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Daniel Cuthbert
Ever wondered what lies beneath that cool looking chip on your bank card? What does it do? Why is it there? Well here's a little pointless thread that delves into the magic using my card as an example
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
Firstly, the chip is called an EMV chip, where E is Europay, M is Mastercard and V is, you guessed it, Visa. The specifications for the chip were published in 1996. The Fugees "Killing Me Softly with His Song", was really popular too
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
This chip is actually a really powerful computer. It helps with cryptographic processing (payments) and can store data. It works when you touch it against a contactless reader using Near-field communication (NFC), or inserting it into a device (old skool baby)
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
The above is specified by two standards: ISO/IEC 7816: Identification Cards –Integrated Circuit(s) Cards ISO/IEC 14443: Identification Cards –Contactless Integrated Circuit(s)Cards –Proximity Cards
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
Sadly these standards cost a fortune to read, which is counterproductive. Standards should be open to all, not only to those who can afford them.
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
On the Integrated Circuit (IC), you'll find a Smart Card Operating System (COS) and is a micro operating system. For the electronic enthusiasts out there, this is how the pins look.
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
So what happens when you tap your card or plug it in? Well this is something that always interested me when buying coffee and the flow is as follows: 1: Activation (turn it on) 2: Exchange info 3: Deactivation (turn it off)
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
Activation is cool as it applies power to boot the chip up using a minimum value of 1 MHz and max value of 5 MHz and looks like this
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Daniel Cuthbert Oct 8
Replying to @Blackhat
for step 2, the chip uses Application Protocol Data Unit (APDU) to send data. Ivan Buetler did a brilliant talk in 2008 at on this protocol
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Daniel Cuthbert Oct 8
Replying to @monzo
So what does this super computer look like? Well here's an X-ray of my card. You can see the coils of wire used to produce electromagnetic waves, which can then be picked up and turned back into current by a another coil of wire. You can also see the bonding wires.
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Daniel Cuthbert Oct 8
Replying to @dcuthbert
I appreciate this is all rather nerdy and pointless, but a lot of work is going into what the next generation of EMV chips look like, as our payment methods change. It's a pretty exciting time when it comes to payments and contactless.
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