Anole: A Highly Efficient Dynamically Reconfigurable Crypto-Processor for Symmetric-Key Algorithms

Abstract

This paper presents a dynamically reconfigurable processing array named Anole for symmetric-key algorithms. Processing elements and the interconnections between them are designed to support various block and stream ciphers. Without affecting flexibility, three key techniques are presented to increase energy efficiency (throughput/power, the number of operations per unit energy consumption) and area efficiency (throughput/area). First, the distributed control network supports multithreading on reconfigurable fabrics at a low cost, thereby maximizing the utility of computing resources in the space domain. Second, the concurrent computation and reconfiguration scheme integrates configuration contexts with processing data to simultaneously execute in the data-path. The resulted immediate switching between different configurations increases the utilization rate of hardware resources in the temporal domain. Third, under configuration context compression and organization, the context memory size and configuration time are further minimized. Anole is implemented on a 7.75 mm2 silicon square with TSMC 65-nm technology at 400 MHz. Experiments show that Anole significantly outperforms field programmable gate array and general purpose processor by more than two orders of magnitude in energy and area efficiencies. Compared with state-of-the-art reconfigurable solutions, Anole achieves (average) $16.5\boldsymbol {\times }$ higher energy efficiency and $9.4\boldsymbol {\times }$ higher area efficiency.