A new image encryption scheme based on a hyperchaotic system & multi specific S-boxes

ABSTRACT

This paper studies a new image encryption scheme based on a hyperchaotic system & multi-specific S-boxes. First, the hyperchaotic system generates a sequence that is used to create a specific S-box. The S-box is obtained by sorting the values of the sequence of hyperchaotics of increasing sort, and then taking their index as a new sequence to create the S-box. The number of specific S-boxes needed to encrypt the image depends on the rows of the plain image. Second, each row of the plain image is substituted by a different S-box to obtain the rows of the pre-encrypted image. Third, to increase the level of security, each specific S-box is considered as a column of the mask matrix. Then, a permutation is applied to the mask matrix, which used the last sequence of the hyperchaotic to permuted the rows of the mask matrix to obtain the permuted mask matrix. Finally, the XOR operation is applied between the permuted mask matrix and the pre-encrypted image to obtain the final cipher image. Experimental and analysis results show that the proposed algorithm has a good performance in terms of security, high sensitivity, as well as low time complexity.

KEYWORDS:

• Hyperchaotic system
• permutation
• substitution-box
• image encryption