Using Web Services technology for inter-enterprise integration of digital time stamping

This paper describes the results of a research activity conducted cooperatively by an academic and an industrial party. It presents a practical solution for and an experience in the implementation of time stamping services and their exposition to the Internet for inter-enterprise integration. State-of-the-art time stamping algorithms and crucial issues related to their practical implementation are discussed. Focus is on integration problems which arise when a potentially large community of enterprises - which rely on a handful of heterogeneous technologies is willing to access remote third-party time stamping services. We propose a practical architecture which provides time stamping services, both in terms of relative temporal authentication, based on a linear linking scheme, and of absolute temporal authentication, based on publishing mechanisms as well as on a trusted time source. The architecture has been implemented using the emerging Web Services technology. An integration experiment has been conducted to evaluate the effectiveness of the proposed solution.