Image encryption by AES algorithm based on Chaos-Permutation

Abstract

Today, in particular with the development of the internet, transmitting confidential information in a secure manner has become a basic need; data encryption is often the only effective way to meet these requirements. Traditional cryptography is the study of methods for transmitting confidential data; in modern cryptography, transformation is applied to the plain message that makes it incomprehensible; these transformations are mathematical functions, called cryptographic algorithms, which depend on a parameter called key. In this paper, we presents a new symmetrical crypto-system by block for encrypting images on using the encryption AES algorithm (Advanced Encryption Standard) combined with the CBC mode (Cipher Block Chaining) in order to improve the security level. The proposed crypto-system consists on replacing the linear permutation of ShiftRows step of the AES encryption algorithm by a nonlinear and random permutation, this permutation is calculated by a chaotic sequel.