UT Blog

When digitally signing a message, we too often fail to consider the safety of the whole system, and the possibility that somebody else could use our signatures malevolently.

But what about digital time-stamping? The digital nature of our world raises questions as to how one can prove that a document or application was created at a certain time.

To give an example, Margus Niitsoo, a fresh doctorate from the University of Tartu’s Computer Science Institute, talks about the Patent Office. The Patent Office often needs to prove that documents have been received by a certain date and time of day, so that anyone who tries to register the same idea afterwards can be shown to have applied later.

“What if the patent clerk wants to cheat, and obtains the rights to a promising idea by changing the time stamp?” asks Niitsoo.

Margus Niitsoo surrounded by professors: the supervisor Ahto Buldas and the opponent Berry Schoenmakers from the left, the opponent Helger Lipmaa and a colleague Dominique Unruh from the right.

Under the supervision of Ahto Buldas, professor of cryptography, Niitsoo’s doctoral dissertation focused on the safety of a time-stamping solution developed by the Estonian IT company GuardTime.

“I found a better way to measure the safety of time-stamping, so it can be performed faster. In a way, it’s as effective as it can be – there’s no pushing further.” Continue reading →