Smart card system and methods for proving dates in digital files

摘要

A smart card system and methods for proving dates of digital data files includes a trusted time source, a first subsystem for saving the file at a moment in time, a second subsystem for retrieving from the trusted time source a date and a time corresponding to the moment in time, a third subsystem for appending the date and the time retrieved from the trusted time source to the saved file, a fourth subsystem for signing the saved file with the date and the time retrieved from the trusted time source appended thereto, a fifth subsystem for hashing the signed file to produce a digest, a sixth subsystem for signing the digest with a key to produce a certificate, a seventh subsystem for appending the certificate to the saved file, and an eighth subsystem for saving the file with the certificate appended thereto. All of the subsystems are preferably sealed together within a smart card.