INVESTIGATION OF A NEW DIGITAL PICTURE ENCRYPTION ALGORITHM: A STATE OF THE ART SURVEY

Abstract

A new image encryption scheme using a 144-bit secret key is introduced in this paper. The image is divided into blocks and subsequently into colour components in the scheme replacement process. By conducting bitwise operations, each colour component is changed based on the secret key as well as a few most essential bits of its previous and next colour component. Three rounds are taken to complete the process of substitution. A feedback mechanism is also implemented to make the cypher more stable by changing the secret key used after each block is encrypted. In addition, the resulting image is partitioned into several dynamic sub-images based on the key. Each sub-image uses a created magic square matrix to move through the scrambling process where sub-image pixels are reshuffled within themselves. For the scrambling process, five rounds are taken. The proposed system is straightforward, quick and sensitive to the secret key. Popular attacks such as linear and differential cryptanalysis are infeasible due to the high order of substitution and permutation. The experimental results indicate that the encryption approach proposed is effective and has strong security characteristics.