Credit Card Activation a security risk

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You may have received a credit card with a sticker on it asking you to activate your card by calling a special number for your home phone.

The credit card verification system uses caller ID or ANI to check the number you’re calling from and checks to see if that’s the home number they have on record for you. The idea is that only the legitimate cardholder can call from their home phone. I mean you have to be inside my house to call from my home number, right?

I use a VoIP system as my home phone. Any calls I make are transmitted over the internet before they make it onto the regular telephone system. I’ve got a regular phone number—in fact it’s the same number I’ve had for five years, even before I used VoIP. My phone number shows up in caller ID, just like a "regular" phone. The difference is, for normal landlines, the caller ID information is set at the local phone office. For my VoIP system, the number is set in my phone system—a little box that sits on a shelf in my house.

That means I could change my caller ID to show any number I wanted. I can show mine. I could show yours. I could show up as anybody.

A bad guy that intercepts a new credit card only needs to know your home phone number to use a similar system. And it’s not hard to get someone’s home phone number.

So why are credit card companies using an easily-discovered and easily-spoofed token for authentication?

October 10, 2006 2:18 PM

Maybe because in the history of credit cards, voip is very new technology. They've been around in commercial/personal use for something like 50+years now, and voip? A few years, tops. Mind you, activating online requires you to enter, what, your phone number? postcode? digits on the card/paper? All this is verifiable through taking your maill (when they take your card in the first place). Social security number? Obtainable. Mothers maiden name? Same. Frequent fliers number? Easy. Makes you wonder what IS a safe way to verify personal information/identity. At least you're covered on a credit card for misuse :)

October 11, 2006 2:49 AM

It is a bit stupid of them to not test that is secure before using it and if they had this flaw should have been noticed and sorted lets hope they stop this form of activation soon.

Tama D.
October 12, 2006 4:46 PM

I don't think it is designed to deter the most sophisticated of criminals and hackers, but I think it is rather cost efficient and effective deterrent from petty thieves and what nots from snatching a new card in the mail and activating it.

October 14, 2006 8:16 AM

Telephone-based card activation has been around for a lot longer than VoIP systems. Credit card systems take a long time to change. And the coffin's nail: There are much easier ways to steal your credit card...

May 20, 2010 12:36 AM

So are you guys saying anyone that got a card in the mail can just call the activation line show the card holders phone number and thats it, and its activated???

Adam Kalsey
May 20, 2010 9:50 AM

Yes, it's trivial to make a phone call as you or any other number. I can do it with two lines of code.

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