Audio Signal Authentication and Integrity Protection

This paper presents SAIN (Signal Authentication and INtegrity), an improvement to an algorithm developed for the fragile watermarking of audio files, composed of sequences of samples, with the purpose of integrity protection. First of all, the original method based on cryptographic hash functions is made secure with the use of Message Authentication Codes (MACs). Secondly, the quantity of security data is reduced, also thanks to the use of MACs, decreasing the number of original least significant bits that could potentially be modified by the embedding of the watermark, and therefore improving the quality. Finally, the localization ability is also improved by making the block size an input parameter of the algorithm.