How to authenticate your server to my server when a user loads your page in PHP?

user signs up for a key and secret from my site, then they can send/receive from my REST server.

Where I need help is when a user interacts with the REST, how can I determine if they are authenticated using THEIR key and secret? Basicly this will be for a social network site app area. I have seen that many social networks have an app area and use REST and OAuth and sometimes OpenSocial but I have looked at those and they are a bit complex for my needs I think. As for authenticating with OAuth, I guess I do not really understand exactly how it works, maybe it is what I am looking for though? I don't need to authenticate the user who views the page that is running the API, I need the owner of the app's server to authenticate to send back and forth with my REST?

Any advice on how to do this the best way? I would like to do it the best method for future growth, so if I could do it like the big boys do (Facebook, myspcae, hi5, bebo) that would be the way to go I think.

when a request is sent it should pass the key in the URL to my开发者_运维问答 server but they should have there Secret somewhere in there script, I am not clear how to make that work with each other?

OAuth is almost certainly the best way to go here. Using OAuth, you can provide authorization to almost any kind of web-based API that you would like (REST is fine, but so is plain ol' XML over HTTP).

There are some Stackoverflow articles on how to get started with OAuth.

I also find Google's implementation worth studying, as it's both well documented, and a very good implementation from which to take inspiration. They also have a very helpful "OAuth Playground" that will walk you through an OAuth request step by step.