In this paper, a new combinatorial structure is introduced for image encryption, which has an excellent encryption effect on security and efficiency. An n-transversal in a Latin square has the function of classifying all the matrix’s positions, and it can provide a pair of orthogonal Latin squares. Employing an n-transversal of a Latin square, we can permutate all the pixels of an image group by group for the first time, then use two Latin squares for auxiliary diffusion based on a chaotic sequence, and finally, make use of a pair of orthogonal Latin squares to perform the second scrambling. The whole encryption process is “scrambling–diffusion–scrambling”. The experimental results indicated that this algorithm passed various tests and achieved a secure and fast encryption effect, which outperformed many of the latest papers. The final information entropy was very close to 8, and the correlation coefficient was approximately 0. All these tests verified the robustness and practicability of the proposed algorithm.

There are some good combinatorial structures suitable for image encryption. In this study, a new chaotic image encryption algorithm based on transversals in a Latin square is proposed. An n -transversal has the function of classifying all the matrix's positions, and it can provide a pair of orthogonal Latin squares. Employing an n -transversal of a Latin square, we can permutate an image data group by group for the first time, then use two Latin squares for auxiliary diffusion based on a chaotic sequence, finally make use of a pair of orthogonal Latin squares to do the second scrambling. As a whole, the encryption process of “scrambling-diffusion-scrambling” is formed. The experimental results indicate that this algorithm achieves a secure and fast encryption effect. The final information entropy is very close to 8, and the correlation coefficient is approximate to 0. All these tests verify the robustness and practicability of this proposed algorithm.

There are some good combinatorial structures suitable for image encryption. In this study, a new chaotic image encryption algorithm based on transversals in a Latin square is proposed. By means of an n-transversal of a Latin square, we can permutate an image data group by group for the first time, then use two Latin squares for auxiliary diffusion on the basis of a chaotic sequence, finally make use of a pair of orthogonal Latin squares to do the second scrambling. As a whole, the encryption process of "scrambling-diffusion-scrambling" is formed. The experimental results indicate that this algorithm achieves a secure and fast encryption effect. The final information entropy is very close to 8, and the correlation coefficient is approximate to 0. All these tests verify the robustness and practicability of this proposed algorithm.