How To Use Google Authenticator

Ready for the next step to up your Inter­net secu­ri­ty game? Our goal with this step is to keep your pass­word from being a sin­gle point of fail­ure.

Not too long ago, Google launched a free two-fac­tor authen­ti­ca­tion ser­vice, called “2‑Step Ver­i­fi­ca­tion” (2SV). The Google Authen­ti­ca­tor app is one way to use 2SV.


I took a cau­tious approach to imple­ment­ing Google Authen­ti­ca­tor (GA). I was con­cerned about lock­ing myself out of an account, so I invest­ed a lit­tle time up front to study it.

GA is just one option with­in Google’s 2SV pro­gram. You can make a choice of how you want to get the codes (each con­sist­ing of a six dig­it num­ber) when you need them:

  1. Sent to you by text mes­sage (SMS)
  2. By receiv­ing a phone call
  3. Via the Google Authen­ti­ca­tor app
  4. Using a list of pre-print­ed codes you can car­ry in your wal­let

Also, dur­ing sign in, you can tell Google not to ask for a code again on that web brows­er. This will cut down on your work­load and is fine if you don’t share your com­put­er.

I went to the iPhone App Store, searched for “Google Authen­ti­ca­tor” and installed it. There are also Android and Black­Ber­ry ver­sions.

Then, I fol­lowed the instruc­tions to enroll my Gmail account. As a pre­cau­tion to los­ing my phone, I set a back­up phone num­ber (my wife’s) and I also got some pre-print­ed codes that I’ve put in a safe place.

My first big sur­prise came when I tried to check my email from the Gmail app on my iPhone. With­in the app I got prompt­ed for my user ID and pass­word, and then for my 2SV code. Here are some tips:

  1. You can switch over to Google Authen­ti­ca­tor by dou­ble-click­ing on your iPhone but­ton and scrolling to the right.
  2. Or, you can press the but­ton once and then tap on the icon wher­ev­er it is on your iPhone desk­top.
  3. Note that the codes change every 30 sec­onds. The codes them­selves turn red when they are about to change. There is also a small count-down clock on the right-side of the screen (see screen shot below) so you can get an idea of when the codes will change.
  4. Quick­ly mem­o­rize the six-dig­it code, then switch back to the Gmail app, and enter it.


The next day I noticed my Cal­en­dar iPhone app wasn’t updat­ing. I quick­ly real­ized 2SV was stop­ping me, but I didn’t know how to enter a code. Turns out I had to enroll my Mail and Cal­en­dar apps by using an appli­ca­tion-spe­cif­ic pass­word. It’s not very dif­fi­cult so just fol­low the sim­ple instruc­tions.

Are you ready to imple­ment Google Authen­ti­ca­tor? Why not? If you did already, how did it go for you?

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