body: I'm not a law student, but I'm very interested in the topic and learning in general. 
  
  
  I got curious about contracts and signatures recently, so I wondered if there have been cases where contracts have been voided because of invalid signatures. 
  
  
  What constitutes a person's official signature, and what are the criteria (if any) for the validation of one's signature?
  
  
  
title: How to prove the genuinity/nongenuinity of a signature?