|
Magnetic Stripe
Magnetic stripe technology records
magnetic data that is generally
encoded on the front or back of
a
paper or plastic card similar to that of an audio or
videotape. A magnetic stripe reader decodes the magnetic
information on the card and translates it into ASCII
characters. The magnetic stripe found on the back of
credit cards and ID badges have a possibility of up
to three "tracks" of data - Track 1, Track 2, and Tack
3. Each track has a different encoded format. Track
1 contains up to 79 alphanumeric characters while Track
2 and 3 contain only numeric characters. Track 2 contains
40 numeric characters, and track 3 contains 105 numeric
characters. The banking industry use Tracks 1 and 2.
Regulations required the customer's name to be encoded
on the magnetic stripe along with the account number.
In addition, the card holder number and expiration
date are usually encoded. ID badges, on the other hand,
use Track 2.
There are two types of magnetic encoding schemes:
low-coercivity and high-coercivity. In regards to magnetic
stripe technology, coercivity is the opposing magnetic
intensity that must be applied to a material to remove
the residual magnetism when it has been magnetized
to saturation. In other words, a card encoded with
high-coercivity has a less of a chance of accidentally
being erased with, for example, a magnetized screw
driver or magnetic clasp than a low-coercivity encoded
card. Most card systems support both types of media,
but high-coercivity is generally recommended especially
for creating ID badges.
The best known applications for magnetic stripe
are credit cards, time and attendance, personnel identification,
and banking cards. Standards have been adopted for
data densities, encoding methods, data content, recording
qualities, and data formats. Magnetic stripe standards
are mandatory in all financial systems, however, few
standards exists for most other applications.
|