Sending documents for signature

At our preschool, our parents need to fill and sign many documents.  What is the best way to do this?  I created a fillable .pdf and placed a signature field in the document, but the parent just types in their name - it doesn't seem so secure.  Is there a way to require a certificate? I thought acrobat used to do that

Thanks for your help - just trying to pull us into the 21st century.