New message difference for MD4

Abstract

This paper proposes several approaches to improve the collision attack on MD4 proposed by Wang et al. First, we propose a new local collision that is the best for the MD4 collision attack. Selection of a good message difference is the most important step in achieving effective collision attacks. This is the first paper to introduce an improvement to the message difference approach of Wang et al., where we propose a new local collision. Second, we propose a new algorithm for constructing differential paths. While similar algorithms have been proposed, they do not support the new local collision technique. Finally, we complete a collision attack, and show that the complexity is smaller than the previous best work. © International Association for Cryptologic Research 2007.