基于PKI的信任服务体系-通信与信息系统专业论文.docxVIP

海交通人学硕卜学位论文PK 海交通人学硕卜学位论文 PK I——Based Trust Se rv ce System ABSTRACT Taking advantage of the openness and universal interconnection of Internet，E—conlmerce and E—governmenl blooms so dramatically However，ntlmerous problems arise with the growth of Internet and E-commerce．Among them，security issue is one of the most critical ones， which has many closely related，but essentially different meanings，like data integrity，data confidentiality，non—repudiation etc，The most critical concept among them is tractability，which plays the core role in various security services．Thus，Trust Service System possesses great significance in Internet security and has wide applications In general，the key to alleviate security problems is crypto technique， including conventional symmetric cryptography and recently asymmetric cryptography．Public Key Infrastructure(PKI)is the facility providing crypto services，such as key management，distribution，and most importantly certificate management，which includes issuing public key certificate，revoking certificate，helping with certificate verification etc In another word，the main task of PKI is authentication．Therefore，PKI is the groundwork to build a trust service ffamewoN because it provides the atomic security semantics．As a typical instance of Trust Service System，CSCSM(Content SecuriOe Classification Management System) 卜海交通火学埘lj学位论文helps 卜海交通火学埘lj学位论文 helps intemet users retrieve wanted information and reject those unwanted，by providing 1)information origin authorization；2) information integrity protection；3)information non—repudiation；4) nformation access control；and as a bonus，5)time staroping service In son-le applications，wlaich require higher security，especially in information aCCeSS，PKI is not capable to meet such requirement Privilege Management Infrastructure is a counterpart of PKI．Instead of manage public key certificate，it complements PKI by managing attribute certificate and p J‘oviding authorization functionality．Under the help of PM