High-Performance FPGA Accelerator for SIKE

In this article, we provide improvements for the architecture of Supersingular Isogeny Key Encapsulation (SIKE), a post-quantum cryptography candidate. We develop a new highly optimized Montgomery multiplication algorithm and architecture for prime fields. The multiplier occupies less area and provide better timing results than the state-of-the-art. We also provide improvements to the scheduling of SIKE in our program ROM. We implement SIKE for all Round 3 NIST security levels (SIKEp434 for NIST security level 1, SIKEp503 for NIST security level 2, SIKEp610 for NIST security level 3, and SIKEp751 for NIST security level 5) on Xilinx Artix 7 and Xilinx Virtex 7 FPGAs. Our best implementation (NIST security level 1) runs 38 percent faster and occupies 30 percent less hardware resources in comparison to the leading counterpart available in the literature and implementations for other security levels achieved similar improvement.