International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 27 May 2013

Zheng Yuan, Xian Li, Haixia Liu
ePrint Report ePrint Report
CLEFIA is a 128-bit block cipher proposed by Sony Corporation in 2007. Our paper introduces a new chosen text attack, impossible differential-linear attack, on iterated cryptosystems. The attack is efficient for full-round CLEFIA without whitening keys. In the paper, we construct a 14-round impossible differential distinguisher. Based on the distinguisher, we present an effective attack on full-round CLEFIA-128 with data complexity of $2^{126.52}$, recovering 91-bit subkeys in total. Besides, the results of 15/16/17-round CLEFIA-128 are given in the Appendix B/C/D. Our attack can also applied to CLEFIA-192 and CLEFIA-256.

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