+    
+    Args:
+        bits: Key size (2048, 3072, or 4096, default 2048)
+        password: Optional password to encrypt the key
+        
+    Returns:
+        PEM-encoded key string
+        
+    Example:
+        >>> key_pem = generate_rsa_key(2048)
+        >>> '-----BEGIN PRIVATE KEY-----' in key_pem
+        True
+    """
+    key_obj = _generate_rsa_key(bits)
+    pem_bytes = export_rsa_key_pem(key_obj, password)
+    return pem_bytes.decode('utf-8')
+
+
+def generate_credentials(
+    use_pin: bool = True,
+    use_rsa: bool = False,
+    pin_length: int = DEFAULT_PIN_LENGTH,
+    rsa_bits: int = DEFAULT_RSA_BITS,
+    passphrase_words: int = DEFAULT_PASSPHRASE_WORDS,
+    rsa_password: Optional[str] = None,
+) -> Credentials:
+    """
+    Generate a complete set of credentials.
+    
+    In v3.2.0, this generates a single passphrase (not daily phrases).
+    At least one of use_pin or use_rsa must be True.
+    
+    Args:
+        use_pin: Whether to generate a PIN
+        use_rsa: Whether to generate an RSA key
+        pin_length: PIN length (default 6)
+        rsa_bits: RSA key size (default 2048)
+        passphrase_words: Number of words in passphrase (default 4)
+        rsa_password: Optional password for RSA key
+        
+    Returns:
+        Credentials object with passphrase, PIN, and/or RSA key
+        
+    Raises:
+        ValueError: If neither PIN nor RSA is selected
+        
+    Example:
+        >>> creds = generate_credentials(use_pin=True, use_rsa=False)
+        >>> len(creds.passphrase.split())
+        4
+        >>> len(creds.pin)
+        6
+    """
+    if not use_pin and not use_rsa:
+        raise ValueError("Must select at least one security factor (PIN or RSA key)")
+    
+    debug.print(f"Generating credentials: PIN={use_pin}, RSA={use_rsa}, "
+                f"passphrase_words={passphrase_words}")
+    
+    # Generate passphrase (single, not daily)
+    passphrase = generate_phrase(passphrase_words)
+    
+    # Generate PIN if requested
+    pin = _generate_pin(pin_length) if use_pin else None
+    
+    # Generate RSA key if requested
+    rsa_key_pem = None
+    if use_rsa:
+        rsa_key_obj = _generate_rsa_key(rsa_bits)
+        rsa_key_bytes = export_rsa_key_pem(rsa_key_obj, rsa_password)
+        rsa_key_pem = rsa_key_bytes.decode('utf-8')
+    
+    # Create Credentials object (v3.2.0 format)
+    creds = Credentials(
+        passphrase=passphrase,
+        pin=pin,
+        rsa_key_pem=rsa_key_pem,
+        rsa_bits=rsa_bits if use_rsa else None,
+        words_per_passphrase=passphrase_words,
+    )
+    
+    debug.print(f"Credentials generated: {creds.total_entropy} bits total entropy")
+    return creds

src/stegasoo/image_utils.py

@@ -0,0 +1,166 @@
+"""
+Stegasoo Image Utilities (v3.2.0)
+
+Functions for analyzing images and comparing capacity.
+"""
+
+from typing import Optional
+import io
+from PIL import Image
+
+from .models import ImageInfo, CapacityComparison
+from .steganography import calculate_capacity, has_dct_support
+from .constants import EMBED_MODE_LSB, EMBED_MODE_DCT
+from .debug import debug
+
+
+def get_image_info(image_data: bytes) -> ImageInfo:
+    """
+    Get detailed information about an image.
+    
+    Args:
+        image_data: Image file bytes
+        
+    Returns:
+        ImageInfo with dimensions, format, capacity estimates
+        
+    Example:
+        >>> info = get_image_info(carrier_bytes)
+        >>> print(f"{info.width}x{info.height}, {info.lsb_capacity_kb} KB capacity")
+    """
+    img = Image.open(io.BytesIO(image_data))
+    
+    width, height = img.size
+    pixels = width * height
+    format_str = img.format or "Unknown"
+    mode = img.mode
+    
+    # Calculate LSB capacity
+    lsb_capacity = calculate_capacity(image_data, bits_per_channel=1)
+    
+    # Calculate DCT capacity if available
+    dct_capacity = None
+    if has_dct_support():
+        try:
+            from .dct_steganography import calculate_dct_capacity
+            dct_info = calculate_dct_capacity(image_data)
+            dct_capacity = dct_info.usable_capacity_bytes
+        except Exception as e:
+            debug.print(f"Could not calculate DCT capacity: {e}")
+    
+    info = ImageInfo(
+        width=width,
+        height=height,
+        pixels=pixels,
+        format=format_str,
+        mode=mode,
+        file_size=len(image_data),
+        lsb_capacity_bytes=lsb_capacity,
+        lsb_capacity_kb=lsb_capacity / 1024,
+        dct_capacity_bytes=dct_capacity,
+        dct_capacity_kb=dct_capacity / 1024 if dct_capacity else None,
+    )
+    
+    debug.print(f"Image info: {width}x{height}, LSB={lsb_capacity} bytes, "
+                f"DCT={dct_capacity or 'N/A'} bytes")
+    
+    return info
+
+
+def compare_capacity(
+    carrier_image: bytes,
+    reference_photo: Optional[bytes] = None,
+) -> CapacityComparison:
+    """
+    Compare embedding capacity between LSB and DCT modes.
+    
+    Args:
+        carrier_image: Carrier image bytes
+        reference_photo: Optional reference photo (not used in v3.2.0, kept for API compatibility)
+        
+    Returns:
+        CapacityComparison with capacity info for both modes
+        
+    Example:
+        >>> comparison = compare_capacity(carrier_bytes)
+        >>> print(f"LSB: {comparison.lsb_kb:.1f} KB")
+        >>> print(f"DCT: {comparison.dct_kb:.1f} KB")
+    """
+    img = Image.open(io.BytesIO(carrier_image))
+    width, height = img.size
+    
+    # LSB capacity
+    lsb_bytes = calculate_capacity(carrier_image, bits_per_channel=1)
+    lsb_kb = lsb_bytes / 1024
+    
+    # DCT capacity
+    dct_available = has_dct_support()
+    dct_bytes = None
+    dct_kb = None
+    
+    if dct_available:
+        try:
+            from .dct_steganography import calculate_dct_capacity
+            dct_info = calculate_dct_capacity(carrier_image)
+            dct_bytes = dct_info.usable_capacity_bytes
+            dct_kb = dct_bytes / 1024
+        except Exception as e:
+            debug.print(f"DCT capacity calculation failed: {e}")
+            dct_available = False
+    
+    comparison = CapacityComparison(
+        image_width=width,
+        image_height=height,
+        lsb_available=True,
+        lsb_bytes=lsb_bytes,
+        lsb_kb=lsb_kb,
+        lsb_output_format="PNG/BMP (color)",
+        dct_available=dct_available,
+        dct_bytes=dct_bytes,
+        dct_kb=dct_kb,
+        dct_output_formats=["PNG (grayscale)", "JPEG (grayscale)"] if dct_available else None,
+        dct_ratio_vs_lsb=(dct_bytes / lsb_bytes * 100) if dct_bytes else None,
+    )
+    
+    debug.print(f"Capacity comparison: LSB={lsb_kb:.1f}KB, DCT={dct_kb or 'N/A'}KB")
+    
+    return comparison
+
+
+def validate_carrier_capacity(
+    carrier_image: bytes,
+    payload_size: int,
+    embed_mode: str = EMBED_MODE_LSB,
+) -> dict:
+    """
+    Check if a payload will fit in a carrier image.
+    
+    Args:
+        carrier_image: Carrier image bytes
+        payload_size: Size of payload in bytes
+        embed_mode: 'lsb' or 'dct'
+        
+    Returns:
+        Dict with 'fits', 'capacity', 'usage_percent', 'headroom'
+    """
+    from .steganography import calculate_capacity_by_mode
+    
+    capacity_info = calculate_capacity_by_mode(carrier_image, embed_mode)
+    capacity = capacity_info['capacity_bytes']
+    
+    # Add encryption overhead estimate
+    estimated_size = payload_size + 200  # Approximate overhead
+    
+    fits = estimated_size <= capacity
+    usage_percent = (estimated_size / capacity * 100) if capacity > 0 else 100.0
+    headroom = capacity - estimated_size
+    
+    return {
+        'fits': fits,
+        'capacity': capacity,
+        'payload_size': payload_size,
+        'estimated_size': estimated_size,
+        'usage_percent': min(usage_percent, 100.0),
+        'headroom': headroom,
+        'mode': embed_mode,
+    }

src/stegasoo/models.py

@@ -1,27 +1,41 @@
 """
-Stegasoo Data Models
+Stegasoo Data Models (v3.2.0)
 
 Dataclasses for structured data exchange between modules and frontends.
+
+Changes in v3.2.0:
+- Renamed day_phrase → passphrase
+- Credentials now uses single passphrase instead of day mapping
+- Removed date_str from EncodeInput (date no longer used in crypto)
+- Made date_used optional in EncodeResult (cosmetic only)
+- Added ImageInfo, CapacityComparison, GenerateResult
 """
 
 from dataclasses import dataclass, field
 from datetime import date
-from typing import Optional, Union
+from typing import Optional, Union, List
 
 
 @dataclass
 class Credentials:
-    """Generated credentials for encoding/decoding."""
+    """
-    phrases: dict[str, str]  # Day -> phrase mapping
+    Generated credentials for encoding/decoding.
+    
+    v3.2.0: Simplified to use single passphrase instead of daily rotation.
+    """
+    passphrase: str  # Single passphrase (no daily rotation)
     pin: Optional[str] = None
     rsa_key_pem: Optional[str] = None
     rsa_bits: Optional[int] = None
-    words_per_phrase: int = 3
+    words_per_passphrase: int = 4  # Increased from 3 in v3.1.0
+    
+    # Optional: backup passphrases for multi-factor or rotation
+    backup_passphrases: Optional[list[str]] = None
     
     @property
-    def phrase_entropy(self) -> int:
+    def passphrase_entropy(self) -> int:
-        """Entropy in bits from phrases (~11 bits per BIP-39 word)."""
+        """Entropy in bits from passphrase (~11 bits per BIP-39 word)."""
-        return self.words_per_phrase * 11
+        return self.words_per_passphrase * 11
     
     @property
     def pin_entropy(self) -> int:
@@ -40,7 +54,13 @@ class Credentials:
     @property
     def total_entropy(self) -> int:
         """Total entropy in bits (excluding reference photo)."""
-        return self.phrase_entropy + self.pin_entropy + self.rsa_entropy
+        return self.passphrase_entropy + self.pin_entropy + self.rsa_entropy
+    
+    # Legacy property for compatibility
+    @property
+    def phrase_entropy(self) -> int:
+        """Alias for passphrase_entropy (backward compatibility)."""
+        return self.passphrase_entropy
 
 
 @dataclass
@@ -70,30 +90,33 @@ class FilePayload:
 
 @dataclass
 class EncodeInput:
-    """Input parameters for encoding a message."""
+    """
+    Input parameters for encoding a message.
+    
+    v3.2.0: Removed date_str (date no longer used in crypto).
+    """
     message: Union[str, bytes, FilePayload]  # Text, raw bytes, or file
     reference_photo: bytes
     carrier_image: bytes
-    day_phrase: str
+    passphrase: str  # Renamed from day_phrase
     pin: str = ""
     rsa_key_data: Optional[bytes] = None
     rsa_password: Optional[str] = None
-    date_str: Optional[str] = None  # YYYY-MM-DD, defaults to today
-    
-    def __post_init__(self):
-        if self.date_str is None:
-            self.date_str = date.today().isoformat()
 
 
 @dataclass
 class EncodeResult:
-    """Result of encoding operation."""
+    """
+    Result of encoding operation.
+    
+    v3.2.0: date_used is now optional/cosmetic (not used in crypto).
+    """
     stego_image: bytes
     filename: str
     pixels_modified: int
     total_pixels: int
     capacity_used: float  # 0.0 - 1.0
-    date_used: str
+    date_used: Optional[str] = None  # Cosmetic only (for filename organization)
     
     @property
     def capacity_percent(self) -> float:
@@ -103,10 +126,14 @@ class EncodeResult:
 
 @dataclass
 class DecodeInput:
-    """Input parameters for decoding a message."""
+    """
+    Input parameters for decoding a message.
+    
+    v3.2.0: Renamed day_phrase → passphrase, no date needed.
+    """
     stego_image: bytes
     reference_photo: bytes
-    day_phrase: str
+    passphrase: str  # Renamed from day_phrase
     pin: str = ""
     rsa_key_data: Optional[bytes] = None
     rsa_password: Optional[str] = None
@@ -114,13 +141,17 @@ class DecodeInput:
 
 @dataclass
 class DecodeResult:
-    """Result of decoding operation."""
+    """
+    Result of decoding operation.
+    
+    v3.2.0: date_encoded is always None (date removed from crypto).
+    """
     payload_type: str  # 'text' or 'file'
     message: Optional[str] = None  # For text payloads
     file_data: Optional[bytes] = None  # For file payloads
     filename: Optional[str] = None  # Original filename for file payloads
     mime_type: Optional[str] = None  # MIME type hint
-    date_encoded: Optional[str] = None
+    date_encoded: Optional[str] = None  # Always None in v3.2.0 (kept for compatibility)
     
     @property
     def is_file(self) -> bool:
@@ -165,13 +196,77 @@ class ValidationResult:
     is_valid: bool
     error_message: str = ""
     details: dict = field(default_factory=dict)
+    warning: Optional[str] = None  # v3.2.0: Added for passphrase length warnings
     
     @classmethod
-    def ok(cls, **details) -> 'ValidationResult':
+    def ok(cls, warning: Optional[str] = None, **details) -> 'ValidationResult':
         """Create a successful validation result."""
-        return cls(is_valid=True, details=details)
+        result = cls(is_valid=True, details=details)
+        if warning:
+            result.warning = warning
+        return result
     
     @classmethod
     def error(cls, message: str, **details) -> 'ValidationResult':
         """Create a failed validation result."""
         return cls(is_valid=False, error_message=message, details=details)
+
+
+# =============================================================================
+# NEW MODELS FOR V3.2.0 PUBLIC API
+# =============================================================================
+
+@dataclass
+class ImageInfo:
+    """Information about an image for steganography."""
+    width: int
+    height: int
+    pixels: int
+    format: str
+    mode: str
+    file_size: int
+    lsb_capacity_bytes: int
+    lsb_capacity_kb: float
+    dct_capacity_bytes: Optional[int] = None
+    dct_capacity_kb: Optional[float] = None
+
+
+@dataclass
+class CapacityComparison:
+    """Comparison of embedding capacity between modes."""
+    image_width: int
+    image_height: int
+    lsb_available: bool
+    lsb_bytes: int
+    lsb_kb: float
+    lsb_output_format: str
+    dct_available: bool
+    dct_bytes: Optional[int] = None
+    dct_kb: Optional[float] = None
+    dct_output_formats: Optional[List[str]] = None
+    dct_ratio_vs_lsb: Optional[float] = None
+
+
+@dataclass
+class GenerateResult:
+    """Result of credential generation."""
+    passphrase: str
+    pin: Optional[str] = None
+    rsa_key_pem: Optional[str] = None
+    passphrase_words: int = 4
+    passphrase_entropy: int = 0
+    pin_entropy: int = 0
+    rsa_entropy: int = 0
+    total_entropy: int = 0
+    
+    def __str__(self) -> str:
+        lines = [
+            "Generated Credentials:",
+            f"  Passphrase: {self.passphrase}",
+        ]
+        if self.pin:
+            lines.append(f"  PIN: {self.pin}")
+        if self.rsa_key_pem:
+            lines.append(f"  RSA Key: {len(self.rsa_key_pem)} bytes PEM")
+        lines.append(f"  Total Entropy: {self.total_entropy} bits")
+        return "\n".join(lines)

src/stegasoo/validation.py

@@ -1,7 +1,12 @@
 """
-Stegasoo Input Validation
+Stegasoo Input Validation (v3.2.0)
 
 Validators for all user inputs with clear error messages.
+
+Changes in v3.2.0:
+- Renamed validate_phrase() → validate_passphrase()
+- Added word count validation with warnings for passphrases
+- Added validators for embed modes and DCT parameters
 """
 
 import io
@@ -14,6 +19,8 @@ from .constants import (
     MAX_MESSAGE_SIZE, MAX_FILE_PAYLOAD_SIZE, MAX_IMAGE_PIXELS, MAX_FILE_SIZE,
     MIN_RSA_BITS, MIN_KEY_PASSWORD_LENGTH,
     ALLOWED_IMAGE_EXTENSIONS, ALLOWED_KEY_EXTENSIONS,
+    MIN_PASSPHRASE_WORDS, RECOMMENDED_PASSPHRASE_WORDS,
+    EMBED_MODE_LSB, EMBED_MODE_DCT, EMBED_MODE_AUTO,
 )
 from .models import ValidationResult, FilePayload
 from .exceptions import (
@@ -325,55 +332,110 @@ def validate_key_password(password: str) -> ValidationResult:
     return ValidationResult.ok(length=len(password))
 
 
-def validate_phrase(phrase: str) -> ValidationResult:
+def validate_passphrase(passphrase: str) -> ValidationResult:
     """
-    Validate day phrase.
+    Validate passphrase.
+    
+    v3.2.0: Recommend 4+ words for good entropy (since date is no longer used).
     
     Args:
-        phrase: Phrase string
+        passphrase: Passphrase string
         
     Returns:
-        ValidationResult with word_count
+        ValidationResult with word_count and optional warning
     """
-    if not phrase or not phrase.strip():
+    if not passphrase or not passphrase.strip():
-        return ValidationResult.error("Day phrase is required")
+        return ValidationResult.error("Passphrase is required")
     
-    words = phrase.strip().split()
+    words = passphrase.strip().split()
+    
+    if len(words) < MIN_PASSPHRASE_WORDS:
+        return ValidationResult.error(
+            f"Passphrase should have at least {MIN_PASSPHRASE_WORDS} words"
+        )
+    
+    # Provide warning if below recommended length
+    if len(words) < RECOMMENDED_PASSPHRASE_WORDS:
+        return ValidationResult.ok(
+            word_count=len(words),
+            warning=f"Recommend {RECOMMENDED_PASSPHRASE_WORDS}+ words for better security"
+        )
     
     return ValidationResult.ok(word_count=len(words))
 
 
-def validate_date_string(date_str: str) -> ValidationResult:
+# =============================================================================
+# NEW VALIDATORS FOR V3.2.0
+# =============================================================================
+
+def validate_reference_photo(photo_data: bytes) -> ValidationResult:
+    """Validate reference photo. Alias for validate_image."""
+    return validate_image(photo_data, "Reference photo")
+
+
+def validate_carrier(carrier_data: bytes) -> ValidationResult:
+    """Validate carrier image. Alias for validate_image."""
+    return validate_image(carrier_data, "Carrier image")
+
+
+def validate_embed_mode(mode: str) -> ValidationResult:
     """
-    Validate date string format (YYYY-MM-DD).
+    Validate embedding mode.
     
     Args:
-        date_str: Date string
+        mode: Embedding mode string
         
     Returns:
         ValidationResult
     """
-    if not date_str:
+    valid_modes = {EMBED_MODE_LSB, EMBED_MODE_DCT, EMBED_MODE_AUTO}
-        return ValidationResult.error("Date is required")
     
-    if len(date_str) != 10:
+    if mode not in valid_modes:
-        return ValidationResult.error("Date must be in YYYY-MM-DD format")
+        return ValidationResult.error(
+            f"Invalid embed_mode: '{mode}'. Valid options: {', '.join(sorted(valid_modes))}"
+        )
     
-    if date_str[4] != '-' or date_str[7] != '-':
+    return ValidationResult.ok(mode=mode)
-        return ValidationResult.error("Date must be in YYYY-MM-DD format")
 
-    try:
-        year = int(date_str[0:4])
-        month = int(date_str[5:7])
-        day = int(date_str[8:10])
 
-        if not (1 <= month <= 12 and 1 <= day <= 31 and 2000 <= year <= 2100):
+def validate_dct_output_format(format_str: str) -> ValidationResult:
-            return ValidationResult.error("Invalid date values")
+    """
+    Validate DCT output format.
     
-        return ValidationResult.ok(year=year, month=month, day=day)
+    Args:
+        format_str: Output format ('png' or 'jpeg')
         
-    except ValueError:
+    Returns:
-        return ValidationResult.error("Date must contain valid numbers")
+        ValidationResult
+    """
+    valid_formats = {'png', 'jpeg'}
+    
+    if format_str.lower() not in valid_formats:
+        return ValidationResult.error(
+            f"Invalid DCT output format: '{format_str}'. Valid options: {', '.join(sorted(valid_formats))}"
+        )
+    
+    return ValidationResult.ok(format=format_str.lower())
+
+
+def validate_dct_color_mode(mode: str) -> ValidationResult:
+    """
+    Validate DCT color mode.
+    
+    Args:
+        mode: Color mode ('grayscale' or 'color')
+        
+    Returns:
+        ValidationResult
+    """
+    valid_modes = {'grayscale', 'color'}
+    
+    if mode.lower() not in valid_modes:
+        return ValidationResult.error(
+            f"Invalid DCT color mode: '{mode}'. Valid options: {', '.join(sorted(valid_modes))}"
+        )
+    
+    return ValidationResult.ok(mode=mode.lower())
 
 
 # ============================================================================