If you were as rabidly anticipating the new version of the iPhone, iPod touch, and iPad software release, iOS4, as I was, you’ve probably already upgraded your device. But, what do you do if the upgrade sours? Your iPhone crashes and is not functional? Or just as bad, you have a software fluke and your authenticator serial changes, effectively locking you out of your account? If you follow some simple security measures, you can avoid these problems entirely.

The first thing you should do (and have already done) is write down your authenticator serial number. This is a number unique to your device that’s used to generate the codes. If you have the serial number, you can call Blizzard and have the authenticator removed at any time . Store it in a safe place. I put mine in a Google Document, where I will probably never erase it and I can always access it. This way, if my phone gets lost or destroyed, or if I accidentally uninstall the authenticator, I will be able to save it at any time.

To find your serial number, follow these steps.

Open the app
Go back to the menu
Touch “Setup”. Now write this number down.

However, it’s still a pain to remove the authenticator with the serial. You still have to get on the phone with Blizzard. If you are doing a software or firmware upgrade, it might be best to play it safe and temporarily remove your authenticator. Here’s how:

Log onto Battle.net. Go to “Change Security Options”
Press Battle.net Authenticator
Enter in two consecutive keys

Don’t forget to re-add it when you are done and make sure you remember to write down your serial number in case it changed.

Anyone have any authenticator horror stories?