A Study Of Authenticated Image Editing Based On Digital Signatures

Digital information security is an important issue affecting national politics,economy,military,culture and social security.Digital images are important data which provide intuitive and abound of information.Digital image security is an important part of digital information security.The goal of image authentication is to detect integrity and authenticity of the image.Although traditional image authentication technology can satisfy the basic security requirements of digital images,supporting of reasonable editing is limited and can not fully release the image value.Therefore,the image authentication technology supporting reasonable editing is valuable for application.Based on two different application requirements,this paper proposes two kinds of image authentication schemes with different functionality.The main research work of this paper is as follows:First,an image editing authentication scheme(VIRCH)that can specify editing regions is proposed by using trapdoor hashing technology of cryptography combined with traditional image signature authentication technology.In VIRCH,the signer specifies editable areas of the image and generates a digital signature of the image.The editor can only modify the specified area,otherwise,the modified image will not pass verification.In addition,the editor cannot deny his or her editing.Finally,it is proved that VIRCH satisfies the security requirements of unforgeability,and the simulation of the scheme also proves the feasibility of VIRCH.Second,the Merkle Hash Tree technology of cryptography is adopted to improve the image signature authentication technology,and an image editing authentication scheme(MAMT)which can be specified by editing mode is proposed.In MAMT,the signer specifies a collection of editing operations for the image and generates a digital signature of the image.The editor can only modify the image using the editing methods in the collection,otherwise,the modified image will not pass verification.Finally,it is also proved that MAMT meets the security requirements of unforgeability,and the simulation of the scheme proves the feasibility and efficiency of MAMT.The research results of this paper enhance the editability of image authentication,improve the practicability of image editing authentication,and provide a feasible solution to the editing problem of image authentication.