Appl Opt. 2021 Aug 1;60(22):6511-6519. doi: 10.1364/AO.425776.
We present an asymmetric encryption scheme for hyperspectral images using hybrid chaotic maps (HCMs) and an equal modulus decomposition tree (EMDT) structure in a discrete multiple-parameter fractional Fourier transform (dmpFrFT) domain. The original hyperspectral image was scrambled by an HCM and then encrypted into asymmetric ciphertext using the EMDT. In the EMDT, each pair of the band images of the scrambled hyperspectral image were regarded as leaf nodes, while the encryption modules using chaotic random phase mask, dmpFrFT, and improved equal modulus decomposition were regarded as branch nodes, and the encryption process was implemented along the paths from the leaf nodes to the topmost branch node. The EMDT structure could provide multiparameter encryption, real-valued output, and different pairs of band images with different secret keys and encryption/decryption paths. Compared with the previous optical encryption approaches for hyperspectral images, our asymmetric cryptosystem had larger key space, less data amount of storage and transmission, and stronger resistance to statistical attacks. Various numerical simulations verified the performance of our proposed asymmetric cryptosystem.
我们提出了一种使用混合混沌映射（HCM）和等模数分解树（EMDT）结构在离散多参数分数傅里叶变换（dmpFrFT）域中的高光谱图像的非对称加密方案。原始高光谱图像通过 HCM 进行置乱，然后使用 EMDT 加密成非对称密文。在 EMDT 中，每个 scrambled 高光谱图像的波段图像对都被视为叶节点，而使用混沌随机相位掩模，dmpFrFT 和改进的等模数分解的加密模块被视为分支节点，加密过程沿着从叶节点到最顶层分支节点的路径进行。EMDT 结构可以提供多参数加密、实值输出以及不同密钥和加密/解密路径的不同波段图像对。与以前的高光谱图像光学加密方法相比，我们的非对称加密系统具有更大的密钥空间、更少的数据存储和传输量以及更强的抗统计攻击能力。各种数值模拟验证了我们提出的非对称加密系统的性能。
