Curved tags – a Low-Resource ECDSA implementation tailored for RFID

Abstract

In recent years, a lot of effort was made to deploy asymmetric cryptography based on ECC to affordable RFID tags. However, many proposed hardware designs suffer from long execution times and high resource requirements. In this paper, we address this issue by presenting a low-resource implementation of a 160-bit ECDSA signature generation algorithm. As a novelty, we make use of the new Keccak hashing algorithm. Moreover, we applied state of the art techniques such as co-Z ECC formulæ, a pipelined multiplication unit, RAM macros, and we evaluated fixed-base comb methods to improve the efficiency of ECDSA on passive tags. Furthermore, our design runs with constant runtime and provides basic resistance against common implementation attacks. It requires a total area of 12 448 GEs (including memory) and can generate a message digest within 140 kCycles, which is both smaller and considerably faster than comparable work. It has a power consumption of 42.7 μW at 1MHz on a low-leakage 130nm CMOS process technology. Our implementation can compete with binary-field based ECC solutions not only in terms of area and power but also in speed.