Paper 2009/038

On Algebraic Relations of Serpent S-Boxes

Bhupendra Singh, Lexy Alexander, and Sanjay Burman


Serpent is a 128-bit block cipher designed by Ross Anderson, Eli Biham and Lars Knudsen as a candidate for the Advanced Encryption Standard (AES). It was a finalist in the AES competition. The winner, Rijndael, got 86 votes at the last AES conference while Serpent got 59 votes [1]. The designers of Serpent claim that Serpent is more secure than Rijndael.In this paper we have observed that the nonlinear order of all output bits of serpent S-boxes are not 3 as it is claimed by the designers.

Note: We find that there is some discrepancy between the properties of the actual S-boxes of Serpent and the claims of the designers. It is surprising that this has not been pointed out by any body so long. This leads the revisiting the Security of the serpent.

Available format(s)
Secret-key cryptography
Publication info
Published elsewhere. Not published elsewhere
Contact author(s)
scientistbsingh @ gmail com
2009-01-25: received
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Creative Commons Attribution


      author = {Bhupendra Singh and Lexy Alexander and Sanjay Burman},
      title = {On Algebraic Relations of Serpent S-Boxes},
      howpublished = {Cryptology ePrint Archive, Paper 2009/038},
      year = {2009},
      note = {\url{}},
      url = {}
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