Design And Security Study Of Digital Time Stamp Service System

As recent progress of information technology rapidly promoting documentdigitization, the quantity of the electronic documents has increased. It isimportant to store, protect and verify the date and time when electronicdocuments are produced, exchanged and signed. Therefore the security expertskeep close watch on it now.Digital data or documents, unlike tradition documents, are ultimatelyimpossible to differentiate the copy one to the original. Digital Time Stampis such a technique that can guarantee the existence and integrity of one documentat the certain moment. So it can verify the earlier one of two disputableelectronic documents. It is meaningful to those who are sensitive to time,including technical patents, secret intelligences and online trades. Besidesthat, Digital Time Stamp improves the security of PKI because of it offeringa long-term validity for digital signature. It is also an important componentof PKI and the un-repudiation service.In this paper, several kinds of schemes has been studied and analyzed.Considering the advantages of PKI that can secure authenticity of TSA's identityand the condition that we can take in technique supporting in time service fromNational Time Service Center (NTSC) that is the national time authority in China,a time stamp service system is designed. The developing platform is made of JDK5.0,Tomcat5 and Mysql4.1. And the system is based on Browser/Server structure. Inthis way, this system can fulfills the demand of client. User can get Time Stampby ticket-booking and public directory service through a mix-net. Finally a realimplementation based on RFC3161 is given on windows system by Java. This designis simple and flexible, it supports many kinds of CryptographicHash algorithmwhich can be alternated. And the key length of RSA is more than 1024 bit.