To set preferences for Digital Signatures, choose File > Options > Signatures.
Creation & Appearance
Click More for the following settings:
Compatible with Adobe Acrobat
Select this so that Adobe Acrobat will be able to verify digital signatures from your PDF documents. If you deselect it, only other copies of Power PDF can verify your signatures.
Defaults
Choose a default signing method and format.
When Signing
Choose which items you want to be visible or required in your signatures. You can require a signing reason and/or time stamping information, include contact information and revocation status.
Appearance
Lets you create, duplicate and delete signatures and edit their content in the Configure Signature Appearance dialog box.
Verification
Click More to choose how signatures in documents you receive are to be verified. Select check boxes to have signatures verified when documents are opened (by default on) or flag untrusted signatures (by default off).
Specify a default verification method and choose which method should be used to verify signatures; this default method or the method specified in the document. In the latter case choose how to proceed if no method is specified—be prompted or use the default.
Choose which time to use for verification: current time, signature creation time, or a time embedded in the signature (for example a time stamp).
Specify in the Verification Information section, what to do with the verification information when saving a signed PDF. Select one of the following options:
Ask When Adding: When such information is added to a document, Power PDF starts a dialog box to ask.
Always: Verification information is saved with the signed PDF document automatically.
Never: Verification information will not be saved.
Specify whether you want trusted identities stored in the Windows Certificate Store to be accepted when validating signatures and certified documents. If you want to decide on a case-by-case basis, you should not enable these options.
Identities
Click More to manage your digital identities in the Digital ID List dialog box. Use the left panel to see all identities or only those from the Windows system.
Document Time Stamping
Click More and choose Time Stamp Servers in the left panel to configure (add, remove, modify) settings for time stamp servers. Set a default server so that time stamps are added to all documents you sign.
See also: About Securing PDF and Sign/Certify panel.