Design trade-offs in SHA-3 multi-message hashing on FPGAs

Hash functions are widely used to check whether the data are correctly transferred. Keccak is an important hash function that was selected as SHA-3 in 2012. In this paper, we propose and evaluate the optimized FPGA implementations of Keccak for multi-message hashing. Our optimizations include a variety of pipeline organizations, retiming of a part of the calculation, and the use of DSP units. According to the evaluation results, our implementation exhibited 52% higher throughput/area than the previous one on a Xilinx Virtex-5 FPGA. Although the above design adopted advanced DSP units that support bitwise XOR, 20% improvement was achieved even on a Spartan-6 with simpler multiply-adders.