How to Avoid the N-1 Attack Without Costly Implementations
Simple Power Analysis (SPA) attacks are widely used against several cryptosystems, principally against cryptosystems based on modular exponentiation. Many types of SPA have been reported in the literature, Yen et al. introduced the N-1 attack, which uses chosen input messages to obtain relevant information from the attacked cryptosystem. Their attack was implemented on the square-and-multiply always and on the BRIP algorithm, both algorithms in left-to-right form. There are possible countermeasures against this attack, but all of them are costly and time consuming. In this paper, a computationally efficient and effective method to avoid the N-1 attack is investigated.