| Recent years,with the development of technology,the speed of updating digital products are getting faster and faster.The openness of the network and the improving of the computing power which makes the convenience of exchanging and transporting digital products.Digital product transmission technology has reached to all aspects of people's learning,work and life.On the one hand,it provides convenience for people's life and work,but on the other hand,it makes digital information easy to copy,steal and tamper.Therefore,the information security issues are becoming more and more important,especially in some special areas,such as digital management of medical images.With the development of modern medicine,doctors' diagnosis work is increasingly dependent on modern examination results,and medical imaging has become an indispensable part.Network-based remote transmission and storage systems can make medical information applications and communication convenient and fast,but also can be easily attacks or tampering;As for the important part of diagnosis basis,if medical images spread on the public network,more attention is needed to prevent patient's sensitive information from being illegally leaked,which makes the authenticity authentication of medical images very important.Medical images have the characteristics of high resolution,high precision,large data volume,etc.The medical images need to be encrypted to protect the confidentiality of medical images,and digital watermarking techniques are also needed for medical images to ensure the authenticity and integrity of the images.Therefore,it is necessary to combine the two technologies,which can not only protect the confidentiality of medical images,but also can fully protect the authenticity of medical images.This paper systematically studies the theory and development of image encryption,information hiding and watermark authentication technology,and propose an identifiable tampering image encryption algorithm based on chaotic double watermark and compressed sensing.(1)In terms of protecting user data security,this paper adopts a method about data encryption during transmission.In order to solve the problem of energy saving and safety,we avoided the traditional two-step method of "first to compression and second to encryption".We adopted the theory of compressed sensing proposed by Zhexuan Tao in 2006,and implemented compression and encryption in the same time.Compressed sensing has been widely used in many fields as soon as it is proposed.The encryption scheme of this paper uses chaotic compressed sensing to enhance the security of transmission through two chaotic matrices,and it saves storage space by using chaotic initial values,parameters and sampling parameters,which has better security performance while saving energy.In this paper,the encryption performance is analyzed in detail in terms of encryption histogram,adjacent pixel correlation and peak signal-to-noise ratio(PSNR).It is proved that the improved chaotic compression sensing proposed in this paper has good performance and application value for image encryption.(2)In terms of protecting data authenticity,digital watermarking is required after encryption.The watermarking content comes from the image itself and the feature information hides two copies in the image through the form of watermarking.If tampering is experienced during image transmission,the watermarking algorithm can locate tampering and restore tampering to ensure the authenticity of the medical image.Compared with the traditional algorithm which only encrypts during transmission,it can resist some attacks.In order to ensure the encryption effect,such method can effectively restore the important information that has been tampered in the image,which can compensate the only encryption technology.This paper evaluates the effect of tampering recovery from qualitative and quantitative perspectives.Promising results show the effectiveness of the proposed method in medical and other images. |
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