Higher-Order Differential Properties of Keccak and Luffa

  • Christina Boura
  • Anne Canteaut
  • Christophe De Cannière
Conference paper

DOI: 10.1007/978-3-642-21702-9_15

Part of the Lecture Notes in Computer Science book series (LNCS, volume 6733)
Cite this paper as:
Boura C., Canteaut A., De Cannière C. (2011) Higher-Order Differential Properties of Keccak and Luffa. In: Joux A. (eds) Fast Software Encryption. FSE 2011. Lecture Notes in Computer Science, vol 6733. Springer, Berlin, Heidelberg

Abstract

In this paper, we identify higher-order differential and zero-sum properties in the full Keccak-f permutation, in the Luffa v1 hash function and in components of the Luffa v2 algorithm. These structural properties rely on a new bound on the degree of iterated permutations with a nonlinear layer composed of parallel applications of a number of balanced Sboxes. These techniques yield zero-sum partitions of size 21575 for the full Keccak-f permutation and several observations on the Luffa hash family. We first show that Luffa v1 applied to one-block messages is a function of 255 variables with degree at most 251. This observation leads to the construction of a higher-order differential distinguisher for the full Luffa v1 hash function, similar to the one presented by Watanabe et al. on a reduced version. We show that similar techniques can be used to find all-zero higher-order differentials in the Luffa v2 compression function, but the additional blank round destroys this property in the hash function.

Keywords

Hash functions degree higher-order differentials zero-sums SHA-3 
Download to read the full conference paper text

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Christina Boura
    • 1
    • 2
  • Anne Canteaut
    • 1
  • Christophe De Cannière
    • 3
  1. 1.SECRET Project-Team - INRIA Paris-RocquencourtLe Chesnay CedexFrance
  2. 2.GemaltoMeudon sur SeineFrance
  3. 3.Department of Electrical Engineering ESAT/SCD-COSICKatholieke Universiteit LeuvenHeverleeBelgium

Personalised recommendations