TMD-Tradeoff and State Entropy Loss Considerations of Streamcipher MICKEY

Jin Hong; Woo-Hwan Kim

Paper 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.

Metadata

Available format(s): PDF PS
Category: Secret-key cryptography
Publication info: Published elsewhere. Presented at Indocrypt 2005 (LNCS 3797, pp. 169-182)
Keywords: MICKEY stream cipher time memory data tradeoff internal state entropy weak key
Contact author(s): whkim5 @ ensec re kr
History: 2008-08-06: revised; 2005-08-11: received; See all versions
Short URL: https://ia.cr/2005/257
License: CC BY

BibTeX

@misc{cryptoeprint:2005/257,
      author = {Jin Hong and Woo-Hwan Kim},
      title = {{TMD}-Tradeoff and State Entropy Loss Considerations of Streamcipher {MICKEY}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2005/257},
      year = {2005},
      url = {https://eprint.iacr.org/2005/257}
}