Image block generation from block-based SMRT in colour image encryption and its performance analysis

Abstract

The development of an efficient and fast cryptosystem has become significant with the widespread use of internet and advancements in networking technology. A colour image encryption/decryption technique using image block generation from block-based Sequency-based Mapped Real Transform (SMRT) is introduced in this paper to achieve this goal. The encryption architecture uses a confusion-diffusion approach and begins by partitioning individual colour components of plain image into fixed-size blocks. This is followed by XOR operation between generated diffusion keys and the image blocks to achieve diffusion. SMRT of the diffused image block is found and confusion induced by image block operations. Encrypted image is obtained through inverse SMRT and compilation of encrypted colour components. The proposed cryptosystem demonstrates excellent features including high sensitivity, complex keystream, strong security, high encryption and decryption efficiency and simple structure.