iOS 7 Email Security Address

My iPhone finally installed the update and is back up and working. My iPad says it's downloaded but the verification and installation are failing. I have a question though, once I went through the set up screens on the phone I was asked to add an email address for security purposes for later identification. It would not allow me to use my Apple ID/iCloud addresses - I have 2, one which is specific to me, one which is shared with my wife. I was forced to use one that my ISP provides but didn't really want to because I could change ISPs in the future. Can you enter a fake/made up email address to use for this?

When I'm able to I will be updating my iPad and I'm not sure what address I will use for that, don't know if it will let me use the same one I used for the phone. Any ideas?