Cryptology ePrint Archive: Report 2005/257

TMD-Tradeoff and State Entropy Loss Considerations of Streamcipher MICKEY

Jin Hong and Woo-Hwan Kim

Abstract: We give three weaknesses of a recently proposed streamcipher MICKEY. A small class of weak keys is found and we show time-memory-data tradeoff is applicable. We also show that the state update function reduces entropy of the internal state as it is iterated, resulting in keystreams that start out differently but become merged together towards the end.

Category / Keywords: secret-key cryptography / MICKEY, stream cipher, time memory data tradeoff, internal state entropy, weak key

Publication Info: Presented at Indocrypt 2005 (LNCS 3797, pp. 169-182)

Date: received 8 Aug 2005, last revised 6 Aug 2008

Contact author: whkim5 at ensec re kr

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Version: 20080806:235856 (All versions of this report)

Short URL: ia.cr/2005/257

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