Side Channel Attacks (SCA) have received a huge interest in the last 5 years. These new methods consider non-cryptographic sources of information (like timing or power consumption) in addition to traditional techniques. Consequently block ciphers must now resist a variety of SCAs, among which figures the class of “collision attacks”. This recent technique combines side channel information with tools originally developed for block cipher or hash function cryptanalysis, like differential cryptanalysis for instance.