An electronic time stamp is data in electronic form which binds other electronic data to a particular time establishing evidence that these data existed at that time. An electronic time tamp is a signature so it prevents time-stamped data from modification.
Electronic timestamps are designed to capture the state or event of an electronic object and provide legally binding evidence. Today's practice is dominated by the use of qualified electronic time stamps to prove the validity of qualified electronic signatures and seals, and at the same time the validity of the corresponding electronic documents.