Efficient pipelining for modular multiplication architectures in prime fields

This paper presents a pipelined architecture of a modular Montgomery multiplier, which is suitable to be used in public key coprocessors. Starting from a baseline implementation of the Montgomery algorithm, a more compact pipelined version is derived. The design makes use of 16-bit integer multiplication blocks that are available on recently manufactured FPGAs. The critical path is optimized by omitting the exact computation of intermediate results in the Montgomery algorithm using a 6-2 carry-save notation. This results in a high-speed architecture,which outperforms previously designed Montgomery multipliers. Because a very popular application of Montgomery multiplication is public key cryptography, we compare our implementation to the state-of-the-art in Montgomery multipliers on the basis of performance results for 1024-bit RSA.