10/28/2011 Smart Card Primer
A smart card is a device that includes an embedded integrated circuit
chip (ICC) that can be either a secure microcontroller or equivalent
intelligence with internal memory or a memory chip alone. The card
connects to a reader with direct physical contact or with a remote
contactless radio frequency interface. With an embedded microcontroller,
smart cards have the unique ability to store large amounts of data,
carry out their own on-card functions (e.g., encryption and mutual
authentication) and interact intelligently with a smart card reader.
Smart card technology conforms to international standards (ISO/IEC 7816
and ISO/IEC 14443) and is available in a variety of form factors,
including plastic cards, fobs, subscriber identity modules (SIMs) used
in GSM mobile phones, and USB-based tokens.
Smart Card Technology
There are two general categories of smart cards: contact and contactless.
A contact smart card must be inserted into a smart card reader with a
direct connection to a conductive contact plate on the surface of the
card (typically gold plated). Transmission of commands, data, and card
status takes place over these physical contact points.
A contactless card requires only close proximity to a reader. Both
the reader and the card have antennae, and the two communicate using
radio frequencies (RF) over this contactless link. Most contactless
cards also derive power for the internal chip from this electromagnetic
signal. The range is typically one-half to three inches for
non-battery-powered cards, ideal for applications such as building entry
and payment that require a very fast card interface.
Two additional categories of cards are dual-interface cards and
hybrid cards. A hybrid card has two chips, one with a contact interface
and one with a contactless interface. The two chips are not
interconnected. A dual-interface card has a single chip with both
contact and contactless interfaces. With dual-interface cards, it is
possible to access the same chip using either a contact or contactless
interface with a very high level of security.
The chips used in all of these cards fall into two categories as
well: microcontroller chips and memory chips. A memory chip is like a
small floppy disk with optional security. Memory chips are less
expensive than microcontrollers but with a corresponding decrease in
data management security. Cards that use memory chips depend on the
security of the card reader for processing and are ideal for situations
that require low or medium security.
A microcontroller chip can add, delete, and otherwise manipulate
information in its memory. A microcontroller is like a miniature
computer, with an input/output port, operating system, and hard disk.
Smart cards with an embedded microcontroller have the unique ability to
store large amounts of data, carry out their own on-card functions
(e.g., encryption and digital signatures) and interact intelligently
with a smart card reader.
The selection of a particular card technology is driven by a variety of issues, including:
- Application dynamics
- Prevailing market infrastructure
- Economics of the business model
- Strategy for shared application cards
- Secure identity applications – employee ID badges, citizen ID documents, electronic passports, driver’s licenses, online authentication devices
- Healthcare applications – citizen health ID cards, physician ID cards, portable medical records cards
- Payment applications – contact and contactless credit/debit cards, transit payment cards
- Telecommunications applications – GSM Subscriber Identity Modules, pay telephone payment cards