Skip to main content
Article thumbnail
Location of Repository

A new baby-step giant-step algorithm and some applications to cryptanalysis

By Jean Sébastien Coron, David Lefranc and Guillaume Poupard


Abstract. We describe a new variant of the well known Baby-Step Giant-Step algorithm in the case of some discrete logarithms with a special structure. More precisely, we focus on discrete logarithms equal to products in groups of unknown order. As an example of application, we show that this new algorithm enables to cryptanalyse a variant of the GPS scheme proposed by Girault and Lefranc at CHES 2004 conference in which the private key is equal to the product of two sub-private keys of low Hamming weight. We also describe a second attack based on a known variant of the Baby-Step Giant-Step algorithm using the low Hamming weight of the sub-private keys. Key words: Baby-Step Giant-Step algorithm, discrete logarithm, GPS scheme, binary trees, low Hamming weight.

Publisher: Springer
Year: 2005
OAI identifier: oai:CiteSeerX.psu:
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.