Comparing the cost of protecting selected lightweight block ciphers against differential power analysis in low-cost FPGAs

Abstract

Lightweight block ciphers are an important topic in the Internet of Things (IoT) since they provide moderate security while requiring fewer resources than the Advanced Encryption Standard (AES). Ongoing cryptographic contests and standardization efforts evaluate lightweight block ciphers on their resistance to power analysis side channel attack (SCA), and the ability to apply countermeasures. While some ciphers have been individually evaluated, a large-scale comparison of resistance to side channel attack and the formulation of absolute and relative costs of implementing countermeasures is difficult, since researchers typically use varied architectures, optimization strategies, technologies, and evaluation techniques. In this research, we leverage the Test Vector Leakage Assessment (TVLA) methodology and the FOBOS SCA framework to compare FPGA implementations of AES, SIMON, SPECK, PRESENT, LED, and TWINE, using a choice of architecture targeted to optimize throughput-to-area (TP/A) ratio and suitable for introducing countermeasures to Differential Power Analysis (DPA). We then apply an equivalent level of protection to the above ciphers using 3-share threshold implementations (TI) and verify the improved resistance to DPA. We find that SIMON has the highest absolute TP/A ratio of protected versions, as well as the lowest relative cost of protection in terms of TP/A ratio. Additionally, PRESENT uses the least energy per bit (E/bit) of all protected implementations, while AES has the lowest relative cost of protection in terms of increased E/bit.