A 3-Stage Pipelined Large Integer Modular Arithmetic Unit for ECC

Large integer modular multiplication and modular addition/subtraction are basic operations in elliptic curve cryptography (ECC). Traditionally, systolic array was used to implement modular multiplication. It is not efficient because of data dependency between neighbor processing elements (PEs). In this paper, we propose a compact modular multiplication and addition unit (MMAU) specific for ECC by dividing an improved Montgomery modular multiplication (MMM) algorithm into three parts, mapping them correspondingly to a 3-stage pipelined circuit and adding a small amount of hardware to the third stage of the pipeline for implementing modular addition/subtraction without affecting the performance of MMM. The MMAU computes one modular multiplication and one modular addition/subtraction in every 3(n+7) clock cycles for n-bit operands. When the pipeline is fully utilized, the MMAU can generate a result at every n+7 cycles. The experimental results show that our scheme achieves a higher throughput with less resource compared with existed ones.