Slashdot Mirror
Cracking Atlanta Subway's Poorly-Encrypted RFID Smart Cards Is a Breeze
McGruber writes "Seven metro Atlanta residents are facing theft, fraud, and racketeering charges for allegedly selling counterfeit MARTA Breeze cards. Breeze cards are stored-value smart cards that passengers use as part of an automated fare collection system which the Metropolitan Atlanta Rapid Transit Authority introduced to the general public in October 2006. Breeze cards are supplied by Cubic Transportation Systems, an American company that provides automated fare collection equipment and services to the mass transit industry. At the time of this slashdot submission, the Wikipedia page for the Breeze Card (last modified on 2 August 2013 at 14:52) says: 'The Breeze Card uses the MIFARE smart-card system from Dutch company NXP Semiconductors, a spin-off from Philips. The disposable, single-use, cards are using on the MIFARE Ultralight while the multiple-use plastic cards are the MIFARE Classic cards. There have been many concerns about the security of the system, mainly caused by the poor encryption method used for the cards.'"
Like everything:
If you can buy the readers, and someone obviously sells the writers somewhere, you can clone them.
As soon as you then rely on these tokens to hold individual data themselves (with no reference to a central database), then they become valued targets for attack.
If you had these cards hold nothing more than a code number, and wired all the readers to talk home, then the system can't be "scammed" as such - people can have their cards cloned, of course, but you can spot it, you can trace them, arrest them at your convenience, and give the original account holder a new card in the meantime as soon as they report the fraud. But because everything has to talk to a central database, the cards are not so much "cash" as a stolen "credit card" - traceable, and stoppable.
Then, it doesn't matter if you do use something as common as MiFare (a school I used to work in used Mifare entry systems - they weren't expensive or hard to get hold of at all and I used to program my Oyster - London Tube travel - card to open the door for me in the morning if I'd forgotten my ID card). As soon as the readers are that commonplace, the writers will be available even if that means people are building their own and making fake "cards" the size of a Raspberry Pi with some RF circuitry to pretend to be a card. The next step is just a matter of shrinking the device.
MiFare is long-cracked. You can buy the cards for pence each and the readers (direct to USB, etc.) for a pittance. The next step up is no harder than going from magstripe readers and cards up to magstripe writers with the correct magstripe "level" to read/write the banking data on an old magstripe credit card.
Don't put "value" into a chip that can be cloned. Put the value into a central, monitored, system, and provide people only with a codenumber to access it. That codenumber can be cloned still, sure, but then you can watch out for it, notice it, blacklist it, catch people red-handed. And they can't go spending "free money" offline from your system.
This is my biggest bugbear with London's Oyster system. It's just a number for the most part, but they try to store "value" on the cards and let you buy newspapers with them. Now you have an offline, valued, unmonitored, commodity on an easy-to-clone chip.
Out of curiosity, how much revenue comes in from fares, and how much expense goes out in fare maintenance?
A lot of metro systems charge fares in addition to getting public support from taxes. Has anyone thought to tally the costs of the fare system compared to the income? Things like cost of the machines, maintenance of the machines, maintenance of the turnstiles, accounting, law enforcement &c... all these things add up.
Even if the fares bring in revenue, it's probably minor. Most of the cost goes into collecting the fares, so most of that value is wasted.
The economy would get a boost if that money were freed up to be spent by consumers, and doing so would help the people who need it the most (ie - poor people).
This whole thing seems like a fabricated problem - a system that forces people to spend money just for the sake of spending it. Then spend more money reimplementing the system when the original system is found to have flaws, then spend countless hours and resources in enforcement and prosecution.
Just get rid of it. Let the money go into the economy.