New local collisions for the SHA-2 hash family
ICISC'07 Proceedings of the 10th international conference on Information security and cryptology
Analysis of step-reduced SHA-256
FSE'06 Proceedings of the 13th international conference on Fast Software Encryption
Finding collisions in the full SHA-1
CRYPTO'05 Proceedings of the 25th annual international conference on Advances in Cryptology
How to break MD5 and other hash functions
EUROCRYPT'05 Proceedings of the 24th annual international conference on Theory and Applications of Cryptographic Techniques
Non-linear Reduced Round Attacks against SHA-2 Hash Family
ACISP '08 Proceedings of the 13th Australasian conference on Information Security and Privacy
Deterministic Constructions of 21-Step Collisions for the SHA-2 Hash Family
ISC '08 Proceedings of the 11th international conference on Information Security
New Collision Attacks against Up to 24-Step SHA-2
INDOCRYPT '08 Proceedings of the 9th International Conference on Cryptology in India: Progress in Cryptology
Distinguishing Attack on the Secret-Prefix MAC Based on the 39-Step SHA-256
ACISP '09 Proceedings of the 14th Australasian Conference on Information Security and Privacy
Second-Order differential collisions for reduced SHA-256
ASIACRYPT'11 Proceedings of the 17th international conference on The Theory and Application of Cryptology and Information Security
Finding SHA-2 characteristics: searching through a minefield of contradictions
ASIACRYPT'11 Proceedings of the 17th international conference on The Theory and Application of Cryptology and Information Security
Converting meet-in-the-middle preimage attack into pseudo collision attack: application to SHA-2
FSE'12 Proceedings of the 19th international conference on Fast Software Encryption
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In this article we find collisions for step-reduced SHA-256. We develop a differential that holds with high probability if the message satisfies certain conditions. We solve the equations that arise from the conditions. Due to the carefully chosen differential and word differences, the message expansion of SHA-256 has little effect on spreading the differences in the words. This helps us to find full collision for 21-step reduced SHA-256, semi-free start collision, i.e. collision for a different initial value, for 23-step reduced SHA-256, and semi-free start near collision (with only 15 bit difference out of 256 bits) for 25-step reduced SHA-256.