If you include a Formotus Ink Control to capture signatures, you may want to use the technique shown in this signature lock demo form to prevent any alteration of the signature or other data after the form has been signed.
The idea is to use two different InfoPath views: one view contains all the input controls, while the other "locked" view allows no data input but includes the submit button. An Accept button below the signature control switches to the second view, and there is no switching back.
How to display the signature without buttons
The input view uses the whole FormotusInkControl template part section. The locked view uses only the Signature field from the control.
From the input view, copy just the signature image itself and paste it in the locked view. Alternatively, drag the Signature field under the Ink group from the Fields pane to the layout pane.