The Design And Realization Of A Strong Proxy Signature Against DLC Attack

The information security has become more and more crucial with the development of computer and network technologies. The digital signature is one of key techniques in information security, especially in the authentication, data integrity, and non-repudiation.It has been widely used in military, communication, e-commerce and e-government, etc.and will become more and more popular after the e–signature law is put in practice.the main interest of this dissertation is on the theory and method of digital signature and its application.The research focuses on some key problems digital signature.First of all,the thesis introduces several famous proxy digital signature schemes,etc MUO,PH,KPW,LKK and so on, analyses the merits and demerits of each schemes,compares the signature efficiency and security traits and proposes the Lkk scheme is not security because the data between the poxy signer and original signer is vunerable to DLC attack.So the security transport channels must be established between the poxy signer and original signer.Secondly, a new strong proxy signature scheme is proposed aiming at the DLC attack in B.Lee's scheme, we prevent the original signer's DLC attack with inversion operation of the proxy signer's private key, change linear operation to DLP against the original signer's DLC attack, increase the complexity of proxy private key, and make it impossible to delete his/her private key with DLC attack. So the original signer cann't forge a signature or impose it on the proxy signer. Our revised scheme improves the security and efficiency.Thirdly, this thesis briefly introduces the public key infrastructure (PKI),by analyzing PKI,CA and strong proxy signature,the fundamental model of the strong proxy signature system is proposed.The strong proxy signature system against DLCattack is designed and the function of every module is introduced.The strong proxy signature system against DLC attack is implemented by the single computer simulation,This thesis tests the system's efficience and proves the feasibility of the system, So it has some practical guidance for the implementation of network security work.Finally, the thesis introduces the strong proxy signature's application on mobile agents,e-commerce,e-government,e-vote,e-cash and so on, and analyses the weakness and development trend in the future, and points that we must improve some key technology of the strong proxy signature about againting attack,forging signature and improving security communication channels.