International Workshop on Fast Software Encryption

FSE 2010: Fast Software Encryption pp 318-332

Differential and Invertibility Properties of BLAKE

  • Jean-Philippe Aumasson
  • Jian Guo
  • Simon Knellwolf
  • Krystian Matusiewicz
  • Willi Meier
Conference paper

DOI: 10.1007/978-3-642-13858-4_18

Volume 6147 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Aumasson JP., Guo J., Knellwolf S., Matusiewicz K., Meier W. (2010) Differential and Invertibility Properties of BLAKE. In: Hong S., Iwata T. (eds) Fast Software Encryption. FSE 2010. Lecture Notes in Computer Science, vol 6147. Springer, Berlin, Heidelberg

Abstract

BLAKE is a hash function selected by NIST as one of the 14 second round candidates for the SHA-3 Competition. In this paper, we follow a bottom-up approach to exhibit properties of BLAKE and of its building blocks: based on differential properties of the internal function G, we show that a round of BLAKE is a permutation on the message space, and present an efficient inversion algorithm. For 1.5 rounds we present an algorithm that finds preimages faster than in previous attacks. Discovered properties lead us to describe large classes of impossible differentials for two rounds of BLAKE’s internal permutation, and particular impossible differentials for five and six rounds, respectively for BLAKE-32 and BLAKE-64. Then, using a linear and rotation-free model, we describe near-collisions for four rounds of the compression function.

Keywords

cryptanalysishash functionsSHA-3
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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Jean-Philippe Aumasson
    • 1
  • Jian Guo
    • 2
  • Simon Knellwolf
    • 3
  • Krystian Matusiewicz
    • 4
  • Willi Meier
    • 3
  1. 1.Nagravision SACheseauxSwitzerland
  2. 2.Nanyang Technological UniversitySingapore
  3. 3.FHNW, WindischSwitzerland
  4. 4.Technical University of DenmarkDenmark