Abstract. Since Crypto 2004, hash functions have been the target of many attacks which showed that several well-known functions such as SHA-0 or MD5 can no longer be considered secure collision free hash functions. These attacks use classical cryptographic techniques from block cipher analysis such as differential cryptanalysis together with some specific methods. Among those, we can cite the neutral bits of Biham and Chen or the message modification techniques of Wang et al. In this paper, we show that another tool of block cipher analysis, the boomerang attack, can also be used in this context. In particular, we show that using this boomerang attack as a neutral bits tool, it becomes possible to lower the complexity of the attacks on SHA-1.
A previous application of the boomerang attack to hash functions is due to Joux and Peyrin REF , who used the boomerang attack as a neutral bits tool to speed-up existing collision attacks.
Hash functions and the (amplified) boomerang attack
CRYPTO
Computer Science