Optical Color Image Encryption And Hiding Technology

With the development of network, various bugs are continuously emerging in information security. Meanwhile, the demand for information security technology is growing day by day. As a core portion of information security, the image encryption and hiding technology has become an international subject of frontier. This work starts with this researching background.The main contents of this paper are as follows:(1) Based on optical information technology, the status of image encryption and hiding technique is introduced, overlooked and summarized.(2) A new method for hiding a gray image is presented. On the basis of histogram of hidden image, a gray image is divided into three gray sub-images. After being further encrypted with double-random-phase encoding, these three sub-images are hided into the R、G、B components of a color image, respectively. The experimental results show that this method possesses a good shearing resistance and anti-noise ability.(3) In order to encrypt double color images within single channel, image encryption and decryption for double color images in fractional Fourier domain is presented. Data matrices of two indexed color images are combined together by way of complex number, and then encrypted by using fraction Fourier transform, as well as double random phase encoding technique. The theoretical analysis and experimental results demonstrate that this algorithm has a high security margin.(4) A single-channel color image encryption algorithm is proposed. In the encryption process, the G component of a color image is encrypted through fractional Fourier transform and double-random-phase encryption technology. In decryption process, the R, B components of the color image are recovered by using the G component and specific phases generated via GS (gerchberg-saxton) iterative algorithm. Experimental results prove that this algorithm not only simplify an encryption system, but also keep high security in image encryption.