Improved low-entropy masking scheme for LED with mitigation against correlation-enhanced collision attacks

Recent lightweight cryptographic algorithms are vulnerable to side channel attacks (SCA), requiring a careful design of implementations. In this paper, we carefully investigate the “Low-Entropy Masking Scheme” (LEMS) on the block cipher LED in the context of resource-constrained environments. We propose an improved LEMS called “iM-LED”, so as to satisfy two different yet unified design goals: to maintain the entropy of the masking at one bit, meanwhile, to enhance first-order SCA-resistance against advanced SCAs such as correlation-enhanced collision attack (CCA). The security of the implementation has been evaluated based on the SASEBO-W board, which proves that iM-LED has boosted its mitigation against SCA with limited overheads.