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DesignersVincent Rijmen, Joan Daemen, Bart Preneel, Antoon Bosselaers, Erik De Win
First published1996
SuccessorsKHAZAD, Rijndael
Cipher detail
Key sizes128 bits
Block sizes64 bits
StructureSubstitution-permutation network

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).

See also


  • Vincent Rijmen, Joan Daemen, Bart Preneel, Anton Bosselaers, Erik De Win (February 1996). The Cipher SHARK (PDF/PostScript). 3rd International Workshop on Fast Software Encryption (FSE '96). Cambridge: Springer-Verlag. pp. 99–111. Retrieved 2007-03-06.
  • T. Jakobsen, L.R. Knudsen (January 1997). The Interpolation Attack on Block Ciphers (PDF/PostScript). 4th International Workshop on Fast Software Encryption (FSE '97). Haifa: Springer-Verlag. pp. 28–40. Retrieved 2007-01-23.
  • Joan Daemen; Vincent Rijmen (2002). The Design of Rijndael: AES—The Advanced Encryption Standard. Springer-Verlag. ISBN 3-540-42580-2.

External links