Efficient one-pass entity authentication based on ECC for constrained devices

In this contribution, we present a highly efficient single-message protocol for repeated entity authentication based on Elliptic Curve Cryptography (ECC). Repeated unilateral authentication is used in scenarios where a prover repeatedly authenticates himself to the same verifier. Our protocol requires the transfer of only one single message for this purpose and reduces the required computations on the prover´s side to a minimum which supports efficient implementations. In order to support this, a three pass setup protocol has to performed once. We have proven the efficiency of our approach through a prototype implementation of a remote keyless entry system including a microcontroller and an FPGA-based, GF(2¹⁶³) Elliptic Curve (EC) co-processor which features state-of-the-art measures against simple and differential power analysis and fault attacks. General modular arithmetic is performed on the microcontroller and the EC scalar point multiplication is executed in 93.5k clock cycles on the FPGA based EC co-processor which has a hardware complexity of 12.7k gate equivalents. Our implementation results confirm the efficiency of our protocol for application scenarios where repeated authentication is performed through low-energy, uni-directional devices like in remote access control.