Applications and the Future - Codes: The Guide to Secrecy from Ancient to Modern Times - page 353

9.3 Smart Cards
As a human being, one has been endowed with just enough intelligence to be
able to see clearly how utterly inadequate that intelligence is when confronted
with what exists.
Albert Einstein (1879-1955)
— from a letter to Queen Elizabeth of Belgium, September 19, 1932
The term “smart card” has entered our discussions briefly thus far (see pages
105 and 334, for instance). Now it is time to delve into the details.
What is a Smart Card? Smart cards are made of plastic and are of
credit-card-size, havingan embedded microprocessor chip with internal memory
or merely a memory chip with nonprogramming logic. 9.25
Types of Smart Cards : Classifications for smart cards is described in the
following.
1. Standard Memory Cards : These are cards that merely store data. They
do not possess data-processingcapabilities. Typically, these cards have
a magnetic strip (so are often called magnetic strip cards ). These cards
store private data, usually employed as credit or debit cards, which require
physical contact with a device to read the data on the magnetic strip.
2. Intelligent Memory Cards : These cards have a built-in wired logic circuit
to access the memory (usually 1 K to 16 K bits) of the card. Sometimes
these cards can be configured to restrict access via a password or system
key. These cards are often called protected memory cards .
3. Stored-Value Cards : Sometimes these are called memory cards with
register . These are cards that have security features hard-wired into
the chip at the point of manufacture. Examples of such cards are prepaid
phone cards, wherein a terminal inside the pay phone will write a declining
balance into the card's memory. The card is discarded when the balance
is zero; or if the card has a rechargeable capacity, it can be reset.
4. Processor Cards : These cards, perhaps the most deservingof the name
smart card , contain memory, a processor, and have data-processingca-
pabilities. This is an integrated circuit (IC) card with ISO/IEC 7816
interface. 9.26 If an 8-bit microprocessor had the task of RSA crypto-
graphic calculations, for instance, it could take several minutes. Thus, a
9.25 A microprocessor is any integrated circuit (IC) containing the CPU of a small computer.
A CPU is the Central Processing Unit , which controls the operation of a computer, including
the execution of arithmetic and logical operations as well as other instructions. In a smart
card or microcomputer, the entire CPU is on a single chip. In general a computer processor
is the logic circuitry that responds to and deals with the instructions that run the computer.
However, in the modern day, the term “processor” has been replaced by “CPU”.
9.26 We learned about the ISO on page 218. The IEC is the International Electrotechnical
Commission , a Switzerland-based organization that sets standards for electronic devices. A
committee, JTC1, is joint between ISO and IEC, and its mandate is information technology
standardization.