I am developing native mobile client for store that requires user authentication in order to make purchases available.
I have my web store page, authentication is provided by CMS (OpenCart).
Now I need to implement secure and robust login on mobile devices.
I am using REST API for getting data public data from web site (products, sales ....).
But what is the best choice if I need to provide secure connection between native mobile client and my web server.
I am using "native" to notice that there is no web view or something similar in the app.
There a lot of similar app from popular online stores ( Ali,Ebay, Amazon) all these app use authorization without browser built in mechanisms, I wonder how do they implement this.
What are possible ways to secure user important actions in native client.
Of course I have read a lot of about this, but there no one good solution as well as any article describes available approaches.
Please suggest what is the secure, robust and not very difficult way to do this.
I am grateful for any help in advance.