I do not pretend to know everything about restful web service, that is why I am asking.
I have developed some restfull (JAX-RS)resources that is about it
consider this as a brainstorming session and then if I am really interested I will pick up some ideas
At Master's degree level I would be expecting your dissertation to demonstrate some improvement or advancement to a particular field of study. I'm not sure a research study on an existing and well established technology such as REST is going to be enough. I guess you should talk to your supervisor about it though as he or she will be able to give you a definitive answer on that.
Did your University department not provide you a list of projects that you could choose from? I know my CS department did for my Master's degree. Was there nothing on there that took your fancy?
One possible approach would be to search for current uses for REST. Then get a simple RESTful Web service running on your own. Finally, think of a few ways you can either improve on the services you've investigated, or perhaps come up with an idea for a new area for using REST. Or maybe an improvement to the Oracle RS API. Or an extension to servlets to support all HTTP methods. Or [fill in the blank with a cool idea]...
For a master's degree, the innovation does not need to be earth-shattering. Also, some universities allow an alternative to the thesis in the form of a research project, so if you can't figure out an innovation, maybe you can figure out, say, a best practices commonality among implementations. Be creative. Give your advisor a few options, and maybe he/she will approve one of them.
Give a man a fish, he'll eat for one day. Teach a man to fish, he'll drink all your beer.
Cheers, Jeff (SCJP 1.4 all those years ago...)