A Hybrid Chaotic Virtual Optical Image Encryption Method

Abstract

The invention discloses a hybrid chaotic virtual optical image encryption method. The method includes the following steps: Step 1. Assuming that the size of the plaintext image is M×N, read the pixel values ​​of each point of the image sequentially from left to right to obtain its Pixel matrix F(x, y); Step 2: Perform phase encoding on the plaintext image F(x, y) to obtain Q(x, y); Step 2: Modulate Q(x, y) with a random phase template RM1 to obtain f 1 (x,y); Step 3, F 1 (x, y) undergoes Fourier transform and undergoes random phase template RM2 modulation to obtain F 2 (α, β); Step 4, F 2 (α, β) undergo inverse Fourier transform to obtain the ciphertext image U1; Step 5, perform secondary encryption on U1(x, y) with pixel value replacement to obtain the ciphertext image U2. The present invention adopts the common parameter generalized Fibonacci chaotic system and the coupling tent space-time chaotic system to respectively construct random templates with good uniformity, so that the two chaotic systems have a linkage effect, which makes up for the shortcomings of uneven distribution of random template elements in the Logistic chaotic system, and enhances The concealment of ciphertext and the sensitivity of key.

Description

technical field [0001] The invention relates to a virtual optical image encryption method, in particular to a hybrid chaos virtual optical image encryption method. Background technique [0002] As a carrier, images contain a lot of information, and their security is very important. Virtual optical image encryption (VOIE) not only has the advantages of high-dimensional space and multiple degrees of freedom of optical methods, but also has the advantages of computer information security technology, and has become a hot topic for scholars to study. In 1995, Refregier and Javidi proposed the 4f encryption system, which is the most representative. The system uses two random templates as keys to increase the key space. In 2007 Peng pointed out the vulnerability of the system to known-plaintext, chosen-plaintext and ciphertext-only attacks. Then the method was extended to encryption systems based on fractional Fourier transform, Fresnel transform, and computational holography. ...

AI Technical Summary

Problems solved by technology

The nonlinear function in the chaotic model adopts Logistic mapping in the real number field, which has the characteristics of uneven distribution and has potential safety hazards

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