Known-Key Attacks on Rijndael with Large Blocks and Strengthening ShiftRow Parameter


IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E95-A   No.1   pp.21-28
Publication Date: 2012/01/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E95.A.21
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Symmetric Cryptography
Rijndael,  known-key attack,  Super-Sbox analysis,  truncated differential path,  ShiftRow,  

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In this paper, we present known-key attacks on block cipher Rijndael for 192-bit block and 256-bit block. Our attacks work up to 8 rounds for 192-bit block and 9 rounds for 256-bit block, which are one round longer than the previous best known-key attacks. We then search for the parameters for the ShiftRow operation which is stronger against our attacks than the one in the Rijndael specification. Finally, we show a parameter for 192-bit block which forces attackers to activate more bytes to generate a truncated differential path, and thus enhances the security against our attacks.