Unifier register to protect an efficient modular exponentiation algorithm

Simple power analysis (SPA) attacks are widely used against several cryptosystems, principally against those based on modular exponentiation. Many types of SPA have been reported in the literature in the recent years. There is a real necessity to eliminate the vulnerabilities of cryptosystems, such as CRT-RSA or the Elliptic Curve Cryptosystem, that make them susceptible to these attacks. There are many modular exponentiation algorithms that try to reinforce the security of these systems, of which one was proposed by Da-Zhi et al. Da-zhi’s algorithm was presented as a secure and efficient countermeasure against side channel attacks; however, recently it was shown that its security can be defeated. In this paper, a means of protecting the algorithm is presented. The proposed technique can be applied in any algorithm that computes dummy operations through its execution.