Huo Dongming, Zhu Zhilong, Zhou Xin, Wei Lisheng, Bai Xing, Bai Yanzhi, Han Chao
Key Laboratory of Advanced Perception and Intelligent Control of High-End Equipment, Ministry of Education, College of Electrical Engineering, Anhui Polytechnic University, Wuhu 241000, China.
Department of Opto-Electronics Science and Technology, Sichuan University, Chengdu 610065, China.
Heliyon. 2023 Feb 27;9(3):e14072. doi: 10.1016/j.heliyon.2023.e14072. eCollection 2023 Mar.
Encrypting plain images into noise-like cipher images is a common method in image encryption. However, when noise-like images appear in public networks, they are more likely to attract attention and suffer more cryptanalysis. To solve this problem, researchers propose the concept of visually meaningful image encryption scheme, which encrypts a plain image into a visually meaningful cipher image. In order to realize the visual security of cipher image and increase information capacity, this paper proposes a flexible visually secure multi-image compression, encryption and hiding scheme based on two-dimensional compressive sensing (2DCS), which can flexibly complete the compression and encryption of multiple plain images without increasing the amount of ciphertext data. The scheme is divided into encryption process and embedding process. In the encryption process, the plain image is randomly scrambled and non-linear gray value transformed to obtain a pre-encrypted integer matrix, then 2DCS is used to compress the pre-encrypted integer matrix to get the secret image. Repeat this process for multiple plain images to obtain multiple secret images. In the embedding process, integer wavelet transform and bit-plane decomposition are used to embed multiple secret images into the quantized coefficient matrix of host image to get the modified coefficient matrix, and then the inverse integer wavelet transform is used to transform the modified coefficient matrix into spatial space to get the visually meaningful cipher image. The simulation experiment verifies the feasibility and effectiveness of the visually meaningful multi-image encryption scheme, and users can choose to improve the system's encryption capacity or cipher image's visual security according to their own needs.
将普通图像加密为类似噪声的密文图像是图像加密中的一种常见方法。然而，当类似噪声的图像出现在公共网络中时，它们更容易引起注意并遭受更多的密码分析。为了解决这个问题，研究人员提出了视觉上有意义的图像加密方案的概念，即将普通图像加密为视觉上有意义的密文图像。为了实现密文图像的视觉安全性并增加信息容量，本文提出了一种基于二维压缩感知（2DCS）的灵活的视觉安全多图像压缩、加密和隐藏方案，该方案可以在不增加密文数据量的情况下灵活地完成多个普通图像的压缩和加密。该方案分为加密过程和嵌入过程。在加密过程中，对普通图像进行随机置乱和非线性灰度值变换，得到预加密整数矩阵，然后用2DCS对预加密整数矩阵进行压缩得到秘密图像。对多个普通图像重复此过程以获得多个秘密图像。在嵌入过程中，使用整数小波变换和位平面分解将多个秘密图像嵌入到宿主图像的量化系数矩阵中得到修改后的系数矩阵，然后用整数小波逆变换将修改后的系数矩阵变换到空间域得到视觉上有意义的密文图像。仿真实验验证了视觉上有意义的多图像加密方案的可行性和有效性，用户可以根据自身需求选择提高系统的加密容量或密文图像的视觉安全性。
