Adobe Form- 2 signatures with changes

Hello. I am creating an adobe form that has 2 different sections on the one form. The first section, one individual completes the fillable areas and does an adobe certificate based signature. They then send the signed form to another party. This party adds information in fillable areas to their section of the form and signs with a certificate based signature. How do I create the form so there are not issues with effecting the validity of the first signature because the form had things added to it after it was signed?