Second-Order Differential Collisions for Reduced SHA-256
| Autor: | Alex Biryukov, Mario Lamberger, Ivica Nikoli, Florian Mendel |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Computer science [C05] [Engineering
computing & technology] non-randomness higher-order differentials Hash function Hash functions 020206 networking & telecommunications 02 engineering and technology Function (mathematics) Sciences informatiques [C05] [Ingénierie informatique & technologie] Collision SHA-256 Margin (machine learning) Search algorithm 0202 electrical engineering electronic engineering information engineering Cryptographic hash function 020201 artificial intelligence & image processing Rectangle SHACAL-2 Algorithm Mathematics Block cipher |
| Zdroj: | Lecture Notes in Computer Science ISBN: 9783642253843 ASIACRYPT 17th International Conference on the Theory and Application of Cryptology and Information Security (pp. 270-287). Springer (2011). |
| DOI: | 10.1007/978-3-642-25385-0_15 |
| Popis: | In this work, we introduce a new non-random property for hash/compression functions using the theory of higher order differentials. Based on this, we show a second-order differential collision for the compression function of SHA-256 reduced to 47 out of 64 steps with practical complexity. We have implemented the attack and provide an example. Our results suggest that the security margin of SHA-256 is much lower than the security margin of most of the SHA-3 finalists in this setting. The techniques employed in this attack are based on a rectangle/boomerang approach and cover advanced search algorithms for good characteristics and message modification techniques. Our analysis also exposes flaws in all of the previously published related-key rectangle attacks on the SHACAL-2 block cipher, which is based on SHA-256. We provide valid rectangles for 48 steps of SHACAL-2. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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