Researchers at Ruhr University of Bochum in Germany have been busy working with RFID and related devices for quite some time now. They call the fruit of their labors Chameleon, a versatile Contactless Smart Card Emulator. Contactless Smart Cards are RFID style devices that also contain a smart card style memory. These cards are often used for payment, replacing mag strip style credit cards. Philips MIFARE Classic cards are a common example of contactless smart cards. The Chameleon is set up to emulate any number of cards using the common 13.56MHz frequency band. Adding a new card is as simple as loading up a new CODEC and application to the firmware. Currently Chameleon can emulate MIFARE cards using the ISO14443A.
The Chameleon is completely open source, and can be built for around $25 USD. The heart of the system is an Atmel ATxmega192A3 microcontroller. The 192 is a great microcontroller for this task because it contains hardware accelerators for both DES and AES-128. An FTDI USB interface chip is used to provide an optional communication link between a host computer and the ATxmega. The link can be used for debugging, as well as manipulating data in real-time. A host PC is not necessary for use though – the Chameleon will operate just fine as a stand alone unit. We definitely like this project – though we’re going to be doubling down on the shielding in our RF blocking wallets.
[Milosch] wrote in to tell us that he has recently released a bootable RFID live hacking system – something he has been diligently working on for quite some time. The live distro can be used for breaking and analyzing MIFARE RFID cards, as well as a reasonable selection of other well-known card formats. The release is based off the Fedora 15 live desktop system, and includes a long list of RFID hacking tools, as well as some applications that allow for NFC tag emulation.
His toolkit also contains a baudline-based LF RFID sniffer package, allowing for a real-time waveform display of low frequency RFID tags. The LF sniffer makes use of a cheap USB sound card, as well as a relatively simple reader constructed from a handful of easy to find components.
We have seen some of [Milosch’s] handiwork before, so we are fairly confident that his toolkit contains just about everything you need to start sniffing and hacking RFID tags. If you’re interested in grabbing a copy of the ISO, just be aware that the live CD is only compatible with 64-bit systems, so older laptops need not apply.
[Benjamin Blundell] built an RFID reader for the iPhone. A jailbroken iPhone connects to this project box by patching into a standard iPhone USB cable. Like in past iPhone serial projects, [Benjamin] is using openFrameworks for the software interface. Right now this reader only detects low-frequency tags but he’s working on the code to read MIFARE tags as well. See the magic of a tag ID displayed on the screen in the video after the break.
When we first saw [Chris Paget]’s cloning video, our reaction was pretty ‘meh’. We’d seen RFID cloning before and the Mifare crack was probably the last time RFID was actually interesting. His ShmooCon presentation, embedded above, caught us completely off-guard. It’s very informative; we highly recommend it.
The hardest part about selling this talk is that it has to use two overloaded words: ‘RFID’ and ‘passport’. The Passport Card, which is part the the Western Hemisphere Travel Initiative (WHTI), is not like the passport book that you’re familiar with. It has the form factor of a driver’s license and can only be used for land and sea travel between the USA, Canada, the Caribbean region, Bermuda, and Mexico. They’ve only started issuing them this year.
The Massachusetts Bay Transit Authority (MBTA) has dropped its federal case against three MIT researchers, “the subway hackers”. This happened in October and now the EFF brings news that the students will be working with the MBTA to improve their system. The overall goal is to raise security while keeping expenses minimal.
This whole mess started in August when a gag order was issued against the students’ presentation at Defcon. It’s a shame no one ever saw it because it covers a lot of interesting ground. A PDF of the banned slides is still online. They performed several attacks against both the subway’s fare system and physical security. Our favorites by far were using GNU Radio to sniff the RFID card’s transaction and bruteforcing Mifare Classic with an FPGA.
[Karsten Nohl] has recently joined the team on Flylogic’s blog. You may remember him as part of the team that reverse engineered the crypto in MiFare RFID chips. In his first post, he starts out with the basics of identifying logic cells. By studying the specific layout of the transistors you can reproduce the actual logic functions of the chip. The end of post holds a challenge for next week (pictured above). It has 34 transistors, 3 inputs, 2 outputs, and time variant behavior. Also, check out the Silicon Zoo which catalogs individual logic cells for identification.
Popular Mechanics has an interview with [Zach Anderson], one of the MIT hackers that was temporarily gagged by the MBTA. The interview is essentially a timeline of the events that led up to the Defcon talk cancellation. [Zach] pointed out a great article by The Tech that covers the vulnerabilities. The mag stripe cards can be easily cloned. The students we’re also able to increase the value of the card by brute forcing the checksum. There are only 64 possible checksum values, so they made a card for each one. It’s not graceful, but it works. The card values aren’t encrypted and there isn’t an auditing system to check what values should be on the card either. The RFID cards use Mifare classic, which we know is broken. It was NXP, Mifare’s manufacturer, that tipped off the MBTA on the actual presentation.