Design And Implementation Of JPEG Image Encryption Evaluation System

Image is an important way for us to express and obtain information,the security of image transmission has become our focus,and image encryption is one of the important means to protect the security of image information.In order to reduce the amount of data stored in the image,save the network bandwidth and improve the efficiency of information transmission under the capacity of the existing communication channel,it is necessary to compress the image data.JPEG image compression is one of the widely used compression methods nowadays,and image encryption on the premise of ensuring compression ratio has also become a research focus of scholars.Various JPEG image encryption methods have been proposed,but there is no unified standard to evaluate the encryption effect of these methods,so the efficient JPEG image encryption evaluation method has become the focus of researchers.The research on the evaluation method of JPEG image encryption can optimize the parameter setting and improve the encryption scheme.It has important theoretical significance and practical value to promote the development of JPEG image encryption.In this paper,the traditional JPEG image encryption methods are classified and summarized,and two JPEG image encryption methods are proposed.Through the analysis of traditional JPEG image encryption method,if the JPEG image is encrypted by block perturbation and block mix-wash encryption algorithm,the ciphertext image obtained is vulnerable to non-zero coefficient number attack(NZCA),and the block-to-block mix-wash algorithm is robust to this attack.In this paper,a JPEG image encryption method based on Euclidean distance is proposed to evaluate the effectiveness of the method by calculating the Euclidean distance between the original image and the ciphertext image.Mixing between the block class after encryption algorithms for defect analysis,choose the plaintext attack(CPA)is combined with NZCA attack to break the cipher image.Therefore,the encryption evaluation method based on Euclidean Distance has limited evaluation on the interblock mix-wash encryption algorithm.On this basis,a JPEG image encryptionevaluation method based on Earth Mover's Distance(EMD)is proposed to evaluate the effectiveness of the encryption method by calculating the EMD Distance between the original image and the ciphertext image.