Chapter

Advances in Cryptology – ASIACRYPT 2011

Volume 7073 of the series Lecture Notes in Computer Science pp 252-269

Rebound Attack on JH42

  • María Naya-PlasenciaAffiliated withLancaster UniversityFHNW WindischUniversity of Versailles
  • , Deniz TozAffiliated withCarnegie Mellon UniversityESAT/COSIC and IBBT, Katholieke Universiteit Leuven
  • , Kerem VariciAffiliated withCarnegie Mellon UniversityESAT/COSIC and IBBT, Katholieke Universiteit Leuven

Abstract

The hash function JH [20] is one of the five finalists of the NIST SHA-3 hash competition. It has been recently tweaked for the final by increasing its number of rounds from 35.5 to 42. The previously best known results on JH were semi-free-start near-collisions up to 22 rounds using multi-inbound rebound attacks. In this paper we provide a new differential path on 32 rounds. Using this path, we are able to build various semi-free-start internal-state near-collisions and the maximum number of rounds that we achieved is up to 37 rounds on 986 bits. Moreover, we build distinguishers in the full 42-round internal permutation. These are, to our knowledge, the first results faster than generic attack on the full internal permutation of JH42, the finalist version. These distinguishers also apply to the compression function.

Keywords

hash function rebound attack JH cryptanalysis SHA-3