Near-Collisions on the Reduced-Round Compression Functions of Skein and BLAKE

Bozhan Su; Wenling Wu; Shuang Wu; Le Dong

Paper 2010/355

Near-Collisions on the Reduced-Round Compression Functions of Skein and BLAKE

Bozhan Su, Wenling Wu, Shuang Wu, and Le Dong

Abstract

The SHA-3 competition organized by NIST aims to find a new hash standard as a replacement of SHA-2. Till now, 14 submissions have been selected as the second round candidates, including Skein and BLAKE, both of which have components based on modular addition, rotation and bitwise XOR (ARX). In this paper, we propose improved near-collision attacks on the reduced-round compression functions of Skein and a variant of BLAKE. The attacks are based on linear differentials of the modular additions. The computational complexity of near-collision attacks on a 4-round compression function of BLAKE-32, 4-round and 5-round compression functions of BLAKE-64 are 2^{21}, 2^{16} and 2^{216} respectively, and the attacks on a 24-round compression functions of Skein-256, Skein-512 and Skein-1024 have a complexity of 2^{60}, 2^{230} and 2^{395} respectively.

Metadata

Available format(s): PDF
Publication info: Published elsewhere. Unknown where it was published
Keywords: Hash function Near-collision SHA-3 candidates Skein BLAKE
Contact author(s): subozhan @ is iscas ac cn
History: 2010-06-24: last of 2 revisions; 2010-06-18: received; See all versions
Short URL: https://ia.cr/2010/355
License: CC BY

BibTeX

@misc{cryptoeprint:2010/355,
      author = {Bozhan Su and Wenling Wu and Shuang Wu and Le Dong},
      title = {Near-Collisions on the Reduced-Round Compression Functions of Skein and {BLAKE}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2010/355},
      year = {2010},
      url = {https://eprint.iacr.org/2010/355}
}