What are Smart Cards ?
Smart Cards, in Europe also called ChipCards, are
plastic cards with an embedded chip (or Integrated Circuit, IC).
They can be categorized according to interface technology and chip/IC
characteristics.
Interface technology and Contact Smart Cards
The connection between the IC on the card and the
card reader (today all readers can also write) is done through
mechanical contacts. Smart card ICs are packaged in specialized "modules" that
protect the silicon (i.e. the IC) from mechanical stress and allow
metal contacts, planar to the card surface, to connect to the pads
on the silicon. In the card manufacturing process the module is
glued into a cavity that has been milled into the plastic card.
Contact-less Smart Cards The IC in the card communicates
via electromagnetic fields with the reader using an antenna that
is inserted in the card. The antenna is connected with a specialized
module that encapsulates the IC. Contact-less cards usually cannot
be identified from the outside as such. All of the "smarts" are
hidden inside. The two main frequencies used are 125 khz and 13.56
Mhz, the latter being the more recent technology.
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SCM USB Card Reader for Windows XP
Hybrid cards
There are two main types of hybrid cards:
* Dual chip: a contact module is inserted into
a contact less card. Both chips cannot interface with each other.
* Dual interface cards: a single chip can handle
both interfaces. The first versions of this technology used hard
wired logic for the wireless interface and a microprocessor for
the contact interface. Newer versions have the microprocessor also
handle the wireless interface.2. IC characteristics.
Memory Cards
Comparable with a floppy disk. It uses EEPROM (electrically
erasable programmable read only memory) non-volatile memory technology
(usually according to the I2C interface standard) that allows a
user to read and write data to the card. There is no protection
of access to the data possible.
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Secure Memory Cards
Also use EEPROM for the actual data storage. Various
configurations are available that use hard-wired logic to restrict
data access (read and/or write) with PINs. In some cases authentication
of the card to the system is handled with proprietary challenge-response
algorithms. Additionally coding of the cards in the PROM/OTP (programmable
read only memory/one time programmable) can further reduce counterfeiting
of legitimate cards.
Microprocessor Cards
Dominate the trend in smart card technology (these
are the actual SMART cards) they are predominately powered be an
8-bit microprocessor that has been optimized for smart card applications,
i.e. security and data storage. The chip further contains RAM (random
access memory), EEPROM for data and application storage and ROM
for storage of the operating that instructs the processor and allows
it to run an application (secure access, e-purse, challenge response,
anti-tearing, etc.) Microprocessor cards offer the most flexible
and secure solution for most smart card programs.
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If you would like to know more about Smart card
readers an prices on some of our products please send us an e-mail
at: readers@dowrick.com
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