RISC-V Based Keccak Co-Processor for NIST Post-Quantum Cryptography Standards

This paper presents the design and implementation of a RISC-V-based Keccak co-processor optimized for Post-Quantum Cryptography (PQC) algorithms. Leveraging the Core-V eXtension InterFace (CV-X-IF), the co-processor extends the Instruction Set Architecture (ISA) with three custom instructions tailored for cryptographic operations. This allows seamless integration into various PQC schemes, tested across the multiple standards proposed by the National Institute of Standards and Technology (NIST), including CRYSTALS-Kyber, CRYSTALS-Dilithium, SPHINCS+, and FALCON, which are designed to withstand quantum attacks. By employing tightly coupled hardware acceleration, the Keccak co-processor dramatically reduces the computational overhead of hash-based operations central to these algorithms. The implementation is realized on a Xilinx Artix 7 FPGA, achieving a clock cycles’ improvement up to 75% and 19% resource overhead. The results presented herein demonstrate significant performance enhancement over the state of the art, underscoring its effectiveness for cryptographic applications.