Securing info between app and back end

Hi,

Looking at developing an app. Wanted to ask what is the recommended way to secure a unique identifier given to the website owner. So if I want to track his/her activity via some unique token I give him/her, how can I prevent a hijack on the visitor side?

Thanks,

Charlie

Could you detail a bit for the situation at hand? Your answer is as generic as they come and doesn’t seem applicable.