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Abstract:Advances in speech synthesis have made voice cloning inexpensive and convincing, and fraud built on synthetic audio is now a practical concern. Embedding verifiable information directly in an audio signal is one response to this problem. This paper revisits phase coding, a classical audio steganography method that modifies the phase spectrum of a carrier. Traditional phase coding places the entire payload in the first segment of the signal and propagates the resulting phase difference through the remaining segments, which limits capacity and degrades audio quality. We describe a segment-distributed variant that spreads the payload across every segment and updates each segment independently, and we pair it with a framing layer that adds a synchronization word, a length field, a CRC-16 checksum, and Hamming(7,4) error correction. We identify and correct a quantization defect that causes the method to fail on speech, where a magnitude floor referenced to the whole signal is required for the embedded phase to survive conversion to 16-bit samples. Measured over four carriers, including real speech, the method recovers every message on a clean channel while the classical baseline recovers none of the speech messages, and it improves the stego signal-to-noise ratio by approximately 24 dB. Usable capacity rises from 1023 bits to 32768 bits on a five second carrier at equivalent embedding time. Under amplitude scaling and moderate requantization the framing layer raises message recovery from 75% to 100%. We also report the limits of the method. Because the payload occupies a narrow band below the Nyquist frequency, it does not survive lossy compression, resampling, or broadband additive noise, and the fixed bin placement offers no resistance to a blind detector. We state these boundaries explicitly and outline keyed bin selection as the path to addressing them.

Submission history

From: Guang Yang [view email]
[v1] Wed, 21 Aug 2024 19:25:31 UTC (546 KB)
[v2] Tue, 27 Aug 2024 06:58:34 UTC (549 KB)
[v3] Sun, 9 Aug 2026 21:27:15 UTC (239 KB)