Cryptanalysis of Dynamic SHA(2)
Cryptanalysis of Dynamic SHA(2)
In this paper, we analyze the hash functions Dynamic SHA and Dynamic SHA2, which have been selected as first round candidates in the NIST hash function competition. These hash functions rely heavily on data-dependent rotations, similar to certain block ciphers, e.g., RC5. Our analysis suggests that in the case of hash functions, where the attacker has more control over the rotations, this approach is less favorable than in block ciphers. We present practical, or close to practical, collision attacks on both Dynamic SHA and Dynamic SHA2. Moreover, we present a preimage attack on Dynamic SHA that is faster than exhaustive search.
- Katholieke Universiteit Leuven Belgium
- École Normale Supérieure France
- French National Centre for Scientific Research France
- KU Leuven Belgium
Technology, Science & Technology, PREIMAGES, cosic, SHA-3 candidate, Dynamic SHA2, MD5, Computer Science, Theory & Methods, HASH FUNCTIONS, Computer Science, hash function, collision attack, Dynamic SHA
Technology, Science & Technology, PREIMAGES, cosic, SHA-3 candidate, Dynamic SHA2, MD5, Computer Science, Theory & Methods, HASH FUNCTIONS, Computer Science, hash function, collision attack, Dynamic SHA
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