We need someone to advice a secure way of communication between mobile app and a .net backend application. Mobile app will make http calls to the server and the connection between the app and the server cannot stay always open. So for every call we need to implement a security token at the end of the link.
What method/mechanism do we need to implement on the app and server ? What if the connection between the two is not secure, lets say calls are made in plan http !?
What security measures shall we implement on the server application to protect it from attacks or overloading ?
Is it better to host it on our own server or use azure, amazon, or some other provider ?