Digital Time-Stamping Service Base On Service-Oriented Architecture

Web-based business activities and handling official business by computer is so frequently today in e-commerce and e-government, with producing a large number of electronic documents. To store, protect and verify the data of the date and time which takes place when electronic documents are produced, exchanged and signed becomes so important that security experts pay close attention to it in recent years. Digital time-stamping is a set of techniques enabling us to ascertain whether an electronic document was created or signed at a certain time. It can be used for verifying which of two disputable electronic documents is created earlier. It is very important to those which are sensitive to time include technical patents, secret intelligences and online trades. Besides, digital time-stamping improves security of PKI because of offering a long term of validity for digital signature. Digital time-stamping is important component of PKI and support un-repudiation. As to existing linking schemes for time-stamping, there are still some drawbacks unresolved. They are either costly in time-stamping verification or complication with understanding data structure and algorithm. The paper presents a new round-based linking time-stamping scheme. It creates large rounds with smaller rounds as well as takes advantage of linear linking scheme which is simple and supports relative temporal authentication. It needs a small fraction of the whole timestamp chain between two timestamps as key point to build a verifying chain when verification processes. In this way, it has reduced time complexity and computed with great efficiency in verification of timestamp chains; On the other hand, because the efficiency of verification improves greatly, a lot of trust timestamp available can be used for repeat verifications so as to ensure that the evidence verified has convincingness even more. In addition, the design of time-stamping system is realized in the form of web services in the article. The system is divided into four web services including ticket-booking, time-stamping, time source synchronization and public directory under the service-oriented architecture and operated through association among those web services. Meanwhile the system provides anonymous time-stamping service and can be easily integrated into other systems. At last, the paper presents a definition of process with BPEL4WS for business process from every web service being execution of automation.