Image Encryption by Novel Cryptosystem Using Matrix Transformation

Abstract

The Hill cipher is a famous symmetric cryptosystem that have several advantages in data encryption. However, the Hill cipher algorithm cannot encrypt images that contain large areas of a single color. Thus, it does not hide all features of the image which reveals patterns in the plaintext. Moreover, it can be easily broken with a known plaintext attack revealing weak security. In this paper, novel cryptosystem is used to encrypt image that overcomes these disadvantages. The novel cryptosystem uses randomly generated self-invertible matrix as an encryption key for each block encryption and also this method eliminates the computational complexity involved in finding inverse of the matrix while decryption. The proposed variant yields higher security and significantly superior encryption quality compared to the original one.