A new color image cryptosystem via hyperchaos synchronization

• A new color image cryptosystem based on hyperchaos synchronization is proposed.
• The presented color image encryption algorithm is a symmetric cryptosystem.
• The encryption method combines pixel-value substitution and pixel-position permutation.
• The proposed cryptosystem has higher security.
• The proposed cryptosystem is robust against noise and crop attacks.

This paper proposes a novel color image cryptosystem based on synchronization of two different six-dimensional hyperchaotic systems. In the transmitter end, we apply the drive system to generate the diffusion matrices and scrambling ones, which are used to change the image pixel value and position, respectively. Thus the ciphered image is obtained. In the receiver, synchronization of two nonidentical hyperchaotic systems can be achieved by designing the appropriate controllers. The response system is employed to yield the corresponding diffusion matrices and scrambling ones using the same generation method in the encryption algorithm. Then the cipher-image can be decrypted by the decryption algorithm, which is similar to that of the encryption process but in the reversed order. The experimental results show that the presented image cryptosystem has high security and can resist noise and crop attacks.