Cao Yuan, Song Yinglei
School of Automation, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
Entropy (Basel). 2024 Jul 12;26(7):597. doi: 10.3390/e26070597.
Encryption of images is an important method that can effectively improve the security and privacy of crucial image data. Existing methods generally encrypt an image with a combination of scrambling and encoding operations. Currently, many applications require highly secure results for image encryption. New methods that can achieve improved randomness for both the scrambling and encoding processes in encryption are thus needed to further enhance the security of a cipher image. This paper proposes a new method that can securely encrypt color images. As the first step of the proposed method, a complete bit-level operation is utilized to scramble the binary bits in a color image to a full extent. For the second step, the bits in the scrambled image are processed with a sweeping operation to improve the encryption security. In the final step of encryption, a codebook that varies with evolutionary operations based on several chaotic systems is utilized to encrypt the partially encrypted image obtained in the second step. Experimental results on benchmark color images suggest that this new approach can securely encrypt color images and generate cipher images that remain secure under different types of attacks. The proposed approach is compared with several other state-of-the-art encryption approaches and the results show that it can achieve improved encryption security for cipher images. Experimental results thus suggest that this new approach can possibly be utilized practically in applications where color images need to be encrypted for content protection.
图像加密是一种重要的方法，能够有效提高关键图像数据的安全性和隐私性。现有方法通常通过置乱和编码操作相结合来对图像进行加密。当前，许多应用对图像加密需要高度安全的结果。因此，需要新的方法来在加密过程中提高置乱和编码过程的随机性，以进一步增强密文图像的安全性。本文提出了一种能够对彩色图像进行安全加密的新方法。作为所提方法的第一步，利用完整的位级操作将彩色图像中的二进制位充分置乱。第二步，对置乱后的图像中的位进行扫描操作以提高加密安全性。在加密的最后一步，利用基于几个混沌系统的随进化操作而变化的码本对第二步得到的部分加密图像进行加密。对基准彩色图像的实验结果表明，这种新方法能够对彩色图像进行安全加密，并生成在不同类型攻击下仍保持安全的密文图像。将所提方法与其他几种先进的加密方法进行比较，结果表明它能够提高密文图像的加密安全性。因此，实验结果表明这种新方法可能实际应用于需要对彩色图像进行加密以保护内容的应用中。
