I have a service with a Django-based RESTful API that is designed for iOS devices to access. I'd like to store some user data on the server -- non-sensitive things like favorites for example. I don't want to make a new user create an account, but I would like for the data to not be publicly available. The service also uses Apple's Push Notification Service (APNS). All traffic to and from the service uses TLS/SSL.
I am considering using a CFUUID generated by the device on first launch as a username and the token provided by APNS as a password. I would create a user account after I successfully register the device with APNS and update the password if the APNS token changes.
Is this a bad idea? Is there a better approach?