An Efficient Architecture of 1024-bits Cryptoprocessor for RSA Cryptosystem Based on Modified Montgomery's Algorithm

In this paper, a new architecture using only one carry save adder (CSA) was proposed to implement modular multiplication based on the modified Montgomery modular multiplication algorithm. It can improve the time efficiency of RSA cryptoprocessor and save about half of hardware resources for modular multiplication. With the increase of encryption data size n, the time of the encryption procedure is about n clock cycles which compared with the modular multiplication algorithm using two CSA.