A fast fixed-base comb method resistant against SPA

According to the fixed-base comb method´s features, this paper apply the direct computations of 2^kP and 2P+Q to the comb method´s precomputation and evaluation stage respectively. Taking advantage of trading inversions for multiplications, the improved method is able to obtain about 73%∼83% improvement in precomputation stage and a range of 38%∼43% in evaluation stage over prime field, furthermore, our improved method is resistant to simple power analysis by pretreating the scalar k.