Low-cost double-size modular exponentiation or how to stretch your cryptoprocessor

Abstract

Public-key implementers often face strong hardware-related constraints. In particular, modular operations required in most cryptosystems generally constitute a computational bottleneck in smart-card applications. This paper addresses the size limitation of arithmetic coprocessors and introduces new techniques that virtually increase their computational capacities. We suspect our algorithm to be nearly optimal and challenge the cryptographic community for better results.