Image Encryption based on Pseudo Hadamard Transformation with Constant Co-efficient

Abstract

In this paper, transformation and non-chaotic substitution based image cryptosystem has been proposed. The transformation phase involves 2-D Pseudo Hadamard Transform with constant co-efficient (PHTC) and substitution is performed using S-box with 128 bits of secrete key. Due to two stage encryption process, the strong correlation between adjacent pixels is effectively reduced and high entropy is observed in the cipher image. The cipher image is imperiled for several security analysis and the result proves strong resistivity against differential attacks. Even though the algorithm encrypts image in two stages, utilizes very less execution time. The results attained are relatively better compared to other prevailing algorithms.