/*
  * (non-Javadoc)
  *
  * @see de.intarsys.pdf.encryption.ISecurityHandler#authenticate()
  */
 public final void authenticate() throws COSSecurityException {
   // reset permissions
   setActiveAccessPermissions(AccessPermissionsNone.get());
   if (authenticationHandler == null) {
     authenticationHandler = AuthenticationHandlerFactory.get().createAuthenticationHandler(this);
   }
   authenticationHandler.authenticate(this);
 }
 @Override
 public void initialize(STDocument doc) {
   super.initialize(doc);
   setActiveAccessPermissions(AccessPermissionsNone.get());
 }