Implement two audio embedding modes following the same multi-factor authentication pipeline as image steganography (passphrase + PIN + optional RSA key + optional channel key): - audio_lsb: High-capacity LSB embedding in PCM samples for lossless formats (WAV/FLAC). Uses ChaCha20-keyed sample index selection. - audio_spread: Direct-sequence spread spectrum (DSSS) with ChaCha20- keyed bipolar chip codes, Reed-Solomon error correction, and 3-copy majority-voted length headers. Designed to survive lossy compression. New files: - audio_steganography.py: LSB embed/extract on PCM samples - spread_steganography.py: Spread spectrum embed/extract - audio_utils.py: Format detection, transcoding, validation helpers - tests/test_audio.py: 22 tests covering both modes end-to-end Updated encode.py, decode.py, cli.py (audio-encode/audio-decode commands), constants.py, models.py, exceptions.py, validation.py, __init__.py, and pyproject.toml ([audio] extra). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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3.8 KiB