I'm looking for a simple document signing system. You can also view Docusign and see what I mean in terms as well.
Say Sue wants to give Bill a notarized document. She would upload the document (say [url removed, login to view]) to a form on your site. She would also have to fill out a form with whatever information you require to verify her identity.
If you are satisfied with her identity information you create a digital signature for contract.doc. This signature is a block of text which you can email to Sue.
Note that this signature block contains NO information about Sue, it only contains information about contract.doc.
Note also that you could delete [url removed, login to view] at this point, it isn't needed to verify the signature.
Now Sue emails [url removed, login to view] and the signature block to Bill.
Bill can upload the file and signature to your site and a script can test them.
The test script will give one of these responses:
1. The [url removed, login to view] file is _identical_ to the file which you signed.
2. The [url removed, login to view] file is _different_ from the file which you signed.
Note that if anybody made any changes to [url removed, login to view] then the signature verification will report it as failing.
This verification could be done with a script and would not require human involvement.