International Association
for Cryptologic Research

The hash function FORK-256 was published at the ¯rst NIST hash workshop and FSE 2006. It consists of simple operations so that its performance is better than that of SHA-256. However, recent papers show some weaknesses of FORK-256. In this paper, we propose newly modi¯ed FORK-256 which has no microcoliisions and so is resistant against existing attacks. Furthermore, it is faster than the old one.