A Flexible and Energy-Efficient BLAKE-256/2s Co-Processor for Blockchain-based IoT Applications

Developing flexible and energy-efficient BLAKE-256/2s hardware has recently become necessary since BLAKE-256 and BLAKE2s are important cryptographic hash functions in reliability and security enhancement for blockchain-based IoT applications. However, previous BLAKE-256/2s architectures are challenging in achieving high flexibility and energy efficiency. Therefore, this paper proposes the BLAKE-256/2s co-processor to achieve high flexibility and energy efficiency for blockchain-based IoT applications. The proposed BLAKE-256/2s accelerator has three novel optimization techniques to achieve those goals. First, a configurable hashing core is proposed to enhance flexibility. Second, a pipelined permutation and compression architecture are developed to improve the throughput and hardware efficiency. Third, a mining transmission mechanism is introduced to optimize the performance of our co-processor at the system-on-chip level. The proposed co-processor is implemented and verified on a Xilinx Zynq $\mathbf{UltraScale}+$ MPSoC ZCU102 FPGA. Accordingly, the power and energy efficiency of the co-processor on the ZCU102 FPGA is significantly better than the Intel i9 10940X CPU and the RTX 3090 GPU. Moreover, experimental results on several FPGAs prove that the proposed co-processor is considerably higher throughput, area efficiency, and flexibility than FPGA-based related works.