Subathra S, Thanikaiselvan V
School of Electronics Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu, India, 632014.
Sci Rep. 2025 Jul 2;15(1):22628. doi: 10.1038/s41598-025-04906-4.
Medical image encryption is important for maintaining the confidentiality of sensitive medical data and protecting patient privacy. Contemporary healthcare systems store significant patient data in text and graphic form. This research proposes a New 5D hyperchaotic system combined with a customised U-Net architecture. Chaotic maps have become an increasingly popular method for encryption because of their remarkable characteristics, including statistical randomness and sensitivity to initial conditions. The significant region is segmented from the medical images using the U-Net network, and its statistics are utilised as initial conditions to generate the new random sequence. Initially, zig-zag scrambling confuses the pixel position of a medical image and applies further permutation with a new 5D hyperchaotic sequence. Two stages of diffusion are used, such as dynamic DNA flip and dynamic DNA XOR, to enhance the encryption algorithm's security against various attacks. The randomness of the New 5D hyperchaotic system is verified using the NIST SP800-22 statistical test, calculating the Lyapunov exponent and plotting the attractor diagram of the chaotic sequence. The algorithm validates with statistical measures such as PSNR, MSE, NPCR, UACI, entropy, and Chi-square values. Evaluation is performed for test images yields average horizontal, vertical, and diagonal correlation coefficients of -0.0018, -0.0002, and 0.0007, respectively, Shannon entropy of 7.9971, Kolmogorov Entropy value of 2.9469, NPCR of 99.61%, UACI of 33.49%, Chi-square "PASS" at both the 5% (293.2478) and 1% (310.4574) significance levels, key space is 2 and an average encryption time of approximately 2.93 s per 256 × 256 image on a standard desktop CPU. The performance comparisons use various encryption methods and demonstrate that the proposed method ensures secure reliability against various challenges.
医学图像加密对于维护敏感医学数据的保密性和保护患者隐私至关重要。当代医疗系统以文本和图形形式存储大量患者数据。本研究提出了一种结合定制U-Net架构的新型5D超混沌系统。由于混沌映射具有显著特性,包括统计随机性和对初始条件的敏感性,它已成为一种越来越受欢迎的加密方法。使用U-Net网络从医学图像中分割出重要区域,并将其统计信息用作初始条件来生成新的随机序列。首先,之字形置乱混淆医学图像的像素位置,并使用新的5D超混沌序列进行进一步置换。采用动态DNA翻转和动态DNA异或等两个扩散阶段,以增强加密算法抵御各种攻击的安全性。使用NIST SP800-22统计测试验证新型5D超混沌系统的随机性,计算李雅普诺夫指数并绘制混沌序列的吸引子图。该算法通过PSNR、MSE、NPCR、UACI、熵和卡方值等统计量进行验证。对测试图像进行评估,得到的平均水平、垂直和对角线相关系数分别为-0.0018、-0.0002和0.0007,香农熵为7.9971,柯尔莫哥洛夫熵值为2.9469,NPCR为99.61%,UACI为33.49%,在5%(293.2478)和1%(310.4574)显著性水平下卡方检验均为“通过”,密钥空间为2,在标准桌面CPU上每256×256图像的平均加密时间约为2.93秒。性能比较使用了各种加密方法,结果表明所提出的方法能够确保在面对各种挑战时的安全可靠性。