Proof of ownership of a document can be just as important as proofs of content, origin and uniqueness. It is most closely related to the latter.
Music and/or Software provide a useful example. Imagine you write a song or program and want to sell a copy. Your copyright is protected already but now you want to pass limited rights to your loyal customer. How?
You create a new copy of the music/program with an embedded digital unique identifier along the lines of a Validation Reference.
You now create a new record (using Codel's Document Protection Software) which states clearly your retained rights and the customer's limited rights. It can include the hash of the music/program, the hash of the modified copy, the hash of the VR and the hash of your copyright claim. It also includes a one time key for use as an anonymous identifier. The record can quite safely even include the name of the customer (this will never be uploaded - but its content will be validated by the hashes of the record)
The relevant hashes of this record are registered. A copy of the music/program, together with the hash-record (including the relevant one time key) are now passed to the customer. They use the one time key to replace it with their own. They now hold incontrovertible proof of the licence agreement between you and them which entitles them to hold a copy of the music or software.
Unfortunately this isn't a solution to the piracy problem. Nothing in the arrangement prevents copies of the music being played without any record of the hash transfer, unless a somewhat oppressive policing regime is instituted to go through people's music collections and prosecute possession without registration. The only deterrent it contains is that, being a modified copy, should it ever be found in possession of a non licence holder, the source of the copy will be traceable.
Alternatively, in time, and with a considerable degree of industry agreement and co-operation, hardware with the ability to go online (which is likely to be most hardware in the medium future) could be made to block the playing of copies whose unique identifier did not match their registration hashes.
Meanwhile, it does offer some potential incentives to registration.
For example, if the music is lost, damaged or stolen, the musician can offer to replace it for free - providing it is a registered copy.
Registered copies could qualify registrants for special offers.
Codel handles ownership by storing the hash value of a unique identifier provided to us by the client registering the ownership. We don't know - and don't need to know - what the unique id is. And nor should anyone else. That is precisely how ownership is protected. Provided the author or owner can keep secret that unique identifier, but can produce it when challenged, to show that its hash value matches the Codel record, then unless the challenger also has the same unique id, the author has effectively proved that they must have been the source of the registered hashes and thus must have created or legitimately obtained the rights to the disputed document.
Note, importantly, that this also means that Codel doesn't need any personal details about authors or owners of documents (or any other data). This is a vital part of our Trust Model. We never store sensitive data.
This does, however, require some degree of care and personal security on the part of authors and owners who wish to protect their interests. Codel cannot offer remote security but we do help by providing Codel Document Protection Software which is designed to manage the registration and validation process. It deals with the "proof of ownership" issue by creating one time keys which are stored on the clients personal computer in a database which contains the other relevant details of the document/s being protected.
The software makes it easy for authors to find the details of their protected documents and, if required, to submit the hashes of their one time keys to prove ownership, or even, to transfer ownership.
