Fair And Non-repudiation Protocol Design And Formal Analysis

Fair and non-repudiation protocols ensure communication parties's non-denial for their actions and ensure their fairness. These protocols which are the base of e-commerce protocols ensure that both parties receive their messages and evidences or both receive nothing. Because of the importance of fair and non-repudiation protocols, the design and security analysis are very popular in information security field during recent decade. Currently, there are many formal analysis methods to analyse these protocols. The paper mainly discusses the methods based on logic reasoning.Forward security is another important concept in security field. It mainly based on the below idea. If a user's private key compromises, other parties could obtain former signature or forge new signature. This results in non-repudiation problem. So it is very important how to design a fair non-repudiation protocol based on forward security. The paper mainly discusses the protocol proposed.The main job is as follow:①First, the paper introduces fair and non-repudiation protocols and security protocol formal analysis methods.②Second, the paper discusses some basic problems in the formal analysis of fair non-repudiation protocols,such as cipher technology, concept and classify, basic hypothesis and security property, and design method and principle. The paper also discusses familiar attacks and forward security property.③Third, the paper analyses the popular protocol---CMP1 protocol(Certified electronic mail 1)[1]and finds there are some faults in CMP1 protocol. By introducing random number,the CMP1 protocol is improved. The new protocol has many kinds of merits of many protocols and achieves basic security properties, such as non-repudiation, fairness, secrecy and efficiency.④Fourth, the paper analyses the protocol---DKNRP protocol(double-encrypted key non-repudiation protocol) [2] using attack methods. The result indicates the protocol can not resist the playback attack. So a new fair non-repudiation protocol based on email is put forward. At last, SVO logic reasoning methods are used to analyse the new protocol. The results indicate that the new protocol satisfies non-repudiation and fairness properties.⑤At last, a security email protocol based on time using primary signature mechanism is designed,which ensure that if signature private key exposures, other parties can not forge signature or can not obtain former signature. What's more, the protocol doesn't need lookup CA revoke list and can verify signature validity.