F5 Authentication Method for Mobile Devices

Hello,

I am building a hybrid mobile app and am having difficulty understanding how to implement user authentication.

This is a data-entry app where I am using a RESTful service to post JSON data.

My idea has been to have the user authenticate through a login screen (username/pass) which hits AD. On a successful login, I would like to receive a token which will be stored and sent in each POST attempt. The service then allows data to be submitted if the token is valid. How can I create this service?

I am open to other authentication methods, this is just what I have had in mind. I am having difficulty understanding how to implement any sort of mobile authentication in general.

Thanks,

Andy