A combination of vigenere algorithm and one time pad algorithm in the three-pass protocol

Universitas Sumatera Utara, Departemen Ilmu Komputer, Fakultas Ilmu Komputer dan Teknologi Informasi, Jl. Universitas No. 9-A Medan 20155, Indonesia

^* Corresponding author: dian.rachmawati@usu.ac.id

Abstract

Cryptography is the method of delivery of messages in secret, thus only the intended message recipient can read the message. In this study, the cryptographic algorithms which used are Vigenere Cipher and One Time Pad. However, the security of both algorithms depends on the security of the algorithm key. Three-Pass Protocol is a scheme of work that lets two people exchange secret messages without doing a key exchange. So, both the symmetric cryptographic algorithms combined on a Three-Pass Protocol scheme. The purpose of the combination of two algorithms in the three-pass protocol is to secure the image message without exchange key process between sender and recipient. The results of the research and testing using GetPixel pointed out that safeguarding the image file using the combination of Vigenere Cipher and One Time Pad algorithm restores the original image files intact. Therefore, it meets the parameters of the integrity of the data. The test results based on time parameter shows that time of the program execution process is directly proportional to the size of the image. The result is related with the formula which calculate every pixels of the the image.