U.S. patent application number 09/081446 was filed with the patent office on 2001-08-09 for systems for authenticating use of transaction cards having a magnetic stripe.
Invention is credited to KRAUSE, ARTHUR.
Application Number | 20010011684 09/081446 |
Document ID | / |
Family ID | 23542876 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010011684 |
Kind Code |
A1 |
KRAUSE, ARTHUR |
August 9, 2001 |
SYSTEMS FOR AUTHENTICATING USE OF TRANSACTION CARDS HAVING A
MAGNETIC STRIPE
Abstract
Transaction cards operable as "smart cards"; credit cards; debit
cards; access cards; et cetera, having an self-enabling and
self-disabling feature provides for authentication and proper user
verification. The card receives input from a user and determines if
the input is valid. If the user input is valid, the card responds
by enabling a magnetic stripe thereon. The magnetic stripe is
enabled for a limited time after which it is then disabled. A
disabled magnetic stripe is then inoperable for activating card
readers. A card which is lost or stolen cannot be used by
unauthorized users as it would have a magnetic stripe in a disabled
state and only an authorized user would have the ability to enable
it. The card possesses a high level of compatibility with known
methodology in the art and does not require additional equipment
and systems to attain its high security level.
Inventors: |
KRAUSE, ARTHUR; (CANOGA
PARK, CA) |
Correspondence
Address: |
DENNIS H. LAMBERT
DENNIS H. LAMBERT & ASSOCIATES
7000 VIEW PARK DRIVE
BURKE
VA
22015
US
|
Family ID: |
23542876 |
Appl. No.: |
09/081446 |
Filed: |
May 19, 1998 |
Current U.S.
Class: |
235/492 |
Current CPC
Class: |
G07F 7/1058 20130101;
G06Q 20/341 20130101; G06Q 20/347 20130101; G07F 7/1025 20130101;
G07F 7/10 20130101; G07F 7/1008 20130101; G06K 7/084 20130101; G06Q
20/3415 20130101 |
Class at
Publication: |
235/492 |
International
Class: |
G06K 019/06 |
Claims
We claim:
1. A transaction card comprised of a magnetic stripe which may be
disabled via an internal transducer.
2. A transaction card of claim 1 which is comprised of a magnetic
stripe that is responsive to user activity, where the magnetic
stripe is magnetic media operable for maintaining magnetic fields
and having the ability to have its magnetic state changed in
response to correct entry of a predetermined code.
3. A transaction card of claim 2, where responsive includes
enabling and disabling the magnetic stripe, and where user activity
includes tactile entry of a code or identification number.
4. A transaction card of claim 1 comprised of: an energy source; a
keypad; a logic processor; a transducer; and a magnetic stripe,
each incorporated into the card.
5. A transaction card of claim 4, said energy source being a
battery in electrical contact with said logic processor; said
keypad being a plurality of switches operable for converting
tactile user input into an electrical signal processable by; said
logic processor being a microcircuit operable for receiving the
electrical signal, comparing it to a stored code, and enabling said
transducer in accordance with that comparison; said transducer in
communication with said logic processor being an electrical
conductor operable for converting electrical energy to magnetic
energy in a spatial pattern; said magnetic stripe in proximity and
responsive to said transducer being operable for maintaining a
magnetic field thereon.
6. A transaction card of claim 5, said energy source further
comprising a thin, flat energy cell having a thickness less than
about 3 mm and greater than about 0.2 mm whereby the cell can be
incorporated between the two flat surfaces of a standard
transaction card; said keypad further comprising a thin, flat
element having a plurality of switches, each switch being operable
for providing a unique signal to the logic processor; said logic
processor further comprising a microcircuit having: a first portion
operable for receiving user inputs; a second portion for storing
and recalling a reference code; a third portion in communication
with the first and second portions operable for executing a logic
program including comparing user inputs to reference codes; a
fourth portion for generating an enable signal in accordance with
the comparison; and a fifth portion in communication with the
transducer operable for delivering the enable signal thereto; said
logic processor being a microcircuit operable for receiving the
electrical signal, comparing it to a stored code, and enabling said
transducer in accordance with that comparison.
7. A transaction card of claim 1 comprised of: an energy receiving
means; a keypad; a logic processor; a transducer; and a magnetic
stripe, each incorporated into the card.
8. A transaction card of claim 7, said energy receiving means being
an electrical conductor in communication with the logic processor
and having contacts which are accessible to the cards exterior.
9. A method of authenticating a transaction card having a magnetic
stripe responsive to user activity comprising the steps: a)
receiving user input; b) comparing the user input to a stored
reference signal; and c) enabling a magnetic media in accordance
with said comparison with prescribed data.
10. A method of claim 9, said receiving user input step further
comprising receiving an electrical signal representing a user input
at a logic processor; said comparing the user input to a stored
reference signal step further comprising determining if a
coincidence exists between the user input and the stored reference
signal; said enabling a magnetic media with prescribed data step
further comprising writing a magnetic signal to the magnetic media
in accordance with the determination of coincidence such that if
coincidence is detected the magnetic medium is enabled with
prescribed data, and if coincidence is not detected the magnetic
medium is not enabled.
11. A method of claim 9, further comprising the steps: d) storing a
reference signal in a logic processor memory; e) initiating the
magnetic stripe in a disabled state; f) allowing a period of time
to pass; and g) disabling the magnetic stripe.
12. A method of claim 11, the a) storing a reference signal in a
memory step being further defined as: providing to a storage means,
and storing therein, a predetermined reference signal whereby
authorized persons could have knowledge of the predetermined
reference signal; the b) initiating the magnetic stripe in a
disabled state step being further defined as: applying a decreasing
amplitude sinusoidal electronic signal to a microcircuit arranged
to create a spatial distribution of magnetic fields whereby a
signal on a magnetic recording material is erased and the magnetic
material is disabled; the c) receiving user input step being
further defined as: converting a physical tactile user input at a
transduction means to an electronic signal processable by a logic
processor; the d) comparing the user input to a stored reference
signal step being further defined as: comparing the electronic
signal representing the user input to the predetermined reference
signal to detect a coincidence between those signals; the e)
enabling a magnetic media with prescribed data step being further
defined as: if a coincidence is detected, enabling the magnetic
stripe by writing a spatially modulated magnetic signal to the
magnetic stripe by applying an energetic electrical pulse to a
spatially distributed microcircuit; and if a coincidence is not
detected, take no action allowing the magnetic stripe to remain
dialed; the f) allowing a period of time to pass step being further
defined as: allowing a period of time to pass which is sufficient
for a user to use the transaction card's magnetic stripe in a
manner consistent with use of magnetic stripes, a period between 30
seconds and 5 minutes; and the g) disabling the magnetic stripe
step being further defined as: applying a decreasing amplitude
sinusoidal electronic signal to a microcircuit arranged to create a
spatial distribution of magnetic fields whereby a signal on a
magnetic recording material is erased and the magnetic material is
disabled.
Description
BACKGROUND OF THE INVENTION
[0001] This application continues from U.S. application having Ser.
No. 08/390,539 filed on Feb. 17, 1995. The disclosure of that
application is hereby incorporated by reference as if it were fully
set forth here.
[0002] This invention is generally concerned with authenticity
verification systems for use with transaction cards and is
specifically concerned with transaction cards which are operable
for self-enabling and self-disabling in response to authenticity
procedures and methods. Cards such as "smart" cards, credit cards,
debit cards, access cards, et cetera, are common forms of a general
group known as transaction cards.
[0003] Certain transactions between unfamiliar persons or
transactions between persons and machines sometimes require
security measures which provide verification of the authority of
the person making the transaction. Examples of such transactions
may include but are not limited to: access to restricted locations,
financial or "point-of-sale", simple personal identification, and
document authentication.
[0004] Secured areas may have access restrictions which limit
admission to certain persons having access authority. Sophisticated
systems which interrogate biometric features such as cornea
patterns or fingerprints have been used to identify authorized
persons for access. Similarly, valuable documents sensitive to
counterfeit may incorporate security measures which provide for
authenticity. A driver's license has a photograph to associate the
document with a particular person and to prevent use of the
document by others. Passports may include photographs and further
use of official seals or holograms to provide for authenticating
the documents. Each of the described situations have the
requirement that an authorized person be properly identified.
Whereas security for access to restricted locations typically
require extremely sophisticated verification means, and whereas
driver's license documents may be sufficiently authenticated by
simple photographs, point-of-sale (POS) transactions have features
associated therewith which are particularly suitable for certain
other security and authentication systems.
[0005] Features of POS transactions systems include: the
requirement that the system be quick and easy to use; does not
require salespersons attention or time; supports a huge number of
transactions; tamper resistant; and compatibility with common
devices presently in place, for example credit cards, debit cards
and others. Indeed, as is illustrated by recent activity in
development of various systems, great attention has been directed
to POS authentication devices and methods.
[0006] Cash has the inconvenience of being: usable if found by
others (non-criminal use); improperly counted; mislaid; stolen
(criminal use); or other misuse. It is therefore desirable to
reduce exposure to loss resulting from the use of cash by employing
another means of money transfer. Credit cards are commonly used,
but fraudulent use of credit cards is an expensive problem. Debit
cards which typically require low level identification such as
entry of a personal identification number PIN in addition to
presentation of a card with corresponding data reduces fraud but
still suffers from compromise. By watching the legitimate user
enter a PIN, a thief can acquire that code and other account
information necessary to later steal from the account. Elaborate
schemes involving fake ATM machines have also been used to obtain
account information and PIN codes. As all of these unauthorized
uses are very expensive to card issuers and ultimately to
consumers, it is desirable to increase the security of the systems.
To that end several attempts have been made to introduce new
systems to POS transactions which reduce the fraudulent use of
transaction cards.
[0007] In U.S. Pat. No. 5,180,901 inventor Hiramatsu teaches of a
pressure sensor for inputting finger characteristic data. An
authorized user having particular finger characteristics could
activate the card but others could not. Inventors Butterworth teach
of a keypad which receives a code and responds with a light signal
to indicate authenticity in U.S. Pat. No. 4,879,455. An elaborate
scheme worked out by Muehlberger in U.S. Pat. No. 5,285,382 yields
a method for processing credit and debit cards for valid use. There
is no shortage of good inventions in the field and the demand for
security is very high.
[0008] Notwithstanding, new techniques have now been discovered
which provide very novel uses of transaction cards, particularly
with respect to point-of-sale type transactions. In contrast to the
good and useful inventions mentioned, each having certain useful
features, the instant invention is concerned with the enablement
and disablement of a transaction card via writing and erasing data
to a magnetic stripe thereon the card in response to a user
input.
[0009] Systems of the invention are distinguished from those of the
prior art in that they provide a very high level of compatibility
with present standard systems in use yet provide a higher level of
security than is attainable by devices and methods of the art. In
particular, the invention provides a card which is operable for
receiving a user input, validating that input and responding to
valid input by enabling a standard format magnetic stripe, and
further operable for disabling same magnetic stripe after use
thereby preventing further use by unauthorized persons.
SUMMARY OF THE INVENTION
[0010] The invention provides for a transaction card having a
magnetic stripe which can be enabled and disabled via a transducer
incorporated into the card where the transducer is driven by a
microprocessor in response to a user input. The user input,
generally a code, serves to associate the card with its authorized
user.
[0011] Although "transaction card" generally refers to a credit or
debit type card, a transaction card of the invention can be any
document or object which benefits from a security system which
prevents unauthorized use thereof. The "magnetic stripe" is meant
to be a magnetic medium which is operable for maintaining recorded
data where the data can be written to and erased from the medium.
The "transducer" is a device which is driven by electrical signals
and provides a magnetic field or fields effective for writing data
to and erasing data from the magnetic stripe. use of the terms
"enabled" and "disabled" refer to the condition of the data on the
magnetic stripe. An "enabled" magnetic stripe has data recorded
thereon which can be read by a magnetic media scanner. A "disabled"
magnetic stripe is one having data scrambled or erased such that a
scanner cannot properly read information from the stripe. It is
important to note that "disabled" essentially refers to the data on
the stripe and not to recording mechanisms of the stripe. "user
input" refers to a code, or sequence, or personal identification
number PIN entered by way of a keypad or other user input means.
"Driven" refers to activation of the transducer to operate on the
magnetic stripe. "Response" means that the system acts in
accordance with the particular user input.
[0012] Since it is highly desirable to create a system which has
minimal or no compatibility problems with existing systems and
equipment, but one which increases the security possible therein,
the invention has been developed without the requirement of new
complicated equipment. Standard card readers presently installed in
many thousands of retail locations require data in a certain format
or formats. These formats are set forth in ISO standards and are
useful for some preferred embodiments. Some cards of the invention
are arranged to work with the presently installed card readers. It
is also desirable to provide a system without complicated steps or
steps which involve input from retailers. Methods of the invention
therefore are directed to simple operations which quickly
authenticate the card.
[0013] A transaction card user enters via a keypad integrated
therein, a code which is compared by a microprocessor to a
previously stored reference for coincidence. Detection of
coincidence results in enablement of the data on the magnetic
stripe, and lack of coincidence results in disablement of the data
on the magnetic stripe.
[0014] While the invention provides particular benefits to
transactions such as point-of-sale type financial transactions, it
may also be useful for other transactions requiring verification of
use of a object or document by authorized persons.
[0015] A primary object of the present invention to provide a
system of security for objects and documents. It is a further
object of the invention to provide security for transaction card
devices. It is further an object of the invention to provide a
transaction card security system having a high degree of
compatibility with respect to equipment, methodology, habits,
standards of existing arts. It is still further an object of the
invention to provide a card which is inexpensive to produce.
[0016] A better understanding can be had with reference to the
detailed description of preferred embodiments and with reference to
the appended drawings. These embodiments represent particular ways
to realize the invention and are not inclusive of all ways possible
to benefit from the invention. Therefore, there may exist
embodiments that do not deviate from the true scope of the
invention as set forth by the claims, but do not appear here as
specific examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features, aspects, and advantages of the
present invention will become better understood with regard to the
following description, appended claims and drawings where:
[0018] FIG. 1 is an exploded perspective view of some of the
components of a transaction card of the invention;
[0019] FIG. 2 is a diagram illustrating the interaction of electric
current with magnetic media;
[0020] FIG. 3 is similar diagram where the magnetic media is a
stripe;
[0021] FIG. 4 is a plot of applied current verses magnetic response
of a magnetic medium;
[0022] FIG. 5 is a similar plot showing the response to a special
signal having a particular time dependence;
[0023] FIG. 6 is an illustration of one version of a data
format;
[0024] FIG. 7 is a block diagram of major components of some
devices of the invention;
[0025] FIG. 8 is a flow diagram for a version of a method of the
invention.
PREFERRED EMBODIMENTS OF THE INVENTION
[0026] Transaction cards of the invention may be embodied in many
forms. In some preferred embodiments, the card may have the
identical appearance of a simple credit card except for a keypad.
Since it is an object of the invention to provide cards compatible
with presently known systems, a preferred version of the invention,
the best mode known to the inventor, is presented here as an
example.
[0027] Accordingly, and with reference to the appended drawing FIG.
1, transaction cards of certain preferred versions of the invention
have the following major components: a card 1, a magnetic medium 6,
a data track or data tracks 7, a keypad 2, a microprocessor 5, a
energy source 4, and a transducer 3. When assembled together, these
elements occupy the space between the two planar surfaces of the
card, the card being of a standard size as set forth in ISO
standards 7811/ 1-5, and others. The card 1 can be made of
inexpensive plastics or other materials compatible with
microelectronic manufacture techniques. The energy source 4 can be
a simple battery sufficient for providing energy to a
microprocessor and to a transducer 3. A microcontroller or
microprocessor 5 is a micro-integrated circuit device operable for
performing logic operations, retaining microcode type information,
executing that microcode, storing data, recalling data, comparing
data, receiving inputs from sources outside the processor,
transmitting output signals to output devices, and other functions
common to such devices. A keypad 2 is operable for transducing user
tactile input into electrical signals compatible with processing
routines of the microprocessor and is in electrical communication
therewith. Data tracks 7 are areas on the magnetic medium which
contain data in the form of spatially modulated magnetized regions.
The data tracks can be arranged in many ways, but very detailed
specifications set forth in the ISO standards suggest a format
which is desirable in best embodiments of the invention. Although
only one track is shown in the FIG. 1, cards generally have two or
three data tracks. Extension to multiple tracks is clearly
anticipated. The elements mentioned so far are known to have been
used with other transaction card type devices. The transducer 3 and
special magnetic medium 6, sometimes herein called a magnetic
stripe, are elements unique to this invention and a detailed
explanation of each follows.
[0028] The magnetic medium 6 is similar to other known magnetic
media, except that it has sensitivity properties which may be
different. In general, magnetic media of the invention has a lower
coercivity, i.e. is more responsive than comparable, frequently
used media. In a data "writing" process, normal credit cards having
a magnetic stripe are generally exposed to very strong magnetic
fields which "permanently" record data thereon. The sensitivity or
coercivity of that media is about 300 Orstead. By "permanently" it
is meant that the data is intended to be long-lived and is not
changeable from day to day by the user. Of course, the cards can be
erased and re-written but this is not a normal procedure and an
issuing institution is likely to do this operation. It is not
considered a user function or a function executed as a result of a
user action. The cards of the invention by comparison have a
"dynamic" magnetic stripe. This medium is compatible with frequent
changes in the state of the data it contains. In addition, it is
desirable to make changes to the data with small amounts of energy
to increase the life of the energy source 4. For these reasons, a
magnetic medium which has a coercivity between 3 and 200 Orstead
may be used in some preferred embodiments. Coercivities less than 3
may not be useful for maintaining data as even the Earth's magnetic
fields, fields which normal use of the cards may result in adverse
exposure thereto, and may affect the data thereon. In addition,
electrical devices used in conjunction with cards such as card
readers, scanners, electronic cash registers, et cetera, may also
expose cards to magnetic fields having a magnitude strong enough to
affect such sensitive materials. A magnetic material having a
sensitivity of 130 Orstead may be ideal as data could easily be
written with small amounts of energy and that data may be stable in
fields to which the card would normally be exposed. Other
properties and sizes of magnetic media useful in various versions
of the invention may be exactly the same as commonly used
materials. However use of the word dynamic in this disclosure means
that the magnetic stripe is writable and erasable from time-to-time
during normal use of the card. Normally, after a card becomes
within the possession of the user and the signal on the magnetic
stripe somehow changes, the card is "damaged" and becomes
inoperable.
[0029] The transducer 3 is a new device with respect to transaction
cards. Although it can be a simple electrical conductor, a wire for
example, a spatial arrangement of the conductor contains important
information. The transducer is operable for converting electrical
energy supplied by the energy source 4 into magnetic energy which
can write data to the magnetic stripe in a predetermined format. In
the simplest case, as is illustrated in FIG. 2, one can imagine a
single wire 24 in close proximity to a planar sheet 23 of magnetic
material. A current 21 passing through the wire 24 will cause a
magnetic field 22 around the wire in accordance with Maxwell's
equations. The direction of the magnetic field in the plane of the
magnetic material 23 is illustrated by the arrows 25. That is also
the direction of magnetization which will remain on the material
after the current ceases. The example in FIG. 2 is then expanded to
a more complicated illustration in FIG. 3. A second wire is
introduced to the scheme and the magnetic material is extended into
a long rectangular format or a stripe 31. By clever arrangement,
the second wire can have a current passing therethrough in the
opposite direction compared to the first wire, thus causing a
magnetic field 33 in the opposite direction. Accordingly, the
"recorded" field 35 is opposite in direction to the "recorded"
field 34. These fields may remain on the stripe even after the
currents are removed. This can be further understood from the well
known plot of current 42 verses magnetic field 43 for magnetic type
materials illustrated in FIG. 4. If an applied current causes a
magnetic field strong enough to reach the saturation point 44 of
the material, and then the current is removed, the magnitude of the
resultant magnetic field remaining on the material will be
indicated by the vector 41.
[0030] The removal of a magnetic field from a magnetic material is
also of great interest to the present invention. FIG. 5 shows a
current pulse 51 as a function of time that is sinusoidal and
continuously decreasing in amplitude. The same plot of applied
current 52 verses resultant magnetic field 53 yields a curve as
shown 54. After such signal is applied to either wire, the field
remaining on the magnetic material is negligible. Application of a
pulse as described is sometimes herein referred to as "erasing" or
"disabling" the data on the medium. One could easily appreciate
that by connecting the two wires of FIG. 3 at the tops thereof, an
applied current will pass through one wire first and the other wire
second in directions appropriate to cause the fields shown. This
can be repeated many times along the stripe to create a circuit of
wire having a single current which produces fields on the stripe in
various locations.
[0031] The exact locations of the wires can be manipulated to form
some desired spatial pattern. Indeed, the spatial pattern on
magnetic stripes is well known to be useful for encoding said
stripes with digital information relating to the function of the
cards containing such stripes. The ISO standards for transaction
cards call for a character of five bits, four data bits and a
parity bit. To provide for a transducer which is capable of
recording or "writing" to a magnetic stripe such five bit
characters, a circuit can be arranged as in FIG. 6. A single wire
64 is formed into a pattern of right angles forming a particular
spatial pattern. Although the wire 64 is drawn away from the stripe
of magnetic material 61 for clarity in the figure, the dotted lines
indicate that when in close proximity the wire and magnetic
material have corresponding areas. The arrows indicate the
direction of magnetization if the wire is laid on top of the stripe
as drawn with current from the left. The dotted lines separate the
stripe into "bit bins" where each bin contains one bit of data.
There are five bit bins shown in the figure. A data bit
corresponding to a "1" is recorded by having a change in the
direction of magnetization within the bit bin. The direction of
magnetization always changes between bit bins. This convention is
well known in the art but is restated here to reinforce the
relationship between the pattern and the transducer 3 (64 in this
example) which is new. The bit bins indicated by 63 contain
therefore data "0"'s and the bit bins indicated by 65 contain data
"1"'s. The spatial pattern of the wire in FIG. 6 is effective for
writing a character "1001" having a parity bit of "1" to a magnetic
stripe. Of course, magnetic stripes on transaction cards may
contain many characters and the structure illustrated is extendible
to a plurality of characters as appropriate for the occasion of
interest.
[0032] For illustrations of the best contemplated transducer, a
simple single strand wire was shown. The reader will appreciate
that other forms of transducers may be useful for providing a
spatially varying magnetic fields and thereby serve to "write" data
to a magnetic stripe. Coils of wires, multiple current carrying
conductors together, printed circuits, et cetera all may serve the
task without deviating from the objective which is to convert
electrical energy into magnetic energy in a spatially distributed
manner. Since the ISO standards for transaction cards can require a
bit density of up to 210 bits per inch, the conductors which
produce useful magnetic patterns are necessarily small. Their size
is compatible with printed circuit technologies. Thus to form
appropriate transducers, methods of printed circuits and other
lithographic techniques are completely anticipated.
[0033] In addition to the primary elements mentioned above,
secondary elements include: a data store 75, comparator 76, enable
pulse generator 77, disable pulse generator 78. These elements are
usually just additional functions of the microprocessor and the
general case above having a "microprocessor" is considered to
include these secondary elements. FIG. 7 shows a block diagram of a
transaction card 71 having all of the elements within the card as
it is with the actual mechanical device. A keypad 72 is available
for user inputs and is in communication 73 electronically with the
microprocessor 74. Tactile input from a user is converted to an
electronic pulse or pulses and transmitted to the microprocessor. A
data store 75 within the microprocessor has a predetermined code
stored therein. The data store is connected to the comparator such
that the code can be recalled and transmitted thereto. This code
has similar function to the PIN used for ATM cards. The code is
compared to the user input to detect coincidence between them in a
comparator 76. If the comparator detects that the user input code
has been properly entered, then it activates an enable pulse
generator 77. Alternatively, if the code is not correctly entered
the comparator responds by activating the disable pulse generator
78. The pulse generators are operable for taking an activate signal
from the comparator and generating an electrical pulse compatible
with the function, enable or disable, at hand. In the case of
enablement, the pulse is usually a square wave pulse of a magnitude
large enough to magnetize the magnetic stripe and is of a duration
compatible with the clock cycle of the microprocessor and circuit
constraints like resistance, capacitance and inductance of the
device. In the case of disablement, the pulse is a sinusoid having
a decreasing magnitude. Both of the pulse generators are connected
electrically to the transducer 3. The transducer in close proximity
to the magnetic stripe 7 and therefore in magnetic communication 79
therewith.
[0034] With the above mentioned hardware in place, the card is
operable for executing the following method. The system performs
the following steps: receives input; recalls data; compares input
and data; generates either an enabling pulse and enters a wait
state, or a disable pulse; then disables the data on the stripe and
returns to the receive input step.
[0035] The card is generally in a disabled state. By "disabled" it
is meant that any data on the magnetic stripe has been erased
rendering the card temporarily useless. A disabled card cannot be
read by card readers . The card remains in this state but awaits a
user input. A user input at a keypad is then converted into an
electric signal and transmitted to the microprocessor. Upon receipt
of user input the microprocessor recalls from a data store a
previously recorded code. A comparator receives both the user input
and the recalled code and attempts to detect a coincidence. If a
coincidence is detected, then the comparator activates an enable
pulse generator. If a coincidence is not detected, then the
computer either activates a disable pulse or allows the card to
remain disabled and returns to the first step. If the enable pulse
is activated, then a square wave electrical pulse is generated and
transmitted to the transducer. The current passing through the
transducer causes magnetic fields in a predetermined spatial
distribution to magnetize the magnetic stripe. The magnetic stripe
then is operable for stimulating a card reader in the known manner.
After a period of time sufficient for swiping the card through a
card reader, between about 30 seconds and 5 minutes, the stripe is
disabled again by activation of the disable pulse generator. The
disable pulse generator produces a sinusoidal signal of decreasing
amplitude. This pulse can be transmitted to the transducer thereby
demagnetizing or erasing the data on the stripe. The card is reset
into a disabled state and again awaits user input.
[0036] In addition, methods of the invention are supported by the
following secondary steps where an issuing institution: prepares a
card with an appropriate transducer, writes data to a data store,
issues card to a user. Preparation of an appropriate transducer
includes arranging the pattern of the transducer to represent a
desired data stream having characters specific to an account or
other identifying object. A card is also provided with a data store
which can be programmed. A reference code or number is recorded
into the data store by an issuing institution. This is the number
that is recalled in the steps described above. The card having been
prepared in this way can be issued to a user. Security is realized
because the code is stored in a highly tamper resistant way. A user
receives the card and instructions regarding the stored code (is
told the code). Cards found or stolen by unauthorized users would
not be able to be activated without knowledge of the code.
[0037] In accordance with each of the preferred embodiments of the
invention, there is provided an apparatus for and method of
providing a transaction card having a means of authentication. It
will be appreciated that each of the embodiments described include
both an apparatus and method and that the apparatus and method of
one preferred embodiment may be different than the apparatus and
method of another embodiment.
[0038] Although the present invention has been described in
considerable detail with reference to certain preferred versions
thereof, other versions are possible. Therefore, the spirit and
scope of the appended claims should not be limited to the
description of the preferred versions contained herein.
* * * * *