The following features needs to be implemented before okular supports digital signature verification:
 1.Signature form field.
- Related Revisions: D11723
 2.Revision manager to keep track of previously signed versions of the document.
 3.Signature summary dialog to inform user about document’s integrity and authenticity.
 4.A popup to display the signature validation summary.
 5.Certificate properties dialog to display information such as signer’s name, issuer’s name, signing time, algorithm used, intended usage of the certificate, etc.
 6.Signature widget.
 7.Signature panel to provide one point access to signature properties and previously signed versions of a document.
 8.Menu actions.