Collision Attack on 4-Branch, Type-2 GFN Based Hash Functions Using Sliced Biclique Cryptanalysis Technique

TLDR: In this article, the sliced biclique cryptanalysis technique was applied to show 8-round collision attack on a hash function, which is based on 4-branch, Type-2 Generalized Feistel Network (Type-2 GFN).

Abstract: In this work, we apply the sliced biclique cryptanalysis technique to show 8-round collision attack on a hash function \(H\) based on 4-branch, Type-2 Generalized Feistel Network (Type-2 GFN) This attack is generic and works on 4-branch, Type-2 GFN with any parameters including the block size, type of round function, the number of S-boxes in each round and the number of SP layers inside the round function We first construct a 8-round distinguisher on 4-branch, Type-2 GFN and then use this distinguisher to launch 8-round collision attack on compression functions based on Matyas-Meyer-Oseas (MMO) and Miyaguchi-Preneel (MP) modes The complexity of the attack on 128-bit compression function is \(2^{56}\) The attack can be directly translated to collision attack on MP and MMO based hash functions and pseudo-collision attack on Davies-Meyer (DM) based hash functions When the round function \(F\) is instantiated with double SP layer, we show the first 8 round collision attack on 4-branch, Type-2 GFN with double SP layer based compression function The previous best attack on this structure was a 6-round near collision attack shown by Sasaki at Indocrypt’12 His attack cannot be used to generate full collisions on 6-rounds and hence our result can be regarded the best so far in literature on this structure