Elliptic-curve crypto processor for RFID applications

This work presents an Elliptic-curve Point Multiplication (ECP) architecture with a focus on low latency and low area for radio-frequency-identification (RFID) applications over GF(2¹⁶³). To achieve low latency, we have reduced the clock cycles by using: (i) three-shift buffers in the datapath to load Elliptic-curve parameters as well as an initial point, (ii) the identical size of input/output interfaces in all building blocks of the architecture. The low area is preserved by using the same hardware resources of squaring and multiplication for inversion computation. Finally, an efficient controller is used to control the inferred logic. The proposed ECP architecture is modeled in Verilog and the synthesis results are given on three different 7-series FPGA (Field Programmable Gate Array) devices, i.e., Kintex-7, Artix-7, and Virtex-7. The performance of the architecture is provided with the integration of a schoolbook multiplier (implemented with two different logic styles, i.e., combinational and sequential). On Kintex-7, the combinational implementation style of a schoolbook multiplier results in power-optimized, i.e., 161 µW, values with an expense of (i) hardware resources, i.e., 3561 look-up-tables and 1527 flip-flops, (ii) clock frequency, i.e., 227 MHz, and (iii) latency, i.e., 11.57 µs. On the same Kintex-7 device, the sequential implementation style of a schoolbook multiplier provides, (i) 2.88 µs latency, (ii) 1786 look-up-tables and 1855 flip-flops, (iii) 647 µW power, and (iv) 909 MHz clock frequency. Therefore, the reported area, latency and power results make the proposed ECP architecture well-suited for RFID applications.