Cryptography of medical Images using Hybrid Advanced Encryption System and Cat Map Algorithm

Abstract

Cryptography is the technique of hiding message or secret writing. Encryption is one of the features of cryptography in which one hides information or data by changing it into transformation. The transformed data is in the form of cipher data which will be not understand by third person. Many image encryption algorithms and techniques have been proposed with their performance and limitations. In this work, an image encryption algorithm based on chaotic based AES algorithm is proposed. The AES algorithm used in this work is 512 bit model. The state is a rectangular array of bytes and hence the length of block is 512 bits that was 64 bytes, the dimension of rectangular array 8x8 was used to store these 64 byte values. Hence the objective is to deploy the AES algorithm with the extended key length of 512 bits and an extended number of rounds to process the input data. The combination of AES algorithm and Cat chaos mapping is proposed to provide efficient security and speed aspects in performance. The results demonstrate that the proposed method validates the performance based on the significant changes in the image with encryption. The results are evaluated with NPCR and UACI estimation and the computational time is calculated.