SHARK
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For other uses, see SHARK (disambiguation).
Designer(s): | Vincent Rijmen, Joan Daemen, Bart Preneel, Antoon Bosselaers, Erik De Win |
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First published: | 1996 |
Successor(s): | KHAZAD, Rijndael |
Key size(s): | 128 bits |
Block size(s): | 64 bits |
Structure: | Substitution-permutation network |
Rounds: | 6 |
In cryptography, SHARK is a block cipher identified as one of the predecessors of Rijndael (the Advanced Encryption Standard).
SHARK has a 64-bit block size and a 128-bit key size. It is a six round SP-network which alternates a key mixing stage with linear and non-linear transformation layers. The linear transformation uses an MDS matrix representing a Reed-Solomon error correcting code in order to guarantee good diffusion. The nonlinear layer is composed of eight 8×8-bit S-boxes based on the function F(x) = x-1 over GF(28).
Five rounds of a modified version of SHARK can be broken using an interpolation attack (Jakobsen and Knudsen, 1997).
[edit] See also
[edit] References
- Vincent Rijmen, Joan Daemen, Bart Preneel, Anton Bosselaers, Erik De Win (1996-02). "The Cipher SHARK" (PDF/PostScript). 3rd International Workshop on Fast Software Encryption (FSE 1996): 99-111, Cambridge: Springer-Verlag. Retrieved on 2007-03-06.
- T. Jakobsen, L.R. Knudsen (1997-01). "The Interpolation Attack on Block Ciphers" (PDF/PostScript). 4th International Workshop on Fast Software Encryption (FSE '97): 28-40, Haifa: Springer-Verlag. Retrieved on 2007-01-23.
- Joan Daemen, Vincent Rijmen (2002). The Design of Rijndael: AES - The Advanced Encryption Standard. Springer-Verlag. ISBN 3-540-42580-2.