International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Meltem Sönmez Turan

Publications

Year
Venue
Title
2015
EPRINT
2015
EPRINT
2015
EPRINT
2015
CHES
2015
FSE
2010
EPRINT
Message Recovery and Pseudo-Preimage Attacks on the Compression Function of Hamsi-256
Çagdas Çalik Meltem Sönmez Turan
Hamsi is one of the second round candidates of the SHA-3 competition. In this study, we present non-random differential properties for the compression function of the hash function Hamsi-256. Based on these properties, we first demonstrate a distinguishing attack that requires a few evaluations of the compression function and extend the distinguisher to 5 rounds with complexity $2^{83}$. Then, we present a message recovery attack with complexity of $2^{10.48}$ compression function evaluations. Also, we present a pseudo-preimage attack for the compression function with complexity $2^{254.25}$. The pseudo-preimage attack on the compression function is easily converted to a pseudo second preimage attack on Hamsi-256 hash function with the same complexity.

Program Committees

CHES 2016