Research And Implementation Of The Electronical Seal Based On PKI

The electronical seal is the carrier to perform the functionality of the traditional seal in eletronical documents.It implements the documents' authority and make documents not copied.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.Key management and digital signature are the two bases of the electronical seal system based on PKI.With the support of the project ,"The research and development of the new generation B2B e-business platform",from Science Bureau of Zhejiang Province,a prototype electronical seal system is developed on the research of key management and digital signature.This system provides a good base for the next research.This paper pays greate attention on the research and analysis of key problems of electronical seal system.These problems consist of three parts:system integrity, system security and system validity.After studying the causes of these problems,this paper solves the problems with current popular technology so that the theory basis of the seal system is solved.After solving the key problems of the electronical seal system,this paper analyzes the components and implementing mode of the system.The merge of electronical seal management and CA is brought forward.After comparing the two system,this paper analyzes the feasibility and bring forward the modification of CA to implement the merge.Next,the paper study the implementing mode of the electronical seal system,including two modes.After comparing the two modes,the paper analyzes the suitable environment so that a reasonable mode can be chosen.When a user receives the signed document from the signer,he can compute the digest value and compare it with the original value. If they are not the same,the document is modified.This can protect the document from modification and users can not deny the signature.Meanwhile,the electronical seal can achieve its authority and reality by comparing the cotent of the seal and the digital certificate.