A public key cryptosystem is a basic tool to protect data security. Most public key cryptosystem schemes include time
consuming operations such as the modular multi exponentiation. To address this problem, a new parallel algorithm for
the modular multi exponentiation is introduced. The proposed algorithm is based on parallelizing the binary method.
The experimental study on a multicore system shows that the running time of the proposed algorithm is smaller than
the previous parallel algorithm in the cases of large data sizes under diferent number of processors. The percentage of
improvement is up to 55% compared with the previous algorithm.