A Color Image Encryption and Decryption Method Based on Detour Cylinder Diffraction and Phase Preserving Truncation

Abstract

The invention provides a color image encryption method based on circuitous cylindrical diffraction and phase preservation truncation. According to the method, a complex combination of any two components in the red, green and blue components of a color image is encrypted by using the circuitous cylindrical diffraction process, two pseudo-random phase plates are respectively loaded on an object surface and an intermediate diffraction surface; the complex amplitude distribution obtained by cylindrical diffraction is separated by adopting a phase preservation truncation method to obtain an amplitude portion and a phase portion, two phase portions obtained by performing phase preservation twice serve as two decryption keys, complex combination is performed on the amplitude obtained by the firsttime of phase truncation and another component of the color image, the amplitude obtained the second time of phase truncation serve as ciphertext output. The method realizes asymmetric encryption byusing cylindrical diffraction and phase truncation, can solve three problems such as a linear system, complex value output and information leakage at the same time, and greatly improves the security of the encryption system.

Description

1. Technical Field [0001] The invention relates to the technical field of information security and information optics, in particular to a color image encryption and decryption method. 2. Background technology [0002] Science, technology, medical treatment, education and other applications produce massive amounts of color information every day. However, these massive amounts of color information face potential risks of information leakage and attacks. Therefore, the research on color image encryption and decryption is becoming increasingly important. These studies can be divided into two categories: pixel-based scrambling and transform domain-based scrambling. Since most of the scrambling of the transform domain can be realized optically, it has the huge advantage of being parallel and fast, but there are also some problems that need to be solved: 1. The linearity of the system reduces the encryption security; 2. The complex value output requires the use of holography, etc. Meth...

AI Technical Summary

Problems solved by technology

Since most of the scrambling of the transform domain can be realized optically, it has the great advantage of parallelism and high speed, but there are still some problems that need to be solved urgently: 1. The linearity of the system reduces the security of encryption; 2. Complex value output requires the use of holography, etc. method to record, which makes the system complex and has strict requirements on stability; 3. The asymmetric encryption system based on the phase truncation method also faces the risk of information leakage

Although many solutions have been proposed for the above problems, these methods only solve one or two of them

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