Time Stamps
From a technical standpoint, a time stamp is a signature of a time stamp service that contains a time reference in a very secure format. This signature freezes the content of a document (or any other electronic data) - the time reference makes it possible to prove the moment of "freezing".
It is, of course, most decisive how safe or reliable the time reference in the particular time stamp is. The legally valid time in the sense of the signature law is defined exclusively by the German time law and the DCF radio signal emitted from the Physikalisch-Technischen Bundesanstalt in Braunschweig (Germany).
To judge the reliability of a time reference, it is now decisive whether an error or manipulation can be excluded between receipt of the DCF time signal and insertion of the time in a time stamp. For a few applications, a deviation or error source can sometimes be tolerated - the legislation has drawn very narrow margins for this in connection with (legally) secure time stamps in accordance with signature laws. Thus, for a legally secure time stamp, an independent test of the hardware, software and other technologies used is a mandatory stipulation, before utilization.
The creation of legally secure time stamps, known as "qualified time stamps", is reserved solely for registered and accredited providers. In this case, not only the prior inspection of the hardware and software used, but also the secure field environment (Trust Center) is subject to supervision by the Federal Network Agency (formerly regulatory authorities for telecommunication and post).
A qualified time stamp can therefore only be created within an accredited Trust Center. In practice, a digital fingerprint (hash-value) of the document is created locally and sent to the Trust Center. The Trust Center creates the time stamp and sends this back to the source.
Qualified time stamps from accredited providers can be checked for validity over a time period of at least 30 years. This allows, for example, a document's unaltered state and time of creation to be proven in court in accordance with the signature law for a period of over 30 years.
For digital cerificates from governmentally accredited certificate providers only, the Federal Network Agency guarantees that any certificate may be verified for a period of 30 years after its expiration date.
In addition, the qualified time stamps from AuthentiDate are insured against financial loss for 2.5 million euro per time stamp in accordance with the signature law. Thus, the user is optimally safeguarded in terms of reliability and security when changing over to electronic media from paper based processes of major importance.
