Security of robust audio hashes

Robust hash algorithms can be used as tools for identifying or discriminating content, e.g. for automated tracking systems and filters for file sharing networks. When they are used in security relevant applications, such as in content-fragile watermarks or for recognizing illegal content, the security of the hash value generation becomes an important issue. In this paper we discuss possible attacks on robust hash algorithms. As an example we describe a possible attack on the audio fingerprint of Haitsma et al., resulting in a different hash value while keeping the audio files perceptually similar.