Digital timestamps mark a PDF signature with the time and date as proof of integrity. A timestamp shows that the contents of the document existed at a point in time, and are unchanged.
For added security, digital signatures can include a timestamp from an independent, trusted authority. Nitro Pro is able to utilize a timestamp server to help ensure that the timestamp is precise and secure, since the system clock could be modified by a user.
1. In the File menu, select Preferences, expand Digital Signature, and select Time Stamp Servers
2. If the list of Available servers is empty, or you want to add another timestamp server:
3. To manage existing settings for a timestamp server, tick the Acquire timestamp from attestable server checkbox, select a timestamp server from the list of Available servers, and then do any of the following:
4. Click OK
TIP: If your default timestamp server is unavailable, Nitro Pro uses the first available timestamp server on your list. You are advised to list them in order of preference.
When you look at the properties of a digital signature, time validity is shown as one of the following:
For more information, see Digital signatures.