Research On Information Security Theory And Technology Of Networked Menufacturing

Networked manufacturing system is constructed by using advanced network technology, manufacturing technology and other related technology to fit the special needs of manufacturing. It is of great importance to research on information security problems in the networked manufacturing system such as fair digital signatures on digital contracts between enterprises, the identity authentication between enterprises, the identity authentication in cooperation design system and the documents secure transforming in network setting, so to design solution schemes aimed at those information security problems for the networked manufacturing system is of both practical and theoretical importance.In this doctoral dissertation, based on analyzing the security characteristic and the security demand of the networked manufacturing system, the information security problems in the networked manufacturing system are studied deeply and feasible solution aimed at these problems are presented. The main research results are as follows:Aimed at the fair exchange problem of digital contract signatures between enterprises in networked manufacturing, based on analyzing the security flaws in existing concurrent signatures scheme, two digital signature protocols to fit the demand of fair exchange of the digital contract are presented, named i2PCS1 and i3PCS1. The characteristic of the i2PCS1 protocol is that the content of the contract is bound with the key stones to form the key stone fix to prevent the message substitute attack efficiently. The distinct advantage of i3PCSl protocol is that its keystones are published by the leaguer member. This characteristic make the leaguer member enterprise has some advantage over the hegemonic enterprise in this protocol to counteract advantage hold by hegemonic enterprise in cooperation and make the protocol has more impartiality. The new protocol is an efficient security scheme for digital contract signatures between enterprises in networked manufacturing system. Aimed at the problem of time authentication in digital signature, time-stamp scheme is studied. The new time-scheme supply a feasible method for the time authentication of the digital contract signatures.Aimed at the problem of the identity authentication in dynamic enterprises alliance, based on analyzing the security flaws in member joining and quitting protocol of existing interactive authentication scheme for virtual enterprises, an improved interactive authentication scheme against collusion attack for virtual enterprises is proposed. By assigning an important parameter as partial private key to the hegemonic enterprise in virtual enterprises, the hegemonic enterprise is required to take part in the private key generation and certificate issue for the Virtual Certificate Authority (VCA) in the new scheme. The new scheme not only maintains the excellence that leaguer members'share set can be assigned flexibly, but also remedies the security flaw in the existing interactive authentication scheme for virtual enterprises.Aimed at the special situation which several designer may collaborate to finish a designing work in networked manufacturing system, two signature schemes for coordinated design are proposed. The one is an efficient security multi-signature scheme, which is conformable for the situation that many designers sign one document together; and another one is multi-signers strong designated verifier signature scheme which is conformable for the situation that many designers sign one document together and assign an exclusive verifier who can verify the signature. These new schemes supply effective approach for document collaborative signatures in networked manufacturing system.Aimed at the confidentiality requirement of information transfers in collaborative design system, a certificateless broadcast encryption scheme based on design team is presented. Based on designer's identity and the design team's identity, the new scheme offers an efficient encryption mechanism and decryption mechanism on the level of design team. The new scheme belongs to certificateless broadcast encryption; the private key escrow problem in ID-based public key system is solved. So it is fit for the confidentiality requirement of information transfers in collaborative design system including many design teams. The new scheme doesn't need the public key infrastructure (PKI), so it is fit for small middle enterprises for its low cost, high security and efficiency.Based on the theory of information security, a document management platform is designed with B/S architecture model and Spring framework. In the security scheme of this system, the sanitizable digital signature technology "PIATS" is used to documents in VRML format, the authentication of partial file is realized without the whole file being demonstrated, the contradiction between invisibility and integrity is solved.