Attacks on Fast Double Block Length Hash Functions

Abstract

The security of hash functions based on a block cipher with a block length of m bits and a key length of k bits, where k < m, is considered. New attacks are presented on a large class of iterated hash functions with a 2m-bit hash result which processes in each iteration two message blocks using two encryptions. In particular, the attacks break three proposed schemes: Parallel-DM, the PBGV hash function, and the LOKI DBH mode. © 1998 International Association (or Cryptologio Research.