Smart card aims to fight fraud

[Markus Kuhn]

Peter Fairbrother wrote on 2002-03-13 15:29 UTC:
> http://news.bbc.co.uk/hi/english/sci/tech/newsid_1867000/1867073.stm
> Perhaps they have small electromagnets in the stripe that are only activated
> for a minute or so.

It is certainly not particularly difficult to have in a card a single
coil that controlled by a µC continuously repeats the flux density
changes that swiping a card at a typical speed would generate at the
read head. The idea of a magnetic media emulation interface itself is
not new. Smartcard readers that fit into a floppy drive and interface to
the PC via a coil, the floppy drive read/write head and the drive
controller have been on the market for at least half a decade:

http://www.controlbreak.net/products/smarty.html
http://www.byte.com/art/9706/sec17/art2.htm

Credit cards are normally only 0.8 mm thick, and the suggested design
would need a power supply (battery). To be swipable through most
terminals, it would be sufficient though if only half the card width had
the standard thickness, the rest could be far fatter and house keyboard,
LCD, battery. Unfortunately, the report comes without a photo of a real
PrivaSys card to confirm this.

Clouse-coupled contactless smartcards work almost the same way, except
that they also get their power supply out of the card terminal, because
the terminal was designed to talk to a microprocessor. I think, that's
in the long run going to be the more economic approach.

Markus

-- 
Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
Email: mkuhn at acm.org,  WWW: <http://www.cl.cam.ac.uk/~mgk25/>