In this paper, a chaotic image encryption algorithm based on the matrix semi-tensor product (STP) with a compound secret key is designed. First, a new scrambling method is designed. The pixels of the initial plaintext image are randomly divided into four blocks. The pixels in each block are then subjected to different numbers of rounds of Arnold transformation, and the four blocks are combined to generate a scrambled image. Then, a compound secret key is designed. A set of pseudosecret keys is given and filtered through a synchronously updating Boolean network to generate the real secret key. This secret key is used as the initial value of the mixed linear-nonlinear coupled map lattice (MLNCML) system to generate a chaotic sequence. Finally, the STP operation is applied to the chaotic sequences and the scrambled image to generate an encrypted image. Compared with other encryption algorithms, the algorithm proposed in this paper is more secure and effective, and it is also suitable for color image encryption.

本文设计了一种基于带有混合密钥的矩阵半张量积（STP）的混沌图像加密算法。首先，设计一种新的加扰方法。原始明文图像的像素被随机分为四个块。然后，对每个块中的像素进行不同轮次的Arnold变换，然后将四个块组合以生成加扰图像。然后，设计复合密钥。给定一组伪密钥，并通过同步更新的布尔网络对其进行过滤，以生成真实密钥。该秘密密钥用作混合线性-非线性耦合映射晶格（MLNCML）系统的初始值，以生成混沌序列。最后，将STP操作应用于混沌序列和加扰图像以生成加密图像。与其他加密算法相比，本文提出的算法更加安全有效，也适用于彩色图像加密。