Research On Arnold Scrambling Transform Image Encryption Algorithm

Digital image can give people intuitive visual experience,at the same time,it can also provide a lot of information.As an information carrier,digital image has become an important means for people to get information in daily life.In some areas related to security and secrecy,image is an important way of information transmission.In order to ensure that the image information is not tampered or stolen artificially,and the information is delivered safely,the efficient image encryption algorithm is indispensable.This paper chooses Arnold transform scrambling encryption algorithm to study research.This algorithm is a kind of algorithm of scrambling pixels in the spatial domain,which can simply and effectively protect information,and occupy a prominent position in the field of image encryption.In order to improve the encryption performance of Arnold transform and improve the encryption effect and improve the encryption security,this paper proposes an improved encryption algorithm based on Arnold transform,the main work is as follows:(1)Research on common scrambling encryption algorithm,and focuses on the basic characteristics of the Arnold transform algorithm.The transformation formulas,inverse transformation and periodicity of two-dimensional equilateral and non-equilateral Arnold transformation are described in detail.The shortcomings of existing algorithms in different types of image encryption are analyzed,The verification and improvement are carried out.(2)An Arnold transform image encryption algorithm based on random point-blocking is proposed.Aiming at the deficiencies of the existing block image encryption algorithm in image segmentation algorithm,a block extraction algorithm based on random point selection is proposed.The algorithm can divide the image into several square and non-squares blocks,extending the scope of application of the algorithm.Then,two-dimensional equilateral and non-equilateral Arnold transformation are used for each block.,the improved algorithm improves the encryption performance of the Arnold transform and is suitable for image encryption of any size.(3)An improved image encryption algorithm combining bit operation is proposed.The Arnold transform is an algorithm for spatial location scrambling of pixels.This algorithm does not affect the values of pixels within the image.The grayscale histograms of the encrypted image and the original image are consistent.In order to make up for this deficiency,bit-exclusive OR operations and bit plane swapping operations are used to change the values of pixels in the image,thereby changing the distribution of the grayscale histogram.The experimental results show that the research and improvement of Arnold transform in this paper are effective for encrypting any size image.Intuitively,the encrypted image is the same as the noisy image;The diversity of Arnold transformation matrix and period in the improved algorithm ensures the security of encrypted information;The encrypted image has good anti-attack ability and the correlation between pixels is greatly reduced.