Adobe Acrobat 9 PRO Extended - Manual (Page 276)

270 USING ACROBAT 9 PRO EXTENDED
Digital signatures
Last updated 9/30/2011
2 Choose Add Verification Information.
The command is unavailable if the signature is invalid, or signed with a self-signed certificate.
Set signature verification preferences
1 Open the Preferences dialog box, and select Security on the left.
2 To automatically validate all signatures in a PDF when you open the document, select Verify Signatures When The
Document Is Opened. This option is selected by default.
3 Click Advanced Preferences, and then click the Verification tab.
4 Select verification options.
5 (Windows only) Click the Windows Integration tab, and specify whether you can import identities from the
Windows Certificates feature into the list of trusted identities. In addition, specify whether to trust all root
certificates in the Windows Certificates feature when validating signatures and when validating certified
documents. Selecting these options can compromise security.
Note: It is not recommended to trust all root certificates in the Windows Certificate feature. Many certificates that are
distributed with Windows are designed for purposes other than establishing trusted identities.
Verification options
When Verifying These options specify methods that determine which plug-in to choose when verifying a signature.
The appropriate plug-in is often selected automatically. Contact your system administrator about specific plug-in
requirements for validating signatures.
Require Certificate Revocation Checking To Succeed Whenever Possible During Signature Verification Checks
certificates against a list of excluded certificates during validation. This option is selected by default. If you deselect this
option, the revocation status for approval signatures is ignored. The revocation status is always checked for certifying
signatures.
Verify Signatures Using Select an option to specify how to check the digital signature for validity. You can check by
the current time, by the time set by a timestamp server when the signature was signed (the default), or by the time the
signature was created.
Use Expired Timestamps The validation process uses the secure time provided by the timestamp or embedded in the
signature, even if the signature’s certificate has expired. This option is selected by default. Deselecting this option
allows discarding of expired timestamps.
Signatures panel overview
The Signatures panel displays information about each signature in the current document and the change history of the
document since the first signature. Each signature has an icon identifying its verification status. Verification details are
listed beneath each signature and can be viewed by expanding the signature. The Signatures panel also provides
information about the time the document was signed, and trust and signer details.