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Wireless Registers May Expose Your Credit Card

flynt writes: "Found this article about people sitting in Best Buy parking lots with wireless sniffers and intercepting credit card numbers that the wireless cash registers inside the store are beaming about. Gives more credence to the idea of one time use credit card numbers. Now you don't even have to be online to have your number stolen."

22 of 229 comments (clear)

  1. Credit cards *are* insecure by burts_here · · Score: 3, Insightful

    the whole concept of having a card with a number on which you can tell people down the phone, send down the internet, give to people in shops/restauratns is very very insecure, I've ordered stuff on my mums card before, do they care that i'm not my mum, do they shit. If people have to resort to wireless scanners to get card numbers they are throwing way to much money at the exercies, you can get card details much esier from bins, old till rolls etc...
    i have developed a foolproof method of fooling them though, dont have a credit card, ok so they wont actully give me one yet but hey...

    --
    Burt "Out of my mind back in 5 minutes"
  2. Re:encryption by GrenDel+Fuego · · Score: 4, Informative

    Yeah, wireless encryption sucks....

    However, you can add encryption to the tcp/ip running over the wireless. With something like Cash Registers, you can be sure that they're all running the exact same software.

    Enabling IPSec, or something similiar shouldn't be too difficult. it's not like you need to make sure it's compatable with all the different OSes.

  3. security by jaavaaguru · · Score: 5, Insightful

    Lock down all ports on the server except SSH, and force the cash register client machines to tunnel through SSH for everything. I use it at home, work and university. It's better to be over security-conscious than being to relaxed about it.

    However, that's just covering up the symptoms of a greater problem. It would be better if credit cards used a public/private key system, where the acocunt number is sent to the central server which responds with a random encryption challenge, then a chip on the card encrypts the string using it's key and replies. That way no useful security information is being pased around for others to intercept and use.

    1. Re:security by omnirealm · · Score: 3, Informative

      I am developing a financial application for use over Bluetooth from a PDA to a cash register, and I can say from first-hand experience that the problem of security over a wireless domain is not trivial. Your solution to channel everything through SSH is not economically feasible when you consider the processor and memory requirements necessary for *every single* vendor system out there to do this. The problem gets worse when you start talking about cell phones and wristwatches transmitting credit card numbers to vendor systems.

      Bluetooth and 802.11b both have link-level encryption built in, but they both need some work before I would trust them with my financial information. For example, brute forcing the Bluetooth's E0 cipher can be reduced from a complexity of 2^128 to 2^100, and generating a database of keys and sample encrypted data can reduce the problem to a complexity of 2 if a match is found while listening to the communications!

      You will have to clarify what you mean by "the account number is sent to the central server." Is it encrypted before it's sent? Against what key? How does your solution deal with non-repudiation (the device is authenticated, but not the user)?

      One idea I came up with while working on this project was to incorporate the one-time use credit card numbers with client-to-vendor system. Before you leave home, your financial institution transmits a set of randomly generated one-time numbers to your PDA, wristwatch, cell phone, whatever, and the client sends a different number from the set each time he wishes to pay for something. That way, it doesn't matter if the number is compromised after the transaction is completed.

      --
      An unjust law is no law at all. - St. Augustine
  4. Original source by Omega+Hacker · · Score: 3, Informative

    You can find what appears to be the original fwd'd (anonymized) copy of the mail from the guy who first checked this out at this location.

    --
    GStreamer - The only way to stream!
  5. Re:unFrickingbelievable by silentbozo · · Score: 4, Funny

    This is WORST Buy we're talking about, remember?

    The same guys who want to foist copy protected CDs as a standard on their customers? The ones who tried to arrest a customer for trying to pick up a video card that he bought on sale online? The ones with the ultra-crappy customer service?

    If you're still shopping at Best Buy, this fiasco with the wireless registers should be enough to make you go somewhere else.

  6. There should be system security inspections. by Innominate+Recreant · · Score: 3, Insightful
    Each time I fly somewhere, I don't inspect the plane before boarding it. When I go to the grocery store, I assume that the government has inspected the facilities that produce the food I buy. The average consumer has neither the time nor the expertise to inspect each plane or food processing plant to decide if it meets a reasonable standard.

    Government inspection doesn't mitigate any responsibility that a food plant or an airline has. It merely provides the consumer with some assurances. And in most cases (not all) it works. Most of us buy food every week, and most of us don't die of food poisoning. Most planes take off and land safely. However, the food producer or the airline company is still responsible for the product.

    As we rely more system security in our daily business transactions, I think that rigid standards of system security should be created and enforced.

    If we start holding irresponsible retailers, like Best Buy in this case, accountable for damages, you'll see consumers *and* retailers lobbying for such an effort.

  7. Why bother? Thieves can just guess. by j09824 · · Score: 4, Insightful
    Credit card thieves can simply brute force the credit card numbers. Some banks helpfully even assign credit card numbers sequentially or predictably, and the credit card number space is too small anyway.

    Social security numbers used as identification, credit card numbers, and a whole host of other "real world" identifiers and systems are simply extremely sloppy security. In the past, that meant that only a few customers got screwed. With modern computer equipment, a lot of people get screwed.

    What is particularly annoying about it is that the companies that put this sloppy security in place never really have given a damn about protecting their customers--as long as the casualties are not too many and don't frighten the masses away, it's acceptable. In most cases, companies that use sloppy identifiers or security end up not even being legally liable for the trouble and expenses they are causing their customers.

  8. Not surprised by dreamchaser · · Score: 3, Funny

    Is anybody actually surprised that nobody at Best Buy knows how to configure an encrypted wireless network?

  9. Trust by infiniti99 · · Score: 5, Insightful

    Someone down the line knows your credit card number. If you hand your card to the person at the register, then you are placing trust in them. If your information is stolen by a 3rd party, then it is because of the incompetence of whoever you placed your trust in.

    According to the article, Best Buy has since stopped using wireless cash registers. Still, I think the problem is not with wireless itself, but the particular implementation Best Buy was using. Couldn't they simply encrypt the data?

    Of course, credit cards are inherently problematic. Although I use credit cards, I think the system is poorly designed. Basically, you say to a guy, "here's a key to my safe, please only take what you need." IMO, it should be the reverse. We should *give* them the money, possibly by authorizing a transaction via your bank (a cell phone would be the best way, so you don't have to trust an in-store terminal) Thus, everyone would be able to give, but not take. As it stands, credit cards have the worst security of anything. It's ironic too, since a lot of us computer enthusiasts will rant all day about how everyone should be using ssh and GPG, yet we give our login and password to the waitress next time we eat.

  10. No credit card fraud before the internet? by p4k · · Score: 5, Insightful
    Now you don't even have to be online to have your number stolen.

    Like you ever did need to be online to get your number stolen - easiest way to steal credit card numbers is to get a job in a retail outlet and record numbers of customers cards.

    This is *the* classic error in security thinking - only consider the hardware, ignore the human factors.

  11. More validation is needed by min0r_threat · · Score: 4, Interesting

    Credit card transactions such as this validate the credit card number against an algorithm, and ensure that number matches the bank who issued the card and the type of card (VISA, Mastercard et. al.)

    Fine, the number may be legitimate, and the card may be legitimate, but is the actual transaction legitimate? In other words, there is no validation that the card being used for the transaction really does belong to the person making the transaction.

    The practice of skimming credit cards and capturing numbers over wireless networks will continue, and credit card fraud will continue because it is easy to commit . . . probably until some form of smart cards encompassing biometrics are in mass use in the marketplace. Incorporate a finger print into a smart card and small recognition scanner at the point of sale. If your fingerprint doesn't match that on the card then the treansaction will be denied. This won't help on-line fraud or fraud perpetrated during transactions when the cardholder isn't present, but it will cut down on innocent people being ripped off.

    So why don't banks incorporate this? It's purely down to cost. They're not interested in consumers being defrauded, what matters to them is the money the banks lose. Fraud is a big problem, but until the levels of fraud amount to more than the cost of issuing and installing smart card or biometric technology, banks aren't going to be interested.

    In the case of validation, European countries with lower levels of credit card fraud are those with higher levels of validation. Many countries in Europe require a matching signature as well as a PIN number. Sure, the PIN number may be picked up over a wireless network, but it goes to show that more stringent validation checks will reduce levels of credit card fraud.

    And as for using encryption - surely that is just common sense?!

    --
    ~~~~~~~~~ "I must create my own system, or be enslav'd by another man's." William Blake, Jerusalem.
    1. Re:More validation is needed by EasyTarget · · Score: 4, Informative

      Sure, the PIN number may be picked up over a wireless network

      Not necesserily.. the PIN is stored on the card itself (one-way encrypted or sumething.. I'm not well-up on crypto stuff). So therefore the whole pin-processing can go on within the POS (Point-Of-Sale) terminal which just needs to return a success or denial message.

      --
      "Oops, I always forget the purpose of competition is to divide people into winners and losers." - Hobbes
    2. Re:More validation is needed by ddstreet · · Score: 3, Interesting
      the PIN is stored on the card itself

      Nope.

      You want to know what is stored on your card? Not much. US cards (foreign - e.g. Japanese - are different) contain 3 tracks (ISO tracks) which contain up to 98 bytes (track 1) + 46 bytes (track 2) + 139 bytes (track 3). Total up to 283 bytes. So that ain't a lot of info.

      Oh, what exactly is stored on the card? Well take a look at this doc in the MSR (Magnetic Stripe Reader) section. Thar ya go.

  12. Truly a Best Buy by phunhippy · · Score: 3, Funny

    Best Buy sends the credit card info cleartext over 802.11....... hmmmm maybe they really truly are best buy then! They went out and found the cheapest Wireless Point of Sale system.. to them it was the BEST BUY :)

  13. Re:steal away. by GutBomb · · Score: 3, Funny

    but it's not really stealing if i ipurchase things with someone else's card because i would not have bought anything if i did not have someone else's credit card number.

    oh wait... I have been reading slashdot for too long!

  14. high tech credit card theft by GutBomb · · Score: 4, Insightful

    with everyone paranoid about credit card theft using high tech means people seem to forget that while most internet transactions are safe, what you really need to worry about are people who actually handle your card.

    The cashier has access to your nubmer. the accountant has access to your number. the manager of the store has access to your nubmer. some stores print the entire number on reciepts so anybody willing to dumpster dive has access to your number. waiters and waitresses who carry your card off to the register in a restaurant has access to your number...

    and now people in the parking lot have access to your number.

  15. Other Fraud mechanism. by EasyTarget · · Score: 4, Interesting

    If the transactions are in plain-text, is there any checksumming etc.. that takes place.

    It occurs to me that what you could do is be able to intercept (or pre-empt) and replace data in valid transactions.

    Then sit in the car-park, and substitute a different card number in to any refund transactions encountered. Create an account specifically for this, and drain it before any fraud is likely to be detected, easy money.

    All of this is assuming that the systems do not use basic checksumming double-verification etc.. but given that they already transmit them wirelessly and unencrypted, what chance is there that they take even basic protections against false data beiong injected into the network.

    --
    "Oops, I always forget the purpose of competition is to divide people into winners and losers." - Hobbes
  16. online credit card theft by hetairoi · · Score: 4, Funny

    "Now you don't even have to be online to have your number stolen."

    right, before the internet, credit card numbers couldn't be stolen. I also understand that before the internet, no music was ever pirated.

    ---

    --
    you're all figments of my deranged imagination
  17. Original message (FYI) by Denium · · Score: 4, Informative
    To: Vuln-Dev
    Subject: Wlan @ bestbuy is cleartext?
    Date: May 1 2002 3:57PM
    Author: Blue Boar

    I was asked to anonymously proxy this question to the list. Here ya go.

    BB

    This past week I went to bestbuy to purchase a D-link wlan card... egar to get my laptop up and running while in the car I put my card in and installed the driver. I noticed the traffic light was lit up as if I had a connection. Out of curriosity I fired up kismet and sure enough there were packets flying through the air right infront of BestBuy. Well I decided to run in an try to make a Credit Card purchase real quick to verify that my info was not going all over the parking lot in the clear. Well after sorting out my logs I noticed what looked to be like SQL queries and table headers in my logs ... things such as CUSTOMER_ROUTEID, BANKNAME, REGISTER_ID and things of that nature... luckily no where in that data did I find my own credit card. Non the less I decided to run to the store next to BestBuy while I left me PC on grabbing packets. Well yesterday I sorted through the data collected and this time I did indeed find a RAW clear text credit card number....not mine ... but definately a credit card number.

    Heres my delima... I checked out a few of the other best buy stores for "beacon packets" and everyone I drove by was sending them out...so I assume all BestBuy's are wlan enabled. What I need to find out is ... are BestBuys's Cash register terminals indeed using wlan and are they indeed sending out MY data in the clear... I am NOT comfortable using my credit card at ANY BestBuy as of right now... due to legality though I don't feel comfortable walking into the store and confronting someone about it.... for all I know it could be standard BestBuy corp. practices to use nonsecure wlan. I figured by starting a thread other people that have attempted this may have more info or some from BestBuy may be reading the list and they may pipe up.

  18. One time credit card numbers? by BCoates · · Score: 3, Funny

    Gives more credence to the idea of one time use credit card numbers

    Sounds like a great idea, one-transaction cards, with a unique number on each of them, all tied to one account.

    But plastic swipe cards are too expensive to use once and throw away--make them out of paper, better for the environment.

    While you're at it, you could eliminate the need for the seperate credit card reciept by putting the amount and signature on the (paper) card, and handing it to the retailer... you could even that funny non-carbon carbon paper if you wanted a reciept for yourself.

    Print them up in a handy-little tear off pack, maybe throw in a balance sheet so you can keep track of your expenses (if you're so inclined).

    If you let little old ladies get ones with puppies or kittens on them, this radical idea of yours might just be a success!

    --
    Benjamin Coates

  19. I'm going to restate this over and over again. by mindstrm · · Score: 3, Informative

    Check your credit card contract.

    Most say you are liable for fraud only if your CARD is stolen, and only for the time between it's theft and when you report it to the company.

    Any other fraudulent use of your credit card number you are simply NOT liable for. Remember, it's not really your number, and the card is not really yours. It's the property of the issuer, it says so on the back. It's a (weak) security token they issue you in order to identify yourself as someone who has a line of credit. If someone uses that, fraudulently, it is a screwup on the part of the merchant, or the bank. You do not pay.

    If your contract says otherwise, or puts any other liability on you (other than normal, responsible behavior of course), shop around and find something better.

    I realize it's a pain if someone has your number, and starts using it. It can be really inconvenient. But my point is.. rather than treating this like property that they have stolen from us, just like stealing our cash, we should be looking to the credit card companies to make sure this does not become our problem... because ultimately, it's theirs.