Efficient Broadcast Time-Stamping

Abstract

) Josh Benaloh Clarkson University Michael de Mare Clarkson University April 21, 1992 Efficient Broadcast Time-Stamping (Extended Abstract) Abstract Even using an authenticated synchronous broadcast model, the task of unforgeably time-stamping digital documents still presents some problems. It is simply not practical to assume that all participants will record and store everyone else's documents so that creation times can be verified. This paper presents a time and space efficient method for accumulation of time-stamped documents. Whenever a question arises, a claimant can convince any "honest" participant of the time that its document was posted. 1 Introduction The problem of unforgeably time-stamping documents has long been believed to be "open and shut". Given any unpredictable stream of data (e.g. sun-spot activity), one can digitally sign a document together with a sufficiently long portion of the stream at the time of signing. If the document is later revealed, it...