Linearization Attacks Against Syndrome Based Hashes

Markku-Juhani O.  Saarinen

Paper 2007/295

Linearization Attacks Against Syndrome Based Hashes

Markku-Juhani O. Saarinen

Abstract

In MyCrypt 2005, Augot, Finiasz, and Sendrier proposed FSB, a family of cryptographic hash functions. The security claim of the FSB hashes is based on a coding theory problem with hard average-case complexity. In the ECRYPT 2007 Hash Function Workshop, new versions with essentially the same compression function but radically different security parameters and an additional final transformation were presented. We show that hardness of average-case complexity of the underlying problem is irrelevant in collision search by presenting a linearization method that can be used to produce collisions in a matter of seconds on a desktop PC for the variant of FSB with claimed $2^128$ security.

Note: Sample code for matrix arithmetic and pre-image search can be downloaded from: http://www.m-js.com/misc/fsb_test.tar.gz

Metadata

Available format(s): PDF PS
Category: Secret-key cryptography
Publication info: Published elsewhere. INDOCRYPT 2007
Keywords: hash function cryptanalysis provable security linearization attack FSB
Contact author(s): m saarinen @ rhul ac uk
History: 2007-09-25: last of 6 revisions; 2007-08-07: received; See all versions
Short URL: https://ia.cr/2007/295
License: CC BY

BibTeX

@misc{cryptoeprint:2007/295,
      author = {Markku-Juhani O.  Saarinen},
      title = {Linearization Attacks Against Syndrome Based Hashes},
      howpublished = {Cryptology ePrint Archive, Paper 2007/295},
      year = {2007},
      note = {\url{https://eprint.iacr.org/2007/295}},
      url = {https://eprint.iacr.org/2007/295}
}