Time-Stamp Authority (TSA)

The purpose of the service is to assign unambiguous time identification to a certain object. The time stamps usually serve as evidence that at a given moment in the past a certain document existed. Time stamps are issued by a time-stamp authority (TSA). Time stamps are signed by the certificate issued to the respective TSAs.

Time stamps can be used by individuals (e.g. in Adobe Acrobat) or servers (e.g. log signatures).

Key benefits

  • CESNET operates NTP servers of own design with a stable time basis. The precision of server clock is in microseconds;
  • Time stamps assign unambiguous time information to a particular object;
  • Independence of the CESNET Association.

Target audience

The service is available to association members and connected participants with no time stamping infrastructure of their own.


The service is available free of any additional charge to the entities connected to the CESNET e-infrastructure.


The interested entity should send a request to the User care department.

Related services

Last change: 5.6.2017