International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Yinlong Xu

Publications

Year
Venue
Title
2008
EPRINT
Complexity Analysis of a Fast Modular Multiexponentiation Algorithm
Recently, a fast modular multiexponentiation algorithm for computing A^X B^Y (mod N) was proposed. The authors claimed that on average their algorithm only requires to perform 1.306k modular multiplications (MMs), where k is the bit length of the exponents. This claimed performance is significantly better than all other comparable algorithms, where the best known result by other algorithms achieves 1.503k MMs only. In this paper, we give a formal complexity analysis and show the claimed performance is not true. The actual computational complexity of the algorithm should be 1.556k. This means that the best modular multiexponentiation algorithm based on canonical-sighed-digit technique is still not able to overcome the 1.5k barrier.

Coauthors

Haimin Jin (1)
Duncan S. Wong (1)