UNIVERSITY OF COLOGNE

While your personal certifacte suffices to show that you created a signed document it is not able to provide any security against tampering at a later date. You can mitigate this by using a Timestamp-Service to provide your signed document with a timestamp. Therefore one can easily assess whether or not a singed document was unknowingly changed afterwards by comparing the timestamp from the signature to the last modified date of the document.

The DFN-Verein provides its own Timestamp-Service. This ensures that no corrupted time can be used improperly.

To make it more comfortable for you to import the timestamp server, you will find a .fdf-file here:

1. Download the .fdf-file (TimestampServer-UoC.fdf)

2. Execute it with Adobe Reader or Adobe Acrobat.

3. Click on 'Import' in the window that opens [Picture 1].

4. Confirm the security message with 'Yes' to use the time stamp server by default [Picture 2].

5. Confirm the appearing message with 'OK' [Picture 3].

4. Set up the personal certificate