CRYPTONITE: Scalable Accelerator Design for Cryptographic Primitives and Algorithms

Abstract: Cryptographic primitives, consisting of repetitive operations with different inputs, are typically implemented using straight-line C code due to traditional execution on CPUs. Computing these primitives is necessary for secure communication; thus, dedicated hardware accelerators are required in resource and latency-constrained environments. High-Level Synthesis (HLS) generates hardware from high-level implementations in languages like C, enabling the rapid prototyping and evaluation of designs, leading to its prominent use in developing dedicated hardware accelerators. However, directly synthesizing the straight-line C implementations of cryptographic primitives can lead to large hardware designs with excessive resource usage or suboptimal performance. We introduce Cryptonite, a tool that automatically generates efficient, synthesizable, and correct-by-design hardware accelerators for cryptographic primitives directly from straight-line C code. Cryptonite first identifies high-level hardware constructs through verified rewriting, emphasizing resource reuse. The second stage automatically explores latency-oriented implementations of the compact design. This enables the flexible scaling of a particular accelerator to meet the hardware requirements. We demonstrate Cryptonite's effectiveness using implementations from the Fiat Cryptography project, a library of verified and auto-generated cryptographic primitives for elliptic-curve cryptography. Our results show that Cryptonite achieves scalable designs with up to 88.88\% reduced resource usage and a 54.31\% improvement in latency compared to naively synthesized designs.