Notes on the Wang et al. 2 63 SHA-1 Differential Path.
Martin Cochran · 2007
Although advances in SHA-1 cryptanalysis have been made since the 2005 announcement of a2 63 attack by Wang et al., the details of the attack have not yet been vetted; this note does just that. Working from Adi Shamir’s 2005 CRYPTO rump session presentation of Wang et al.’s work, this note corroborates and presents the differential path and associated conditions for the two-block attack. Although the error analysis for the advanced condition correction technique is not verified, a method is given which yields a two-block collision attack on SHA-1 requiring an estimated 2 62 SHA-1 computations if the original error analysis by Wang et al. is correct.