Credit Card Magstripe Spoofer - MagSpoof
MagSpoof is a device that can spoof/emulate any magnetic stripe or credit card. It can work “wirelessly”, even on standard magstripe/credit card readers, by generating a strong electromagnetic field that emulates a traditional magnetic stripe card.
MagSpoof does not enable you to use credit cards that you are not legally authorized to use. The Chip-and-PIN and Amex information is not implemented and using MagSpoof requires you to have/own the magstripes that you wish to emulate. Simply having a credit card number and expiration is not enough to perform transactions. MagSpoof does allow you to perform research in other areas of magstripes, microcontrollers, and electromagnetism, as well as learn about and create your own devices similar to other existing, commercial technologies such as Samsung MST and Coin.
º Allows you to store all of your credit cards and magstripes in one device
º Works on traditional magstripe readers wirelessly (no NFC/RFID required)
º Can disable Chip-and-PIN (code not included)
º Correctly predicts Amex credit card numbers + expirations from previous card number (code not included)
º Supports all three magnetic stripe tracks, and even supports Track 1+2 simultaneously
º Easy to build using Arduino or other common parts
How MagSpoof Works
MagSpoof emulates a magnetic stripe by quickly changing the polarization of an electromagnet, producing a magnetic field similar to that of a normal magnetic stripe as if it’s being swiped. What’s incredible is that the magstripe reader requires no form of wireless receiver, NFC, or RFID — MagSpoof works wirelessly, even with standard magstripe readers. The stronger the electromagnet, the further away you can use it (a few inches in its current iteration).
MagSpoof also uses inexpensive, off the shelf parts, and can be built with almost nothing more than an Arduino, wire and a battery! I use a motor driver to provide a reasonable amount of power.
Normally electromagnets have an iron core, however we lose the core for the sake of space and portability. Also, while the iron core does make the electromagnet more efficient, we still produce more than enough power to work.
MagSpoof improves on new cards such as Coin. I’m a customer of Coin, and while I love their app and the card, the card actually works a very small percentage of the time. After looking over Coin’s FCC docs, I noticed they use two coils to produce a (very small) electromagnetic field, however it’s severely deficient and the card works less than 50% of the time for me, sadly.
I found that by emulating a card with MagSpoof, if I send Track 1 one way, and then send Track 2 reversed, every card reader will assume I simply swiped a card back and forth, use the data from both tracks and my strong electromagnet, and properly read all of the data. This is extremely effective, uses only a single coil, and works for both tracks simultaneously. This also allows MagSpoof to work on Track 3.
Additionally, if you’re using a Chip card with Coin, you still need to bring your actual credit card to dip, however because MagSpoof can disable Chip-and-PIN (see below), it does not require you to bring your card with you.
Hardware
º Atmel ATtiny85 (microcontroller)
An Atmel ATtiny85 is the microcontroller to drive the entire system. It stores all of the magnetic stripe / credit card data. In a thinner, credit-card sized (0.8mm thick!) version, I use an [ATtiny10].
º L293D H-Bridge (motor driver)
I use an L293D H-bridge to drive the electromagnet. The L293D is a motor driver, but motors are actually driven by the electromagnet(s) and magnets inside of them. Any standard driver should work here. Technically the L293D doesn’t work down at 3.7V (voltage of the LiPo battery), but it works surprisingly well. In the credit-card size version, I suggest using a the TI DRV8835 or TI DRV8833.
º 24AWG Magnet Wire (coil)
I use somewhere around ~24AWG magnet wire to act as the coil to produce the electromagnetic field. This piece of wire incredibly produces an electromagnetic field that makes the card reader believe a card is being swiped. Incredible. By rapidly controlling the polarization of this field, the magstripe reader believes the flipped bits of a real card are being swiped through the reader.
º 100mAh 3.7V LiPo battery (the powah)
A small 100mAh 3.7V lipo battery powers our contraption. For the credit card size version (not shown here), I use a battery from PowerStream.
º 100µF Capacitor
Keep enough energy in this capacitor to provide the electromagnet with power when we need it, otherwise it will pull too much current and reset the microcontroller. This is the capacitor kit I use as it has all the standard values I’d need.
º LED
To signal to us when we transmit information. I use this LED kit as it has a nice variety of LEDs.
º 100Ω Resistor
Don’t burn out the LED.
º Momentary Switch
Initiate the electromagnet.
º Mini-Protoboard
For soldering everything together.
MagSpoof is compatible with the Arduino framework and can work on traditional Arduinos as well as ATtiny chips.
Resources
You can learn about magnetic stripes and credit cards from a few places, including:
ISO/IEC 7810
ISO/IEC 7811
ISO/IEC 7812
ISO/IEC 7813
ISO 8583
ISO/IEC 4909
MagTek Magnetic Stripe Standards (pdf)
Magnetic Stripe Card on Wikipedia
Amex’s Web Services Plural Interface
