Set signature verification preferences

Before you open signed documents, set your preferences to optimize Reader for validating signatures.

  1. Choose Edit > Preferences (Windows) or Reader > Preferences (Mac OS), 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 enabled by default.
  3. Click Advanced Preferences, and then click the Verification tab.
  4. Choose the following 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 That Certificate Revocation Checking Be Done Whenever Possible During Signature Verification

    Select this option to require certificates to be checked against a list of excluded certificates during validation. If this option isn