Designing efficient elliptic Curve Diffie-Hellman accelerators for embedded systems

In this paper, a methodology towards a hardware/software implementation of an Elliptic Curve Diffie Hellman (ECDH) scheme is proposed in an effort to overcome the design problems of Elliptic Curve Cryptography (ECC) systems stemming from the highly constrained embedded system hardware and software environment (restricted RAM, storage and processing power). To achieve that, instead of the excessively slow software ECDH implementations or monolithic, not flexible hardware implementations, we propose the use of a flexible, scalar multiplication (SM) accelerator connected to the main embedded system processor in order to speed up ECDH functionality without downgrading the overall main processor performance. The proposed solution can be used for a wide variety of GF(2^k) based Elliptic Curves (EC) and is capable of shifting from one EC to another EC at runtime (flexibility). The proposed architecture was implemented and tested in Xilinx Virtex 5 technology by realizing the proposed SM accelerator unit interconnected with a Xilinx microblaze softcore processor.