Witness

"Witness" will be a web app which provides proof that person A has agreed to legal document X.

There are loads of applications for this:

Proof that a Mozilla contributor has agreed to our Committer’s Agreement
Proof that someone has agreed to the IPR policy necessary for contributing to a standards body mailing list
Proof that someone has agreed to a trademark licence

These things can be done without an app, but it’s dull and tedious for the person doing the paperwork. Much better to get a computer to do it.

Persona login (we need strong identity verification, and this saves us having to do the email confirmation dance ourselves)
Admin interface (specially-blessed accounts) where someone can submit a document. Define:
- Document title
- Document text (HTML? Some other structured text format?)
- Document version number (string)
- Text for 'Yes' button and 'No' button (is this dangerous, if they "switch" the meanings? Or does logging of actions avoid that problem?)
Also ability to upload updated document as long as version number is also changed to new unique value for that document
Page for all previous versions links to latest (most recently uploaded) version
Users can see all documents on system, or get a URL which takes them straight to the display of a particular document
User clicks "I Agree" or "I Don't Agree"
Action is recorded in database, with:
- Identity of user (email address and real name, if available)
- Decision (Yes or No)
- Text on clicked button
- Date and time of agreement
- Source IP address
- Persona assertion
- Hash of text involved
- Version number of text involved
User receives email telling them what they've done
Ability for uploader to get list of email addresses of all signers
Ability for user to change mind later - go back and click a different button. App records history of agreement/disagreement, not just last decision
Admin needs to be able to retire a document - remove it from the public list and "close" signatures on it

Logging of all changes and not-already-logged actions
Ability for user to send URL which gives proof they've signed to a 3rd party (URL contains random value to avoid identity leak; URL given to user after signing)
Hash of text presented to user is calculated client-side and submitted, but checked against server-side value to make sure no discrepancy
App stores result of sending all action data listed above (including confirmed text hash) to a 3rd party timestamping service, for better non-repudiation
Ability for uploader to search list of signers
Ability for admin to email all signers to inform them that a document has been updated and they should come back and re-sign
Notifications to document uploader when someone signs it
Possibility of list of signers being public