title: Best way to secure Private REST API without user authentication for mobile app
body: <p>I am making some Restful APIs for my mobile application.</p>
  
  <p>The communication between APP and webserver has to be made in REST. These apis should be private , and only my app should able to call them for successful results. </p>
  
  <p>The tough part is, there is no user id and password required in my app so i do not know how could i restrict rest API with the mobile app without basic user authentication. </p>
  
  <p>One solution i thought was to embed some kind of hardcode string so when mobile app will use the restful url they will pass that in encryption format over ssl. But i know this seems like very bad solution..</p>
  
  <p>kindly suggest what should be the best solution under such situation.</p>