What are the legality issues with esignature. Does Jotform provide any secure signatures?

We have teens and youth who are filling out forms. 

Legality and application of electronic signatures or digital signatures depend on the country or state to where you or your client is located. You can check this page for the effect and validity of digital signatures in different countries: https://en.wikipedia.org/wiki/Digital_signatures_and_law 

I believe they are valid as long as the user is well informed about the terms and you both have an agreement. 

Currently, we have 5 signature related widgets.

Smooth Signature widget 

E-Signature widget 

Sigplus widget 

Initials widget 

Adobe DC eSign Services widget 

The most advance and what we recommend is the Adobe DC eSign Services widget. Forms are also SSL enabled, making sure that connection is secure and private when the form is being viewed and submitted.

I hope that helps.