Differential Cryptanalysis of Round-Reduced LEA

In this paper, we focus on the differential cryptanalysis dedicated to a particular class of cryptographic algorithms, namely ARX ciphers. We propose a new algorithm inspired by the Nested Monte-Carlo Search algorithm to find a differential path in ARX ciphers. We apply our algorithm to a round reduced variant of the block cipher LEA. For small blocks of ARX ciphers, our algorithm works perfectly and in an extremely concise time. Taking into...