Improved Differential Fault Attack on the Block Cipher SPECK

SPECK is a family of lightweight block ciphers published by the U.S. National Security Agency in 2013. The SPECK family consists of 10 versions, supporting a wide range of block and key sizes. Recently H. Tupsamudre et al. gave an approach to recovering the last round key of SPECK family with n/3 fault injections, where 2n is the block size. In this paper, we present two improved differential fault attacks on the SPECK family under different fault models. The first attack assumes a more practical random fault model and recovers the last round key with about 5 similar to 8 fault injections on all versions with different block sizes, which is far less than that of H. Tupsamudre et al.'s attack. The second attack only requires 4 specific faults to recover the last round key (except the most significant bit) over an arbitrary block size under a chosen-value fault model.