High-throughput block cipher implementations with SIMD

Abstract

The development of new technologies has put forward higher requirements for the performance and security of block ciphers. To meet the needs of these situations, Bitslicing is one of the block cipher implementation techniques which can provide high efficiency and resistance to cache-timing attacks. The S-box is usually the most time-consuming component for Bitsliced implementations. In this paper, we present techniques to optimize the S-box implementation and derive the most compact representations available for Bitslicing. Then we show that the efficiency of linear layers can be further improved by introducing a state-of-the-art technique. As a result, our implementations have significant advantages over previous implementations. The throughputs of our AES and SM4 implementations achieve 27068Mbps and 30026Mbps on i5-11335G7, both exceeding the throughput of AES-NI on the same platform.