## Cryptology ePrint Archive: Report 2015/964

Improved Linear (hull) Cryptanalysis of Round-reduced Versions of KATAN

Danping Shi and Lei Hu and Siwei Sun and Ling Song

Abstract: KATAN is a family of block ciphers published at CHES 2009. Based on the Mixed-integer linear programming (MILP) technique, we propose the first third-party linear cryptanalysis on KATAN. Furthermore, we evaluate the security of KATAN against the linear attack without ignoring the dependence of the input bits of the $2\times 1$ S-box(the AND operation). Note that in previous analysis, the dependence is not considered, and therefore the previous results are not accurate. Furthermore, the mounted 131/120-round attack on KATAN32/48 respectively by our 84/90-round linear hull is the best single-key known-plaintext attack. In addition, a best 94-round linear hull attack is mounted on KATAN64 by our 76-round linear hull.

Category / Keywords: KATAN, Mixed-integer linear programming, linear hull, dependence

Date: received 6 Oct 2015, last revised 20 Nov 2015

Contact author: shidanping at iie ac cn

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2015/964

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