Flip Visual Encryption With Meaningful Shares

With the development of digital information applications,information security problems are becoming more and more significant,and the application of cryptography is more frequent.Visual encryption is an encryption algorithm of cryptography,which is easy to operate and has become a new research hot spot.After literature research and experimental analysis,the algorithm currently has the following problems:(1)The function of visual encryption algorithm does not meaningfully flip visual encryption;(2)Among the existing color visual encryption algorithms,the shared color image obtained by the meaningful color visual encryption algorithm is of poor quality and features There is no rollover visual encryption feature.In view of the above problems of visual encryption,this thesis proposes a flip visual encryption algorithm with meaningful shared images.To solve the problem(1),we propose to use the method of constrained error diffusion to embed the covered image,and then obtain a meaningful shared image.First,the shared image is divided into blocks,and the two secret images are embedded using the masking relationship between image pixels.After that,the proposed method is used to embed the masked image into the pixels of the shared image without embedded information.Furthermore,a shared image with the same visual effect as the masked image is obtained.To solve the problem(2),we apply the above gray-scale visual encryption algorithm to color images.Use color encryption model to embed secret information.First,a color visual encryption overlay method is designed according to the color model.Then use the random matrix to find the position of the embedded secret pixel and embed the information.Finally,the color shared image is divided into channels and then embedded in the masked image using the method of constrained error diffusion.Furthermore,color meaningful shared images are obtained.In order to verify the algorithm proposed in the thesis,we conducted batch experiments on grayscale and color images,respectively.Do different experiments for different images.For grayscale images,first use peak signal-to-noise ratio(PSNR)and image structure similarity(MSSIM)to analyze the quality of the image,and analyze the security of its algorithm.Then calculate the running time of the algorithm to prove the feasibility of the algorithm.For color images,contrast analysis is performed on the recovered secret image by the method of main observation evaluation,and then the running time of the algorithm is analyzed.