Improving One-Time Pad Algorithm on Shamir’s Three-Pass Protocol Scheme by Using RSA and ElGamal Algorithms

Abstract

This study aims to cover the shortcomings of the one-time pad algorithm used in the Shamir’s three-pass protocol scheme. In this study, the technique used to cover the weakness of one-time pad algorithm is by changing each ciphertext generated from the three paths in the three pass protocol scheme. Ciphertext modification is performed by encrypting the cipher-text by using the RSA and Elgamal algorithms to generate super ciphertext. The first line and the third line are encrypted by using the RSA algorithm and the second line is using ElGamal algorithm. Both algorithms are aimed at keeping no secret key exchange which is a major requirement of the three pass protocol scheme. The evaluation results show that the weakness of one-time pad algorithm can be overcome. Although the processing time of three pass protocol increases, but the longer the plaintext character the closer the processing time ratio to one. The research showsThe only way for plaintext to be formed by cryptoanalysis is they must succeed to decrypt the three super ciphertexts back into the three initial ciphertexts first. But it is not easy if RSA and ElGamal algorithms use the big prime number.