Signing forms is one of the most common business requirements. With Live Forms, you can sign in one of two ways.
Wet Signature Control
Drag and drop a Signature control anywhere in the form. You can name it, change the label, set its width as desired. When using the form, the user simply clicks in the control with his/her mouse on a desktop computer or touches the control with his/her finger on a touch screen device. A box pops up asking the user to sign. If the form/flow property Accessible is enabled the user can type a Name at bottom left. The signature is displayed on the form and is also displayed if the form is printed.
A digital signature can be applied to any Section in the form. Drag and drop a Section into your form and add some controls into it. Then, select the Section by clicking on the header and in the Properties panel, click on the Security Tab. In the Signature property, select Text/Signature image. See that a "Sign this section" button appears at the bottom of the Section. If you check the "Must Sign" property, then the form cannot be submitted unless the Section is signed. Otherwise, a signature is optional. Similarly, drag and drop another Section into your form, add some controls and enable a digital signature as above. This time, in the Signature property, select Wet Signature and check the Must Sign property.
Save your form and Test it. Try clicking the "Sign this section" button in both Sections and see how it gets signed but in different ways. In both cases, you must be authenticated to Live Forms otherwise an authentication dialog is displayed. Notice also that when the Section is signed, it is locked and can no longer be edited. If you wish to change any value, you must click "Edit this section", change the value and sign it again. The act of signing generates a digital signature based on the data entered into the controls. This digital signature can be used to validate at a later time (e.g. in a workflow or when viewing the submitted form at a later date) that the data in the controls has not been tampered with. If the data changes, the signature will be invalid and a red bar will appear at the bottom indicating data tampering.
As before, the signature is displayed on the form and will also be displayed when the form is printed.
You can learn more in the Electronic Signatures chapter of the documentation.