## Cryptology ePrint Archive: Report 2014/986

Related-Key Differential Attack on Round Reduced RECTANGLE-80

Jinyong Shan and Lei Hu and Ling Song and Siwei Sun and Xiaoshuang Ma

Abstract: RECTANGLE is a newly proposed lightweight block cipher which allows fast implementations for multiple platforms by using bit-slice techniques. It is an iterative 25-round SPN block cipher with a 64-bit block size and a 80-bit or 128-bit key size. Until now, the results on analyzing the cipher are not too much, which includes an attack on the 18-round reduced version proposed by the designers themselves. In this paper, we find all 15-round differential characteristics with 26--30 active S-boxes for given input, output and round subkey differences, which have a total probability $2^{-60.5}$. Based on these differential characteristics, we extend the corresponding distinguisher to 2 rounds backward and forward respectively, and propose an attack on the 19-round reduced RECTANGLE-80 with data complexity of $2^{62}$ plaintexts, time complexity of about $2^{67.42}$ encryptions and memory complexity of $2^{72}$. TThese data and time complexities are much lower than that of the designers for the 18-round reduced RECTANGLE-80.

Category / Keywords: secret-key cryptography / RECTANGLE block cipher, Mixed-integer linear programming, Related-key differential attack

Date: received 9 Dec 2014, last revised 10 Dec 2014

Contact author: jyshan12 at is ac cn

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2014/986

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