How to Time-Stamp a Digital Document

The prospect of a world in which all text, audio, picture, and video documents are in digital form on easily modi able media raises the issue of how to certify when a document was created or last changed. The problem is to time-stamp the data, not the medium. We propose computationally practical procedures for digital time-stamping of such documents so that it is infeasible for a user either to back-date or to forward-date his document, even with the collusion of a time-stamping service. Our procedures maintain complete privacy of the documents themselves, and require no record-keeping by the time-stamping service.

• Type: Conference
• Year: 1990
• Where: CRYPTO
• Authors: Stuart Haber, W. Scott Stornetta
• Keywords: CRYPTO 1990, Cryptology, Digital Time-stamping, Modi Able Media, Time-stamping Service