Q:

Key authentication

I bought PC World magazine which came with an installation disk for Ubuntu 16.04. 
When I wanted to install applications from the store, there appeared a prompt for key authentication. What should I do?

A:

Authenticate in the Software Center with the same user password that you use to login to Ubuntu. Or just press Enter if you haven't set a user password yet, but if you haven't got a user password you should set a strong user password to keep your operating system secure.

