A time stamp ensures the allocation of the current time to existing data, information, files or events. It is therefore attached to documents or data with respect to which we want have the possibility of verifying in the future that they existed in this form prior to the time indicated in the time stamp.

The service is provided under a contract. Time stamps are issued by a time stamp authority upon an electronic application in a normalized form, which includes a fingerprint of the data for which the qualified time stamp is to be issued. If the application contains all the required information, the time authority will create a response containing the data fingerprint that was included in the relevant application, accompanied by the current time and other necessary specifications, and send it to the applicant.

An issued electronic time stamp includes at least:

  • The unique number of the electronic time stamp
  • Specification of rules under which the electronic time stamp has been issued
  • The time, whose deviation will not exceed 1 second from UTC  (+/- 500 ms)
  • Data in an electronic form – fingerprint (hash) of the data, for which the time stamp has been issued
  • The electronic sign of the service which has issued the time stamp

The service is available 24/7/365; it is therefore a non-stop service. I.CA guarantees high reliability of the service, which is documented by individual applications and also notable customers who have associated the operation of their solutions with the purchase of I.CA qualified time stamps.

Under contractual terms and conditions, I.CA guarantees 99% availability, and the factual availability is almost 100%. In 2013, for example, the overall availability was 99.99%. 

Client – Time stamp Authority Communication

The communication between the client applying for a time stamp and the time authority server is done on-line in a request response regime. For communication with the time stamp authority and work with time stamps, I.CA provides its clients for free with:

  • I.CA QTSA application for the Windows environment, which allows acquisition of a time stamp for a particular document or file. It is suitable for the issuance of a time stamp on an individual basis by an end user. It stores the time stamp in the TST (TimeStampToken) or TSR (TimeStampResponse) format.
  • Line client sets – C platform, Java.
  • DLL library – libraries supplied by I.CA are available for the Windows and Unix environment. They are designed for integration in own systems for the automated use of the service of a time authority.
  • Library for Linux is delivered as a native library in 32-bit and 64-bit version, including the needed files and other supporting libraries, the library is delivered test applications.

Another method is own specification of a data structure, and this use requires knowledge of the standard applicable to time stamps, which, among other things, defines the data structure of a time stamp (RFC 3161).

Service Authentication

The system of the time authority supports the following methods of authentication:

  • by an I.CA commercial certificate – this commercial certificate is issued to the client for free after the signing of the contract at the registered office of the company. Customers of the time authority of may this certificate also be used for access to client services that are offered with service time authority. Create an request for the certificate,
    Generate Request
  • by a static IP address (it is always the IP address on the end computer the applicant about timestamp),
  • by username and password,

These authentication devices are always in the Annex the Agreement on the service I.CA.

Registration authorities



8/28/2019 Swedish partnership
More here
7/16/2019 I.CA starts issuing certificates using elliptic curve cryptography (ECC)
More here
3/27/2019 I.CA became a member of the OBE QTSP Working Group
More here