Image Encryption / Decryption System based on Permutation and Blowfish Algorithm

Abstract

Internet and networks applications are growing very fast , so the needs to protect such a applications are increased. Data encryption / decryption is used to securely transmit data in open networks . Each type of data has its own features , therefore, different techniques should be used to protect confidential image data from unauthorized access. This system presents a new permutation technique based on the combination of image permutation and a well known encryption and decryption algorithm called Blowfish ,a symmetric block cipher. Blowfish is a fast cryptographic software algorithm, using the operations of addition, XOR and look-up tables. In addition, Permutation process is also added in this system to be difficult predicting the value of pixel from the values of its neighbors. In this system, the original image is divided into 4 pixel × 4 pixels blocks, which are rearranged into a permuted image using a permutation pro Blowfish algorithm .