Adobe ACROBAT READER 7.0 Manual page 149

Setting Digital Signature preferences
You can use the Security panel of the Preferences dialog box to change the appearance of
your signature, specify a default security method, change validation settings, and specify
other advanced preferences. (See also
To set advanced digital signature preferences:
1. In the Preferences dialog box, select Security on the left, and then click Advanced
Preferences.
2. To require certificates to be checked against a list of excluded certificates during
validation, select Require That Certificate Revocation Checking Be Done Whenever
Possible When Verifying Signatures. The Online Certificate Status Protocol (OCSP) and
the Certificate Revocation List (CRL) are common schemes that maintain security of a
network server, containing lists of revoked but unexpired certificates. If this option is not
selected, the revocation status for nonauthor signatures is ignored.
3. Under Verification Time, select an option to determine whether the time that appears in
the digital signature reflects the time the signature was validated (Current Time), the time
set by the default Time Stamp Server specified in the Security Settings, or the time the
signature was created.
4. Click the Windows Integration tab, and do the following:
Specify whether you can import identities from the Windows Certificates feature into the
list of trusted identities. (See
Specify whether to trust all root certificates in the Windows Certificates feature when
validating signatures. Be aware that selecting this option might compromise security.
Changing signature
Building a list of trusted
appearance.)
identities.)