Research Into The Security Protocols Based On Digital Signature In Electronic Commerce

With formal implementation of "Electronic Signature Law", the digital signature is going to be widely applied in electronic commerce. Protocols are technical foundation to carry out digital signature in electronic business, so the protocols compatible with digital signature must be perfected.According to Dolev-Yao model, this paper separates protocol and cryptographic arithmetic into two levels. Researches into authentication protocols, no-repudiation protocols, forward-secure and confirmer signature protocols based on digital signature are carried out on protocol level.The main aspects of this work are shown hereinafter.Firstly, the primary threats on protocols based on digital signature are pointed out, such as imitation and replay. The existing cases with bugs are analyzed. Several security guide -lines are summarized for designing and analyzing protocols based on digital signature.Secondly, three-way authentication protocols of X.509 standard and authentication protocols of SSL are discussed. The bug hidding behind random number is shown clearly. A new authentication protocol is proposed, whose security is independent from that of used random number. BAN Logic is applied to prove it.Thirdly, the concepts and properties of non-repudiation protocols are elaborated. The main points here are: TTP (Trusted Third Party) is adopted as main mode to implement non-repudiation protocols, for non-repudiation protocols fairness is the principal property, and "one-to-one " pattern is the basic one. The protocols proposed by Qing Sihan and Li xianxian are reviewed respectively, and then some shortages and limitations of such protocols are discussed. A new non-repudiation protocol is recommended, subsequently, its security, fairness, accountability, etc. are analyzed. SVO Logic is applied to verify them.Fourthly, the concepts and related works of forward-security and comfirmer signature are addressed. Two limitations are pointed out: one is that the existing schemes integrate protocol with cryptographic arithmetic closely on the same level.as makes them so complicated that they could hide troubles; the other is that the whole system has to keep high accuracy of clock coincidence for ensuring forward-security, as is a difficul target to reach. A new forward-security and comfirmer signature protocol is suggested on protocol level. The new protocol is compact and clear, whose signature confirmation is zero-knowledge proof. It can prevent verifier from transferring proof or simulating confirmation by himself. It also has the characters of non-visibility and security, which comfirmer signature should possess.SVO Logic is applied to prove it again. Two simplified schemes are given.Finally, two directions on security protocol research are pointed out: research on practical protocols and formal methods for the analysis of security protocols. Further work will be oriented towards these two directions.