A Key Size Configurable High Speed RSA Coprocessor

The RSA algorithm is the most used public key cipher algorithm. Since it was presented in 1977, designers have proposed several architectures and implementations to improve its performance using different techniques and devices. In all cases, Montgomery´s modular multiplication algorithm is the best option when trying to design an efficient RSA. In this paper, we present a high-radix Montgomery´s algorithm implementation. The main advantages of this approach are the scalability and modularity, which allow finding the best tradeoff between area and performance depending on the application. The system is able to process different RSA key lengths without needing to reconfigure it.