Design And Implementation About Digital Seal System For Public Document

With the development of E-commerce and E-government,more and more electronic documents appeared,It is a new problem to use tradition seal effectively in paperless work.At the same time,It becomes so important to store,protect and verify the data of the date and time which takes place when electronical documents are produced,exchanged and signed.Along with our country "Electronic Signature Law" implernentation,more an more digital seal systems appearance.The digital seal is carrier to perform the functionality of the traditional seal in electronical document.It implements the document's authority and make documents not copyed.Users cann't deny what they signed.besides,it uses advanced computer technology to eliminate the security problem of traditional seals,such as careless keeping.With the support of the project "The application and research of pictorial information fusion technology based on USB technology"(Project serial number (2005C31010)) from Science Bureau of Zhejiang Province,we have analyzed the basic schemes of digital seal in different applications,and put forward a framework of digital seal for the public documents based on PKI/CA.The whole system uses the digital seal,which is signed and issued by CA,to aim at the verification and authentication of the document.Some key technologies about digital seal are analyzed, and some main flow charts about the implementation of the digital seal are proposed. The deployments of the system are success,which embodies the rationality of the design and the convenience of using the system.The framework of the digital seal has some references for other ones.Managements of the digital seal such as the application,the loss report and so on are the important component of digital seal system.The different applications of the digital seal have the different characteristic.Based on the analyzing of management features of the digital seal on campus,a verification method using the time-stamp service is put forward.We focus on the variety types of managements of the digital seal,such as the application,the loss report,the reuseing,the reproduction,and writing off of the digital seal.A method,which using time-stamp to solve the problems of the digital seal verification,is proposed.Finally,the flow charts of verification has also given.