Improved Integral Attacks on Reduced-Round CLEFIA Block Cipher

摘要

In this paper a new 9-round integral distinguisher of CLE FIA is proposed based on byte-pattern, which is proved in detail. Then by using the partial sum technique we improve the previous result on 11-round CLEFIA and proposed integral attack on 12-, 13- and 14- round CLEFIA with the whitening keys. The 12-round CLEFIA-128/192/256 is attacked with data complexity 2~(113) and time complexity 2~(116.7), 13-round CLEFIA-192/256 is attacked with data complexity 2~(113) and time complexity 2~(180.5), and 14-round CLEFIA-256 is breakable with data com plexity 2~(113) and time complexity 2~(244.5). These results demonstrate that based on the byte-pattern we can improve the integral attacks on CLE FIA two more rounds than those given by the designers.