Collisions for 70-Step SHA-1: On the Full Cost of Collision Search

The diversity of methods for fast collision search in SHA-1 and similar hash functions makes a comparison of them difficult. The literature is at times very vague on this issue, which makes comparison even harder. In situations where differences in estimates of attack complexity of a small factor might influence short-term recommendations of standardization bodies, uncertainties and ambiguities in the literature amounting to a similar order of magnitude are unhelpful. We survey different techniques and propose a simple but effective method to facilitate comparison. In a case study, we consider a newly developed attack on 70-step SHA-1, and give complexity estimates and performance measurements of this new and improved collision search method.

• Type: Conference
• Year: 2007
• Where: SACRYPT
• Authors: Christophe De Cannière, Florian Mendel, Christian Rechberger
• Keywords: Collision Search, Fast Collision Search, SACRYPT 2007, Similar Hash Functions