[Next]
[Up]
[Previous]
Next:
Key Management
Up:
Technology Tools for
Previous:
Biometric User Authentication
As was mentioned in the section on user authentication, one common
form of authentication is to rely on something the user possesses,
such as a key or token. Tokens can be either smart or dumb, depending
on whether they contain processing power. Examples of dumb tokens are
standard magnetic strip cards, picture badges, or keys. While they
can be quite useful for user identification, dumb tokens are fairly
useless for data authentication functions.
Tokens with processing power and storage capabilities can take various
form factors. These include:
- smart cards
- In this paper I use the term ``smart card'' to
describe an ISO-standard smart card with the exact same size and shape
as a standard credit card, but with an embedded microprocessor and I/O
channel. France seems to be ahead of the rest of the world in
developing smart card technology, and they are starting to be used for
several applications. ISO standard smart cards can be
inserted thousands of times into a standard reader that connects to a
serial port of a personal computer. They are extremely convenient,
since they can easily be carried in a wallet, and can be combined with
a magentic strip or printed picture on the card to create a very
secure identification device. The major disadvantage at present is
that there are relatively few reader devices in the US at present, but
the reader devices are extremely cheap, costing less than $100 each.
- PCMCIA cards
- Unlike smart cards, PCMCIA cards are much thicker,
and have much more flexibility in the kind of technology that can be
incorporated into the cards. A type II card (the most common) is
approximately the same dimensions as a credit card, with the exception
that they are about 1/8" thick. Almost all laptop computers are now
being sold with at least one PCMCIA slot in it, so the technology is
becoming fairly common. One disadvantage of PCMCIA cards is
that the technology is not intended for as many insertions into a
reader as an ISO standard smart card, since it relies upon pins rather
than smooth contacts. Another disadvantage is the fact that PCMCIA cards
are inconvenient for carrying in wallets.
- SmartDisk[+]
- The
SmartDisk looks exactly like a standard 3.5" floppy diskette, but
instead of containing a spinning magnetic medium, it uses a magnetic
read/write head to communicate with a host computer. Inside the 3.5"
floppy disk is space for quite a bit of sophisticated electronics,
including batteries, megabytes of memory, and powerful
microprocessors. Fischer now markets a card that can be used to
control the booting of workstations, but they are also developing a
cryptographic module. The major advantage of the SmartDisk is that
virtually every desktop computer in existence has a reader already in
place that can read the SmartDisk. The SmartDisk is somewhat larger
than a smart card however, and must therefore be considered somewhat
more inconvenient.
[Next]
[Up]
[Previous]
Next:
Key Management
Up:
Technology Tools for
Previous:
Biometric User Authentication
Kevin S. McCurley
Sat Mar 11 16:00:15 MST 1995