An image encryption scheme based on constructing large permutation with chaotic sequence

• Introduced the combination operation on permutations and proved its properties.
• Proposed an effective method to generate large permutation based on combination.
• Proposed an image encryption scheme based on large permutation and diffusion.
• The proposed encryption scheme has high security and significant speed advantage.

This paper proposes a chaos-based image encryption scheme with a permutation–diffusion structure. In the proposed scheme, the large permutation with the same size as the plain-image is used to shuffle the positions of image pixels totally. An effective method is also presented to construct the large permutation quickly and easily by combining several small permutations, where small permutations are directly generated using a chaotic map. In the diffusion stage, the pixel is enciphered by exclusive or with the previous ciphered pixel and a random number produced by the Logistic map with different initial conditions. Test results and analysis by using several security measures have shown that the proposed scheme is efficient and reliable, and can be applied to real-time image encryption.

Figure optionsDownload as PowerPoint slide