Energy-Efficient Unified Multi-Hash Coprocessor for Securing IoT Systems Integrating Blockchain

SHA-256, BLAKE-256, and BLAKE2s are cryptographic hash functions widely used in data security for Blockchain-enabled IoT systems to ensure the integrity of data and transactions. However, previous works have focused solely on implementing individual hash functions from these three cryptographic hash functions. Therefore, we propose a unified hardware solution named a B2$HA coprocessor that integrates all three hash functions and offers high speed, low power consumption, and high flexibility. Our proposed approach involves three novel optimizations: a multi-level pipeline architecture, a reused-register technique, and an adder-sharing method. The theoretical evaluation demonstrates that B2$HA coprocessor shares 76.5% of 32-bit registers (104 out of 136) and 84.6% of 32-bit adders (44 out of 52) for SHA-256, BLAKE-256, and BLAKE2s computations. Additionally, the implementation results on the 45 nm CMOS ASIC show that the unified efficiency of B2$HA is approximately 82%. The B2$HA coprocessor is implemented and verified at the system-on-chip level on the Xilinx Zynq UltraScale+ MPSoC ZCU102 FPGA. Our experimental results on multiple FPGAs show that the B2$HA coprocessor exhibits superior flexibility and outperforms stand-alone hashing architectures in terms of throughput and area efficiency by 1.938.4 times and 1.4-4.5 times, respectively.