A comment on ''An efficient common multiplicand multiplication method to the Mon

In 2009, Wu proposed a fast modular exponentiation algorithm and claimed that the proposed algorithm on average saved about 38.9% and 26.68% of single-precision multiplications as compared to Dussé–Kaliski's Montgomery algorithm and Ha–Moon's Montgomery algorithm, respectively. However, in this comment, we demonstrate that Wu's algorithm on average reduces the number of single-precision multiplications by at most 22.43% and 6.91%, when respectively compared with Dussé–Kaliski's v