Hybrid chaotic virtual optical image encryption method

Abstract

The invention discloses a hybrid chaotic virtual optical image encryption method, which comprises the following steps of: 1, assuming that the size of a plaintext image is M * N, and sequentially reading pixel values of each point of the image from left to right to obtain a pixel matrix F (x, y); step 2, performing phase encoding on the plaintext image F (x, y) to obtain Q (x, y); step 2, modulating Q (x, y) through a random phase template RM1 to obtain F1 (x, y); step 3, carrying out Fourier transform on F1 (x, y), and carrying out random phase template RM2 modulation to obtain F2 (alpha, y);step 4, carrying out inverse Fourier transform on F2 (alpha beta) to obtain a ciphertext image U1; and step 5, performing secondary encryption of pixel value substitution on U1 (x, y) to obtain a ciphertext image U2. According to the invention, a coparametric generalized Fibonacci chaotic system and a coupled tent space-time chaotic system are adopted to respectively construct random templates with good uniformity; therefore, the two chaotic systems have a linkage effect, the defect that the distribution of random template elements constructed by the Logistic chaotic system is not uniform isovercome, and the hiding property on a ciphertext and the sensitivity on a secret key are enhanced.

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

Images