Automatic Security Evaluation for Bit-oriented Block Ciphers in Related-key Model: Application to PRESENT-80, LBlock and Others.
Siwei Sun, Lei Hu, Peng Wang · 2013
Abstract. Since AES and PRESENT are two international standard block ciphers representing the most elegant design strategies for byteoriented and bit-oriented designs respectively, we regard AES and PRES-ENT the two most significant candidates to scrutinize with respect to related-key differential attack. In EUROCRYPT 2010 and CRYPTO 2013, the security of AES with respect to related-key differential attack has been completely analyzed by Alex Biryukov et al and Pierre-Alain Fouque et al with automatic related-key differential characteristic searching tools. In this paper, we propose two methods to describe the differential behaviour of an S-box with linear inequalities based on logical condition modelling and computational geometry. In one method, inequalities are generated according to some conditional differential properties of the S-box; in the other method, inequalities are extracted from the H-representation of the convex hull of all possible differential patterns of the S-box. For the second method, we develop a greedy algorithm