Apps Protecting content on mobile device

[foobin]

Hello,

I am in the process of researching how to build an app for my product.

Is there a way where content download from web via the app can be either protected, encrypted or secure from external parties finding a way to copy it off the mobile device?

Basically i want to know how can i protect my downloaded files once it has been downloaded to the device, via the app, for using in offline mode.

Thanks.