Scalable optical image encryption method based on cylindrical diffraction and phase truncation

Abstract

The invention provides a scalable optical image encryption method based on cylindrical diffraction and phase truncation. The method decomposes an image into a plurality of high-frequency components and a low-frequency component by using discrete wavelet transform, wherein two components are respectively used as a real part and an imaginary part each time and are superposed to form complex amplitude. The encryption random phase plate is loaded on an object plane, after cylindrical diffraction, a single-amplitude ciphertext is obtained through asymmetric operation of phase truncation, and operation is repeated to obtain a final real-value ciphertext. The method has the advantage of scalability, and different encryption effects can be obtained by selecting different modes so as to meet the requirements of different encryption scenes. In addition, the method can resist the phase recovery attack, can prevent information leakage, and has high security. Numerical simulation proves the safetyand effectiveness of the method.

Description

technical field [0001] The invention relates to the technical fields of information security and information optics, in particular to an optical image encryption method. Background technique [0002] The application research of dual random phase encoding technology and optical interference theory in image encryption is a hot topic in the field of optical information security research in recent years. In 1995, Javidi of the United States first proposed the dual random phase encoding technology based on the 4-f system, which became a widely used optical encryption technology. However, some studies have shown that the DRPE encryption method is a linear symmetric encryption system, which cannot effectively resist various attacks. Therefore, asymmetric encryption methods such as phase truncation are introduced to improve the anti-attack capability of this type of encryption method, but at the same time, it causes the problem of information leakage that can be partially decrypted...

AI Technical Summary

Problems solved by technology

Although previous studies have greatly improved the security of encryption systems, a novel asymmetric encryption system based on phase truncation is still needed to solve the problems of information leakage and phase recovery attacks.

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