Table of contents

  • This session has been presented January 14, 2005.

Description

  • Speaker

    Antoine Joux - DGA/Université de Versailles

Dans cet exposé, nous examinerons quelques attaques récentes sur diverses fonctions de hachage itérées comme SHA-0 et MD5. Ces attaques basées sur la cryptanalyse différentielle ont permis la mise en évidence de collisions sur plusieurs de ces fonctions. Nous verrons comment, en détaillant le cas de SHA-0, et nous chercherons à identifier les conclusions à tirer suite à ces attaques. Nous verrons également que le principe même de fonctions de hachage itérées présente des particularités qui dans certains contextes peuvent conduire à des faiblesses par rapport à la modélisation théorique de la fonction de hachage par un oracle aléatoire.

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