CryptRISC: A Secure RISC-V Processor for High-Performance Cryptography with Power Side-Channel Protection

Abstract: Cryptographic computations are fundamental to modern computing, ensuring data confidentiality and integrity. However, these operations are highly vulnerable to power side-channel attacks that exploit variations in power consumption to leak sensitive information. Masking is a widely used countermeasure, yet software-based techniques often introduce significant performance overhead and implementation complexity, while fixed-function hardware masking lacks flexibility across diverse cryptographic algorithms. In this paper, we present CryptRISC, the first RISC-V-based processor that combines cryptographic acceleration with hardware-level power side-channel resistance through an ISA-driven operand masking framework. Our design extends the CVA6 core with 64-bit RISC-V Scalar Cryptography Extensions and introduces two microarchitectural components: a Field Detection Layer, which identifies the dominant algebraic field of each cryptographic instruction, and a Masking Control Unit, which applies field-aware operand randomization at runtime. This enables dynamic selection of Boolean, affine, or arithmetic masking schemes based on instruction semantics, providing optimized protection across algorithms including AES, SHA-256, SHA-512, SM3, and SM4. Unlike prior approaches relying on static masking logic or software instrumentation, our method performs operand masking transparently within the execution pipeline without modifying instruction encoding. Experimental results show speedups up to 6.80$\times$ over baseline software implementations, with only a 1.86% hardware overhead relative to the baseline CVA6 core, confirming the efficiency and practicality of CryptRISC.