Hardware Acceleration of the Tate Pairing in Characteristic Three

Although identity based cryptography offers many functional advantages over conventional public key alternatives, the computational costs are significantly greater. The core computational task is evaluation of a bilinear map, or pairing, over elliptic curves. In this paper we prototype and evaluate polynomial and normal basis field arithmetic on an FPGA device and use it to construct a hardware accelerator for pairings over fields of characteristic three. The performance of our prototype improves roughly ten-fold on previous known hardware implementations and orders of magnitude on the fastest known software implementation. As a result we reason that even on constrained devices one can usefully evaluate the pairing, a fact that gives credence to the idea that identity based cryptography is an ideal partner for identity aware smartcards.