Validate a time stamp certificate

If a signature displays the date and time, that time is the local time on the signer’s computer. However, a second date and time may appear in the Signature Properties dialog box, indicating that the signer uses a time stamp server. To validate a signature contained a time stamp, you must obtain the certificate for the time stamp server and add it to your list of trusted identities. Otherwise, the time stamp appears in the Signatures panel as unverified, and you must validate the time stamp manually.

  1. Click the Signatures button  in the navigation pane, select the signature, and choose Validate Signature from the Options menu.
  2. Click the Signature Properties button in the Signature Validation Status dialog box.
  3. In the Signature Properties dialog box, click the Date/Time tab to view the time stamp authority, and then click the Show Certificate button. (This button appears on the Date/Time tab only if the signer used a time stamp server.)
  4. In the Certificate Viewer, click the Trust tab to determine if the time stamp certificate is trusted. If it isn’t trusted, click Add To Trusted Identities. If a certificate for the time stamp server isn’t listed, request one from the signer.