Collisions for the LPS Expander Graph Hash Function

  • Jean-Pierre Tillich
  • Gilles Zémor
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4965)

Abstract

We analyse the hash function family based on walks in LPS Ramanujan graphs recently introduced by Charles et al. We present an algorithm for finding collisions that runs in quasi-linear time in the length of the hashed value. A concrete instance of the hash function is considered, based on a 100-digit prime. A short collision is given, together with implementation details.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Jean-Pierre Tillich
    • 1
  • Gilles Zémor
    • 2
  1. 1.INRIA, Équipe SECRET, Rocquencourt, 78153 Le ChesnayFrance
  2. 2.Institut de Mathématiques de BordeauxUniversité Bordeaux 1TalenceFrance

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