Magnetic stripe card

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(Created page with " Magstripe (magnetic-stripe) cards are everywhere: bank cards, hotel cards, gift cards, transit ticket, id cards. They encode machine-readable data in a strip of magnetized ma...")
 
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Magstripe (magnetic-stripe) cards are everywhere: bank cards, hotel cards, gift cards, transit ticket, id cards. They encode machine-readable data in a strip of magnetized material, usually located next to the long edge of the card. They most commonly appear in the approximate size and shape of a credit-card, though airline boarding passes, mass-transit fare cards, and many other varied forms exist. The underlying technology is the same, though: a sequence of alternately-polarized magnetic stripes which are read with a magnetic head similar to that found in any cassette player.
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Magstripe (magnetic-stripe) cards are everywhere: bank cards, [http://cansecwest.com/slides06/csw06-malfunction.pdf hotel key cards], gift cards, transit ticket, id cards. They encode machine-readable data in a strip of magnetized material, usually located next to the long edge of the card. They most commonly appear in the approximate size and shape of a credit-card, though airline boarding passes, mass-transit fare cards, and many other varied forms exist. The underlying technology is the same, though: a sequence of alternately-polarized magnetic stripes which are read with a magnetic head similar to that found in any cassette player.
  
Encoding of data varies, possibilites include:
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Data formats:
 
* [[ISO/IEC_7813]]
 
* [[ISO/IEC_7813]]
 
* [[ANSI/ISO ALPHA Data Format]]
 
* [[ANSI/ISO ALPHA Data Format]]
 
* [[ANSI/ISO BCD Data Format]]
 
* [[ANSI/ISO BCD Data Format]]
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[http://www.alcrypto.co.uk/magstripe/dmsb.py python script to decod
  
  
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Magnetic card readers capable of decoding the data formats used for credit cards are available pretty cheaply on the Internet, but for arbitrary formats you might need the raw data on the card. It's pretty easy to build a reader that uses a soundcard's DAC to capture the signal, by wiring a tape-head from a cassette player to an audio plug, and using a ruler to line up the tape head as you run it along the desired track. ([http://www.gae.ucm.es/~padilla/extrawork/soundtrack.html more detailed instructions])
 
Magnetic card readers capable of decoding the data formats used for credit cards are available pretty cheaply on the Internet, but for arbitrary formats you might need the raw data on the card. It's pretty easy to build a reader that uses a soundcard's DAC to capture the signal, by wiring a tape-head from a cassette player to an audio plug, and using a ruler to line up the tape head as you run it along the desired track. ([http://www.gae.ucm.es/~padilla/extrawork/soundtrack.html more detailed instructions])
  
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== Binary encoding ==
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Modern cards are usually [[Aiken Biphase]].
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[http://www.alcrypto.co.uk/magstripe/dab.py Python script to decode Aiken Biphase from a WAV file]
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[http://www.phrack.org/archives/37/p37_0x06_Card-O-Rama:%20Magnetic%20Stripe%20Technology%20and%20Beyond_by_Count%20Zero.txt Count Zero's canonical walkthrough of magstripe technology from Phrack 37]
  
 
== More sources ==
 
== More sources ==
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* [http://en.wikipedia.org/wiki/Magnetic_stripe_card Wikipedia page] has good details
 
* [http://en.wikipedia.org/wiki/Magnetic_stripe_card Wikipedia page] has good details
 
* [http://www.abacus21.com/Magnetic-Strip-Encoding-1586.html Magnetic Strip Encoding Standards]
 
* [http://www.abacus21.com/Magnetic-Strip-Encoding-1586.html Magnetic Strip Encoding Standards]
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* [http://www.hhhh.org/~joeboy/resources/magcards/]
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* [http://www.ded.co.uk/magnetic-stripe-card-standards/]
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* [http://www.quora.com/When-was-the-first-credit-card-with-a-magnetic-stripe-issued/answer/Brian-Roemmele history of the magstripe card]
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* [http://www.gae.ucm.es/~padilla/extrawork/stripe.html collection of resources]
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* [http://www.textfiles.com/anarchy/CARDING/ Textfile.com things related to cloning cards]

Revision as of 06:23, 1 November 2012

Magstripe (magnetic-stripe) cards are everywhere: bank cards, hotel key cards, gift cards, transit ticket, id cards. They encode machine-readable data in a strip of magnetized material, usually located next to the long edge of the card. They most commonly appear in the approximate size and shape of a credit-card, though airline boarding passes, mass-transit fare cards, and many other varied forms exist. The underlying technology is the same, though: a sequence of alternately-polarized magnetic stripes which are read with a magnetic head similar to that found in any cassette player.

Data formats:

[http://www.alcrypto.co.uk/magstripe/dmsb.py python script to decod


Making a reader

Magnetic card readers capable of decoding the data formats used for credit cards are available pretty cheaply on the Internet, but for arbitrary formats you might need the raw data on the card. It's pretty easy to build a reader that uses a soundcard's DAC to capture the signal, by wiring a tape-head from a cassette player to an audio plug, and using a ruler to line up the tape head as you run it along the desired track. (more detailed instructions)

Binary encoding

Modern cards are usually Aiken Biphase.

Python script to decode Aiken Biphase from a WAV file

Count Zero's canonical walkthrough of magstripe technology from Phrack 37

More sources

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