ABSTRACT A nonlinear image encryption and authentication strategy based on phase truncation and reservation (PTR) in cylindrical diffraction domain is proposed. First, the cylindrical diffraction spectrum of the input image is sparsely sampled. Then, its sparse presentation is disintegrated into phase part and real-valued amplitude part with the help of the PTR, both of which are essential for decryption and authentication. The decrypted image reveals little information of the original input image visually. Finally, a nonlinear correlation is resorted to authenticate the decrypted image with the input image. In the proposed strategy, the parameters of cylindrical diffraction are utilized to enhance its security. The cylindrical diffraction has the nonlinear characteristics, while the PTR outputs real-valued cyphertext, which further breaks the linearity. Furthermore, the percentage of extracted pixels in sparse sampling needs not to be identified purposely. Numerical simulations demonstrate the feasibility and effectiveness of the proposed scheme.

中文翻译：

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柱面衍射域中基于相位截断和保留的非线性图像加密与认证

摘要 提出了一种基于柱面衍射域相位截断和保留(PTR)的非线性图像加密和认证策略。首先，对输入图像的柱面衍射光谱进行稀疏采样。然后，在 PTR 的帮助下，将其稀疏表示分解为相位部分和实值幅度部分，这两者对于解密和认证都是必不可少的。解密后的图像在视觉上揭示了原始输入图像的很少信息。最后，采用非线性相关性来验证解密图像与输入图像。在所提出的策略中，利用柱面衍射的参数来提高其安全性。柱面衍射具有非线性特性，而PTR输出实值密文，这进一步打破了线性。此外，不需要特意识别稀疏采样中提取像素的百分比。数值模拟证明了所提出方案的可行性和有效性。