Hi, I'm creating an iPhone project, and will be communicating with a server via REST. I will be sending push notifications, initiated from another service. I would like to authenticate all communication from the iPhone to my server (e.g., synchronising notifications with the server as the push request is not guaranteed to go through) 2 legged Oauth seems to be the ideal solution, however there is not a lot of information regarding it, especially as most of the libraries seem to be oriented towards consumers and not providers. What library should I use? Is Oauth overkill? If so what do you recommend? I'm looking for the simplest possible solution at the moment; If it is going to take me more than a week to implement Oauth, it's simply not worth it. Thanks