WO1998047093A1

WO1998047093A1 - Smart card device and method

Info

Publication number: WO1998047093A1
Application number: PCT/IL1998/000169
Authority: WO
Inventors: Marc Zuta
Original assignee: Marc Zuta
Priority date: 1997-04-15
Filing date: 1998-04-08
Publication date: 1998-10-22
Also published as: IL120675A0; AU6850698A

Abstract

A noncontact card interface (7) comprises means for performing noncontact link with a magnetic card reader (Fig. 1) using a magnetic field to couple with a magnetic head (Fig. 2) in the reader, connected to means for performing noncontact link with a card (24). Signals received from the card are converted to electrical signals, which are converted to magnetic fields to be coupled into the magnetic reader. In a noncontact link between a card and a card reader, a secure link uses physical protection means comprising noise source means to mask the signals between the card and the reader. A method of payment with smart card includes the following steps: a) a vendor computes the total bill; b) total bill is sent to interface means; c) total bill amount is sent to smart card; d) total bill amount is displayed on smart card; e) if user agrees to pay the bill, then he/she performs a manual operation indicative thereof; f) if user agreed to pay the bill, then means in smart card send an identification number stored therein to the interface, to be transferred to the card reader; g) if user does not agree within predefined time, then a time-out means is activated, to clear the received request.

Description

Smart Card Device and Method

Technical Field

This invention concerns noncontact cards and more particularly such devices which include means for noncontact link with a card reader with secure means, and to methods for their operation.

Background Art

At present, various approaches are used to implement a noncontact card (for example a smart card), that is a card including user's identification characteristics, to be used as replacement for cash or the plastic card with the magnetic stripe.

Although the smart card in plastic sheet is being tested and evaluated for more than 20 years, it has not gained general acceptance as a replacement for the plastic card. As early as 1974, Moreno tested plastic cards with electronics therein.

The plastic card itself, although it is used for more than 40 years, has not gained the status of the preferred payment method with users. For example, an U.S. Federal Reserve Report says that only 13% of consumer expenditures used credit cards in 1992. There appears to be a need, which has not been fully answered with prior art devices. It seems that the plastic card is prone to failure. It can become damaged and unusable, for example from heat or magnetic fields, without the user being aware of that. The user may be surprised to find that the card is not honored. Moreover, it is difficult for the user to keep track of expenditures, since there is no user hard copy attached thereto, like in checks.

If the card is lost, then a nonhonest finder can use it, until the cardholder finds this out and cancels the card. The plastic card is easy to read and misuse. The card issuers incur losses in the milliard dollars range per year. These appear to be part of the disadvantages of plastic cards.

Prior art smart cards use electronic components in plastic sheets shaped like ordinary plastic cards. These smart cards are expensive, thus it is more difficult to disseminate to users on a large scale. Moreover, there is installed now a huge infrastructure of magnetic card readers in various stores and merchant's facilities. The smart cards in plastic are not compatible with these readers, but use ohmic contacts on the side of the card. To replace the readers is a huge expense, which may not be justified by the added benefits of these smart cards. It is reasonable to expect a gradual transition from plastic cards to smart cards. This would require two card readers in each store, a costly and cumbersome solution.

Smart cards which generate magnetic fields are compatible with magnetic readers, however these cards are expensive because of their complex structure and are fragile. It is difficult, for example, to keep a smart card in a trousers pocket like the plastic cards. These cards do not include a display to provide financial information to user.

There is a basic incompatibility between smart cards and the present infrastructure for magnetic cards: Systems now in use are devised to implement one-way communications with the card, that is to read the code in the card. Smart cards, however, require a bidirectional link, to allow inquiry of the card and the card response. This would require a drastic change in presently used transaction authorization hardware and software. If the change is done, then the system would be incompatible with the plastic cards. Moreover, this would increase the workload on the authorization centers, an undesired situation.

In my previous invention, as detailed in Israeli Patent No. 096764 and US Patent No 5,241 ,161 , was disclosed a smart card in wristwatch which has electronic means inside a wristwatch to store the user identification code and to send it to a card reader, this intended to replace the magnetic card and the smart card in the plastic sheet.

Although this answers the needs for low cost and ease of use, the card has no means specifically devised for optimal coupling of magnetic fields into existing magnetic card readers.

Another problem with noncontact smart cards is the vulnerability of the link between card and reader. This is a disadvantage of electro-optical links, and more so for radio links used in other cards. The radio waves, because of their good propagation properties, can be received from a distance. Thus an eavesdropper can monitor the dialog between card and reader, to compromise the identity code and possibly misuse it.

It was claimed in prior art that a low transmitted power will achieve a limited acquisition space, however this is questionable. Actually, the power cannot be too low, since then the reader and card will not receive the required power, or the signal to noise ratio will be too low for reliable operation, since the communications will have a high bit error rate.

Commercial cards and readers for widespread use of necessity have a lower cost structure, which achieves lower sensitivity than professional equipment. The small size of the antennas result in low gain, which is compensated by transmitting at higher power.

A professional, very sensitive receiver and a high gain antenna can achieve monitoring from a considerable distance. Moreover, because of the moderate rate of decrease of power with range, there is no drastic decrease of power with range. Thus, the power decreases as the square of distance, and received voltage is proportional to the reciprocal of range. A 10 times increase in range will result in only a 10 times decrease in received voltage. This can be easily compensated for by better sensitivity in the eavesdropper receiver or higher gain antenna.

A solution used in prior art is encryption of the link with the reader. Safe encryption, however, requires a sizable computation effort. Cards with these encryption means demand a higher cost. The computation for encryption also requires a considerable amount of electrical power, thus depleting the battery faster. If power for the card is provided from reader, it requires electrical contacts which are exposed to damage in real life use. If power to the card is provided through electro/magnetic fields or waves, there is a radiation danger to users. Moreover, there are people who are more sensitive to radiation, for example people with implanted pacers.

Another disadvantage of encryption is that there is no guaranteed, or provable, protection. There are optimistic estimates of the time to break a code, however these are based on a "brute force" approach. If there is the incentive (and there indeed appears to be an incentive) , it is believed that a considerable effort will be made to break these codes. More so if the messages are readily acquired, to form the basis for that effort. Apparently it is easier to succeed at decryption when more messages are available.

If that happens, then the contemplated investment in large scale dissemination of the prior art smart cards and the related infrastructure, will be a waste and a disaster.

Another problem with prior art smart cards is that the user has less control over his/her money. Cash money is given in an elaborate manual act, involving the customer's counting and handling over the bank notes. Similarly, a check has to be written and signed.

Money in a noncontact card, however, can be taken away through an automatic response to an inquiry from a reader. A fraudulent inquiry, from some device impersonating a card reader, can take "electronic money" from people who cannot prevent it and may be even unaware of it. Since the "electronic money" is actually real money, the user should be provided with adequate means to control its delivery.

There is also the possibility that, in a legitimate transaction at a supermarket or a toll road, the card reader will connect to the wireless card not of the customer now being served, but to the card of someone else nearby. That person then pays someone else's bill. No one can see the waves of the noncontact link, thus it is difficult to monitor or control the invisible, electronic money flowing in the air.

The weak link in smart card transaction is the noncontact link between card and card reader. The subsequent data transfers are easier to protect.

It is an objective of the present invention to provide for a noncontact card with means for overcoming the abovedetailed disadvantages.

Disclosure of Invention

It is an object of the present invention to provide a noncontact card using a noncontact link with a magnetic reader, and including security means. The noncontact channel achieves higher reliability of the card.

This object is achieve by a noncontact card as disclosed in claim 1. In accordance with the invention, the object is basically accomplished with interface means which allow a smart card to communicate with presently used magnetic card readers. This presents an economical systems solution, allowing to use low cost smart cards with existing readers infrastructure. The interface means, although higher cost than the cards, are required in smaller quantities, since there are less card readers than cards.

According to a second object of the present invention, the noncontact card interface includes a controller, with means for performing a bidirectional dialog with the card, then to transfer result to reader. This allows to use smart cards which require bidirectional dialog with a reader, within an existing infrastructure in which the link with the card reader is unidirectional.

According to another object of the present invention, the noncontact card interface is independent, using its built-in power source (solar cell), so that no electrical connections are required with a card reader. The interface snaps on the magnetic reader, for easy installation and removal.

According to a another object of the present invention, the card includes a secure link with the card reader, using physical protection means. Noise sources are used to mask the signals between card and card reader.

According to still another object of the invention, the secure link is installed on a computer or a computer terminal to create a secure zone near the computer. A user can send a sensitive credit card code to a reader located within the secure zone. This protects the communication between a card and a card reader, which is the weak link in smart card transactions.

According to another object of the invention, the noncontact card includes means to allow the user to control the transmission of the identification code, conditional upon user's agreement to the contemplated transaction. "Electronic money" cannot be extracted from the card against the user's will or without his/her a priori approval.

The above interface means and secure link may be used for any type of noncontact channel between a card and a card reader, and for both smart cards and "dumb" cards, that is cards with no intelligence or RAM memory but which only hold a user-related data string like the plastic card.

Further objects, advantages and other features of the present invention will become obvious to those skilled in the art upon reading the disclosure set forth hereinafter.

Brief Description of Drawings

The invention will now be described by way of example and with reference to the accompanying drawings in which:

Fig. 1 illustrates a smart card and noncontact interface, using a simplified block diagram. Fig. 2 details a magnetic interface/coupler with card reader, including a solenoid shaped as a plastic card it replaces.

Fig. 3 details a magnetic interface, as an addition to head in reader.

Fig. 4 details a magnetic interface, as an addition to slot in reader.

Fig. 5 details the structure of a magnetic interface/coupler.

Fig. 6 illustrates a secure link with a card reader.

Fig. 7 details a personal computer with a secure link.

Fig. 8 illustrates a secure noncontact links for a computer, with Fig. 8(A) detailing transmitters attached to a computer and Fig. 8(B) detailing transmitters attached to a keyboard.

Modes for Carrying out the Invention

A preferred embodiment of the present invention will now be described by way of example and with reference to the accompanying drawings.

Interface with smart card

Fig. 1 illustrates, in a simplified block diagram, a smart card 5 and noncontact interface means to a magnetic card reader 1 . A card reader 1 may be connected to a computer, telephone or cash register (not shown). This achieves an interface between smart card with noncontact channel and a presently used magnetic card reader. It allows use of both smart cards and plastic cards, with the same reader.

Rational 1 : Magnetic card readers are widespread, are available everywhere and connected to computer centers. This large infrastructure cannot be ignored or wasted, but should be used by the smart cards.

A smart card with magnetic field output is expensive. A card in plastic, with protrusion to magnetic slot, is not easy to use, and difficult to integrate in wristwatch. It is difficult to use, to bring watch into slot in magnetic reader. Magnetic coupler in watch is not easy to produce, and is not comfortable- large protrusion. It is not low cost- all watches have to include it. It is fragile, not fit for everyday use.

Rational 2: Smart cards at present cannot use the magnetic reader. Electro-Optical (EO) card is easier to produce, low cost, small, consumes low current, is very reliable. For example my patent for smart card in wristwatch, with its preferred embodiment using an EO link to achieve low cost and high reliability, and small size- suitable to integrate in watch. Other smart cards use ohmic contacts (the IC in plastic approach), or wireless (using RF waves), like the identification device in vehicle now being tested for toil roads for example. There are so much more smart cards than magnetic readers - each store with a magnetic reader serves thousands of users. It is cheaper and easier, overall, to invest in improving the card reader, to adapt to existing smart cards or to economical and practical planned cards.

Thus, an interface to magnetic readers is provided, to match between noncontact smart cards and existing magnetic readers. The smart cards may be low cost electro-optical or with radio waves RF for example.

Rational 3: It is predicted that smart cards will enter gradually, and for a long time there will be dual use of both smart cards and dumb cards (plastic cards with a magnetic stripe). Therefore it is desirable that readers be capable of reading both types of cards.

The interface means include inductive coupler 2 with reader 1 , using a magnetic field link 21 . The mechanical coupling with reader 22 is used to attach coupler 2 to reader 1 for good, reliable coupling therebetween. Several embodiments for the inductive coupler 2 are detailed below.

Coupler means 4 communicates with smart card 5 through a noncontact link 45. The noncontact link 45 may comprise light waves or infrared or radio waves (RF). Interface electronics 31 include means for conditioning the electrical signals received through noncontact coupler means 4. These may include amplification, to achieve a stronger signal in reader 1 , and filtering, to eliminate harmonics and noise. For electro-optical sensors, filter means to attenuate the 50 Hz or 60 Hz noise (and their harmonics) from fluorescent lights may be required.

In a minimal embodiment, interface electronics 31 may be disposed with, or may include only passive filter means, by using coupler 4 which generates electrical energy at a level high enough to couple directly to reader 1. Effective coupling means 2 to reader 1 are necessary as well, like a coil with a multitude of turns, and making good magnetic flux coupling into the head in the magnetic reader. In this embodiment, there is no need for electrical sources, thus energy source 33 can be eliminated as well.

Means to enter the billing amount, like keyboard 32 or a numeric keypad or alphanumeric or pushbutton may be required to enter manually the total amount to be sent to card 5, in case the interface is coupled to an existing reader 1. Presently used readers can only read from card, and do not include means to transmit the total charge to card. By using numerical entry means 32 to enter manually the charge amount, with a link to transmitter in coupler 4, that information is sent to card 5 to be displayed to user on display means 51 .

The user can be sure as to the exact amount his/her card will be charged. In addition, that information is stored in the card, to display later, together with other financial information like the account balance.

Electronics means 31 may include (not shown) means to also send to card 5 information relating to time and date of transaction, as well as store identification. This data will be stored in memory means (not shown) in card 5 and displayed later to user. This is achieved just with the addition of the interface means, without any change in the card reader 1 itself.

Independent operation of the interface means

In a preferred embodiment, solar cell means 33 generate the electrical power required to operate the interface, without any physical contacts to reader 1 or any source of energy. There is no need for battery or periodic battery replacement.

This achieves long life of the device, with low cost maintenance. This structure is especially useful for a very large quantity of interface units, to be attached to the multitude of card readers now in use. It does not need electrical connection to the card reader or electricity source or power supplies.

An independent interface is thus achieved, with its own power source. It attaches easily to reader 1 , with mechanical coupling means, that is it snaps on one magnetic reader. It is also easy to install and remove, allowing fast switching to either noncontact cards or simple plastic cards.

Adapt various smart cards to existing infrastructure

Coupler 4 maintains a noncontact link 45 with smart card 5. The type of link is adapted to the smart card in use. For an electro-optical card, the link is with light rays, either visible light or infrared or ultraviolet. Invisible light is preferred, since it allows to conceal the card, for better protection. A minimal card includes only a transmitter, thus coupler 4 includes only a photodetector. An advanced card also includes receiver means, to accept an interrogation code as well as information relating to the present transaction, as detailed above.

In this case, coupler 4 also includes a transmitter (not shown), for example a Light Emitting Diode LED or laser or other means.

For a wireless card, coupler 4 includes antenna means to receive RF waves, and optional receiver and transmitter circuits as known in the art.

For a card with ultrasonic waves, a corresponding interface is used. For a smart card in plastic with ohmic contacts as known in the art, coupler 4 includes (not shown) electrical contacts to connect to the smart card. Thus, even those cards can be connected to the existing plastic cards infrastructure. Electronics means 31 then includes means to supply electrical energy to card 5 and to conduct a bidirectional communication according to a predefined protocol.

Thus, the smart card interface means allows operation with presently used magnetic card readers. This presents an economical systems solution, allowing to use low cost smart cards 5 with existing readers 1 and their infrastructure. The interface means, although higher cost than the cards, are required in much less quantities, since there are much less card readers than cards. Thus the overall cost is much lower than with complex smart cards, to present a more practical solution.

Transmit ID only after user's approval

Noncontact cards like a smart card 5 will include control means 52, to allow a conditional transmission of an Identification Code ID. That is, the user has to agree to a transaction, and only then the smart card will identify the payer and will send an ID (or a code to indicate agreement to transaction). That is, the "code for approval of transaction and user identification" is sent to reader only after a predefined manual act of approval is done by user with the smart card.

Rational 1 : a user does not want his/her money to sneak away, or to be "pulled out" by any external noncontact device or card reader. The ID/agreement code represents real money, thus its transmission should be protected.

An operation by user is necessary, the equivalent of the act of giving money bank notes (the physical form of money) or signing a check, or handling over the plastic card to the seller to be used there.

Rational 2: some people feel that an ID in card does not offer enough protection, therefore require an additional protection using PIN (Personal Identification Number) to be memorized by user and entered to approve transaction. This is implemented by means in card, to send ID only after receiving that PIN from user. A Simple Method:

10. transaction is defined at store, amount due is computed and displayed, to clerk and customer

20. customer, if he/she agrees to pay the amount due, they perform a manual operation on the smart card, to indicate agreement to the transaction

30. smart card transmits ID stored therein to reader, upon receiving the manual operation indicating the user's agreement to do so.

Method of payment with user's agreement (detailed):

10. compute sum to pay, total bill

20. vendor sends or enters total to interface means. May be implemented with link from cash machine (automatic) or keypad, manual entry

30. send total to card, with time, date, transaction no., store ID

40. smart card display on card, displays tentative transaction, as sent by reader, with transaction number and amount of money due.

50. user, if he/she agrees, does a manual operation, like: * press a button * enter secret code: directly (numeric keypad on card) or press button when the correct number is displayed, out of a sequence of numbers, or enter digit after digit, until all is done, or using special timing

60. if user agrees - card sends ID, code for agreement with transaction number, date etc. to interface. The interface sends user ID and information to magnetic reader. This replaces manual ID entry from magnetic stripe in plastic card. The card reader then sends the information to authorization center and/or cash register, similar to the method used with a pattern or ID read off a plastic card.

Additionally, after user agreement, electronic means in card record the details of the transaction into card's memory. Including date, sum, vendor identification.

70. if user does not agree within predefined time- then at time-out, request canceled from card.

Manual agreement by user, example of means for:

a. pushbutton, which is pressed to agree

b. keypad, numeric or alphanumeric, user enters PIN or password

c. pushbutton used in conjunction with display of changing numbers or letters or words or shapes. The user activates pushbutton in response to what is displayed, based on secret information on their memory, to identify themselves and approve transaction

d. pushbutton pressed at a certain rate or rhythm, known in secret by user

Method for device: interface

10. receives transaction details, composes message with time, date, transaction number.

20. transmits details to card

30. receives ID, approval details

40. transmits approval, ID to reader, like plastic ID in mag-stripe

Method for device: smart card

10. keep memory with ID code

20. input channel for receiving interrogation and information relating to present transaction and to display to user, transfer to control means 30. display means for displaying to user the information on transaction 40. input means for manual agreement by user to the transaction 50. control means- waits for user manual agreement . after agreement - transfer ID to output channel to reader or interface thereto. 60. if agreed to transaction - keep in memory, update financial records.

If not agreed, then at time-out, erase/cancel request and information for agreement from reader/interface

Interface including a controller for bidirectional dialog with card

In another embodiment of the invention, controller means is included in electronics 31 and transmit/receive coupler means 4 (not shown) in the interface, which allows for improved performance as detailed below.

A. send information to card 5, like sum of billing, transaction number, store ID and time/date. Transaction number is an ad hoc number generated by the interface to identify the present transaction. Card 5 responds with its ID and repeating the transaction number, to indicate the transaction to which the user agrees to pay.

B. Load new cash to debit card, extend term of credit card through same noncontact link. This is an easy method, device to update card. Means are included in card to protect from misuse, unauthorized loading of data, i.e. with encryption or special means.

Use: customer pays at cash register for new money into card, then the new electronic cash is loaded in card. C Load new cash as change from previous payment, like return for prepayment to telephone call which was not fully used. Achieve a goal similar to that of prior art telephone cards which remain stuck in reader until end of transaction.

New device, method: load credits from card to telephone reader at start of connection; use pay telephone, up to the maximum credit allowed; at end of call, couple card again to reader, to accept change back, or remaining credits.

Benefits: Noncontact- very reliable and easy to use. Display on user's card shows remaining credits, can be verified (users now do not always trust the system, but cannot check it ).

D. Controller in interface manages counting of credit (tokens) used, i.e. for telephone calls use. Receives from card maximum credit stored therein. It later returns change, using controller in interface.

New device, method for interface:

10. load credits from card to telephone reader/interface at start of connection;

20. use pay telephone, up to the maximum credit allowed;

30. interface receives from telephone the signals indicative of tokens used, and subtract from maximum; 40. if maximum tokens used, then warn user and disconnect telephone; 50. at end of call, couple card again to reader, to accept change back, or remaining credits.

Benefits:

Usable with existing telephone infrastructure for toll telephones, which sends to telephone signals to take/deduce tokens or coins as the time passes and more has to be paid.

Noncontact channel is very reliable and easy to use.

Display on user's card shows remaining credits, can be verified (users now don't always trust the system, but cannot check it ).

E. card programming by card issuing agency (VISA, MASTERCARD, CAL, ISRACART.. ) through noncontact link. Uses the same link as usual. Smart card programmer is performed using secure link, maybe encrypted from center, and decoded in interface or card 5 itself.

Interface of smart cards with existing readers and infrastructure

Existing magnetic card readers perform unidirectional dialog with card, whereas smart cards require a bidirectional dialog with card. A simple and efficient solution, using the interface in the present invention, uses magnetic readers in stores which remain the same, communication with center unchanged, and center remains the same.

An interface means is added between the smart card and magnetic reader, where:

- communication with magnetic reader is unidirectional (to reader), but communication with card is bidirectional.

- interface accepts ID from card in an encrypted form, like DES or RSA, using a bidirectional link with card, like interrogation/answer protocol

- interface transmits ID from card or a message derived therefrom to reader

-center receives message from interface through reader, decrypts it if the message was encrypted, and decides whether ID is for a valid card. If positive, center then authorizes the transaction.

The solution, more detailed:

- the interface includes random or pseudo-random numbers generator, generates inquiry string to card with that number. A simple, low cost device can generate these numbers, for example a counter counting a fast clock and read at random. - card answers with that pseudo-random number and its ID code, all encrypted by DES or RSA or other method, or other encryption operation involving the inquiry string and the ID in card.

- interface receives answer from card, transmits all to reader, together with the initial inquiry string (optional, to prevent sending same code over and over, which may be copied from somewhere)

-center receives all, decrypts, decides whether ID and inquiry are compatible, and then authorizes the transaction.

Rational: interrogation code is most easy to produce, at low cost, in the interface device. This saves additional load from center, and time of communications.

Interface is simple and low cost- it is easy to generate random numbers, with minimal hardware- like counter with asynchronous read and bits juxtaposition or interchange ; to verify encryption is more difficult and costly -thus done at center, which has adequate facilities.

Center can accept both encrypted answers and non-encrypted (plaintext) answers, and act accordingly, thus existing centers and infrastructure are compatible with both smart cards and simple cards.

Advantages: use same magnetic reader, infrastructure. May start smart card introduction with plaintext, and later to convert to ciphered messages. Interface can support both, only software in center has to be updated. A system implementation can start with simple encryption, like DES. It is possible to convert to a more secure encryption method like RSA at a later time. The conversion can be performed at a minimal expense, requiring only an updated software in card centers and the smart cards. The interface may remain the same. The same interface may transfer both plaintext and encrypted messages.

Thus, the abovedetailed interface is good for present and for the future, allows both low cost entry into this new technology and low cost later updates.

Flexible operation, expandable in future.

According to another aspect of the present invention, the controller includes means to achieve a dual mode interface (implemented with IC in interface). The mode can be selected in hardware, for example using a switch or jumper or other means. Thus, the interface operates either with or without encryption.

Method of operation:

1. Plastic card emulation mode: read ID from smart card, transmit "as is" to magnetic reader. Usable for low cost smart cards, with transmit only, to send ID from card on button pushed, similar to plastic cards, but code is better protected with inclusion in watch, manual approval (E) and link protection (D). Thus better performance, security than with plastic cards is achieved, while it is fully compatible with magnetic reader and infrastructure. Low cost, requires only transmitter in card. This is best for present or fiist stage, for easy transition to smart cards.

2. Smart card advanced mode: with encryption, dialog with card, can be activated later, after (1) is successfully installed and operational, and if need arises, may use simple encryption for low cost, low power consumption in card.

3. Smart card with complex encryption: in future, when that encryption will be performed at low cost and low power consumption, then it can be introduced, still using the same interface means.

Thus, the interface means is a good investment and a practical solution, allowing to easily start smart card introduction on a large scale, and later to upgrade performance if and when necessary and practical.

Problem: encrypted card requires bidirectional communications, but present magnetic reader is unidirectional. Infrastructure with card center is unidirectional code reading as well. Requiring the center to interrogate each card in each store would create big load on center.

During the transitional stage to smart cards use, which may take long time, readers should accept both plaintext, non-encrypted plastic cards and new encrypted smart cards. This may continue forever, since plastic cards are widely used and may not be discontinued. It may be possible that in the future, for high amounts of money the encryption will be required, and for small amounts- plaintext is good enough.

Solution: use smart interface with dual mode of operation as detailed above, to operate both with prior art plastic card and the smart cards; both at the card reader level (to communicate with card) and at the system level (communicate with the transaction authorization centers).

The above interface means may be used for any type of noncontact channel between a card and a card reader, for example using an electro-optical EO link or radio wireless RF link or ultrasonic link.

The interface can be used for both smart cards and "dumb" cards, that is cards with no intelligence or RAM memory but which only hold a user-related data string like the plastic card.

It may be advantageous for a user to use a cards carrier device (not shown) which holds a plurality of cards, both smart cards and "dumb" cards to emulate existing plastic cards. The user may choose to activate any of these cards according to circumstances, for example a discount card for a specific store to pay there, or a telephone card to use a public telephone.

In any case, a reliable and easy to use noncontact channel may be used with a card reader, as detailed above. Interface with existing magnetic card readers

Fig. 2 details a magnetic interface/coupler with card reader, using a solenoid shaped as the plastic card it replaces. The advantage of this embodiment is that the interface can be inserted to allow operation of smart card, or removed to allow operation with prior art plastic card, all using the same magnetic reader, to be found in practically every store.

Fig. 2(A) illustrates one embodiment of the coupler, and its coupling to the magnetic head 13 in card reader 1.

The inductive coupler with reader 1 includes coil means 23 to generate magnetic field link with card reader 1 , made of wire wound around base sheet 24. Base 24 may be made of plastic, for example. The mechanical coupling with reader 1 includes the base sheet 24 shaped as a plastic card, of about 0.7 - 0.9 mm width, to be held in the channel 12 of card reader 1 , between magnetic head 13 and the wall opposite 14.

Head 13 is usually attached to reader 1 through elastic means (not shown) to keep it pressed against the wall opposite 14 while there is no card, or to the card if present. It thus holds sheet 24 in place, with coil 23 generating magnetic field which is coupled into magnetic slit 133 in head 13. Coil 23 may have dimensions of about 1 x 1 cm to 2 x 2 cm or more. Wide area of coil 23 ensures that some part of it will come into contact with slit 133, without the need to precisely align them against each other. This provides for ease of use, and reliable coupling. Otherwise it may be difficult to couple to the small slit 133, to effectively induce the magnetic field from coil 23 in the slit 133.

The ends 233 of coil 23 are connected to electronics (not shown) in the interface, which generates the electrical current required to create the desired magnetic field in coil 23.

Fig. 2(B) illustrates another embodiment of the coupler.

Here, coil means 23 to generate magnetic field link with card reader, made of wires 231 carrying current in one direction adjacent to each other and attached to base sheet 24, with return wires 232 attached on the same side of sheet 24, and separated from wires 231. The separation of wires 232 is required so that their field (not shown) in the opposite direction will not cancel the field of wires 231.

Wires 231 result in an about laminar magnetic field (not shown) normal to the direction of the current and parallel to the surface of sheet 24, so as to couple magnetic field into the slit in the magnetic head of the reader (not shown). A plurality of wires is desired to create a stronger field, for the same current, thus to make more efficient use of electrical current.

The side of sheet 24 which has the wires 231 attached thereto is brought close to a head in magnetic reader (not shown) to couple magnetic field thereto. Fig. 3 details another embodiment of the magnetic interface/coupler, as an addition to the magnetic reader (to head). This embodiment allows for fixed attachment of interface to existing readers, to allow reading of both smart cards (through smart card interface and generated fields as detailed below) and prior art plastic cards (cards are simply inserted in reader and read as usual, without the addition to interfere with that process).

Figs. 3(A) and 3(B) illustrate two embodiments of this device. Referring to Fig. 3(A), coil means 23 which are used to generate the magnetic field to link with card reader (not shown), is attached directly to the magnetic head 13. The wires 231 carrying current in one direction, adjacent to each other, are attached to be close to magnetic slit 133 in head 13. The return wires 232 are attached to head 13, further away from slit 133, so that their field in the opposite direction will not cancel the field of wires 231 . Optional coating (not shown) with a hard protection means, like plastic or nonferromagnetic coating.

Advantage: good coupling into magnetic head 13, since wires close to slit 133. Disadvantage: careful attention should be paid, lest it interferes with plastic card reading. Wires 231 are subject to mechanical wear from use of plastic cards.

This embodiment has some reduction in plastic card efficiency because of the gap thus created.

Preferably this embodiment includes means to minimize the interference with operation of plastic cards, while wires attached to head: 1 . Wires are made, for example, of copper Cu, or aluminum Al, do not interfere with magnetic fields. Thus if wires are thin, then the additional layer is thin as well, and plastic card can be used, without the wires interfering with the field coupling to reader. There will be small interference because of the small separation card- reader, but minimal.

2. High impedance driver circuit to the wires. Another source of interference is induced current in those wires, which creates a magnetic field opposing the original field from card. The mechanism includes the stages of: Movement of card with respect to head creates an alternating magnetic field; the changing field induces a voltage in the interface wires; the voltage results in a current in the circuit; the current creates a magnetic field, opposing the field of the card; the difference between the original field and the opposing field is coupled into the magnetic head in the reader. Thus, the field in the reader is reduced.

To prevent this field reduction, a high impedance circuit is used in wire coupler means. Thus, the induced voltage will generate a minimal, practically zero current, which results in negligible opposing field.

Implementation: use a current source, like the collector of a transistor, or voltages applied through diodes or other unidirectional means, which are active (conducting) only when coupled with a smart card, when a plastic card is unlikely to be used. Fig. 3(B) details another embodiment, wherein coil means 23 which are used to generate magnetic field link with card reader, are attached directly to the magnetic head 13.

In this embodiment, wires 231 carrying current in one direction, adjacent to each other, are located some distance from magnetic slit 133 in head 13 so as not to prevent contact of slit 133 with a plastic card 17. The return wires 232 are attached to head 13, further away from slit 133, so that their field in the opposite direction will not cancel the field of wires 231.

Advantages:

There is no interference with plastic card reading.

Wires 231 are protected from wear from use of plastic cards.

Has no effect or influence on plastic card reading efficiency.

Disadvantage:

Lower efficiency of coupling into magnetic head 13, since wires are not so close to slit 133. More current is required, or more wires in coil 23.

Fig. 4 details another embodiment of the coupler to reader with coil means attached to the wall opposite the magnetic head. This is a fixed addition to the magnetic reader, which does not interfere with normal reading of prior art plastic cards and protects the new coil from wear from plastic cards sliding in the reader's slot. Fig. 4(A) details the device without a plastic card inside. A magnetic interface/coupler includes the addition of coil 23 to card reader, attached to wall opposite 14 the magnetic head 13 in card reader 1. Coil means 23 used to generate magnetic field link with card reader, include wires 231 carrying current in one direction, adjacent to each other, and mounted in a recess 144 in wall opposite 14 the head 13.

Return wires 232 are mounted in recess 144, some distance from head 13, so that their field in the opposite direction will not cancel the field of wires 231 .

An elastic mount (not shown) of head 13 pushes the head out, and presses it against opposite wall 14, so that slit 133 is brought close to wires 231 which create the magnetic field coupled into head 13. Thus a good coupling is achieved, with repeatable, reliable performance.

Advantages: good contact or coupling with the magnetic head, while it is not interfering with plastic cards. The interface is separated from the magnetic stripe and magnetic field in plastic card.

Fig. 4(B) details the device with a plastic card 17 inside. The elastic mount (not shown) of head 13 pushes the head into contact with the plastic card 17, to read the magnetic stripe (not shown) thereon. The wires 231 and 232 of coil 23 are protected from the card 17, being located in a recess 144.

Fig. 5 details the physical structure of magnetic interface/coupler.

The inductive coupler 2 with reader may be implemented as detailed in Fig. 2, to include a coil (not shown), and with a protective coating like plastic. The interface electronics 31 may be contained in a protective box. The solar cell means 33 are attached to the device, for generating the required electrical power. Means 33 are preferably attached to the upper part of the device, to better receive light from illumination means in the store.

The non contact coupler with card (not shown) may include electro-optical transmitter or LED 41 and electro-optical receiver or photodetector 42. Thus, a card (not shown) brought close to the device interacts with the transmitter 41 and receiver 42. Other noncontact means may be used, for example radio waves, with suitable transmitter 41 and receiver 42. For RF waves, means 41 and 42 comprise antennas for electromagnetic waves.

The interface can snap-on on card reader (not shown), with coil in coupler 2 coming in contact with reader magnetic head, solar cells 33 convert ambient light to electrical energy which is supplied to the interface to allow its operation, and means 41 , 42 directly interacting with a smart card (not shown). Thus, the interface allows for easy attachment to an existing card reader, without any connections to be made and no changes required in the reader.

To read a plastic card, interface is taken out of the slot in the reader, and the plastic card is inserted instead. Thus, the interface allows the card reader to operate with both smart cards and prior art plastic cards.

Advantages: Simple to use, no connections, no batteries, no change to magnetic reader. Dual operation, with both smart cards and plastic cards.

Secure link with a noncontact card

Fig. 6 details a secure link with card reader, using physical means, in hardware, to protect the link from eavesdropping. Using a secure link achieves a high level of security, even without encryption of the link with the smart card. This allows for low cost cards and low power consumption in the card, without sacrificing security. Alternatively, a lower level of encryption can be used at present, while still achieving good protection.

The physical protection means provide a high level of assurance that the link is secure, since it is unlikely that a small signal will be detectable in noise, where the noise is stronger than the signal and both signal and noise have the same chaiacteristics in the time domain and the spectrum domain, so as to render the signal indistinguishable from noise. The above secure link solve the problem that a noncontact link is subject to eavesdropping. Unless performed in sealed chamber, which is difficult to implement in commerce, the transaction between card and reader is in danger of eavesdropping and subsequent misuse like with impersonification.

For a link using radio waves, it was stated that low transmitted power limits the reception range, but this statement is questionable. Because of wave propagation laws, the received power decreases gradually, and it is impossible to achieve a high power in one zone, with an abrupt power decrease to zero outside that zone. This is possible only by using a metallic sealed chamber, which is usually unfeasible for practical situations in commerce.

Since smart cards and readers use a low cost receiver, which has higher noise related therewith, a relatively high power is required for reliable transmission. An eavesdropper may use professional, high cost and sensitive receivers and high gain antennas to intercept very low power signals. Moreover, there is ambient noise to overcome, which forces a higher power to be transmitted, this helping an eavesdropper.

A solution disclosed in the present invention, includes the creation of a secure area or zone 6, wherein the transaction takes place. The secure zone 6 is created by transmitters 61 of noise in the bandwidth of operation of link, transmitting random bits, in a format similar to the real data. That is, transmitter 61 preferably generates signals having the same pulsewidth, time between pulses and general format as the pulses used in the noncontact link between card and reader. This prevents an eavesdropper from using filtering and/or signal processing means to distinguish between the card/reader signals and the masking noise.

In a preferred embodiment, each transmitter is directional and points to the outside and away from the secure zone 6, using a directional transmit pattern 62. In other words, pattern 62 preferably has a minimum toward the card reader and/or the card.

Anyone outside the secure zone 6 will receive the noise at a high power than that of a signal from card or reader, and will not be able to distinguish the real signal from the noise.

Although zone 6 was illustrated as being of a circular shape (that is, a spherical shape in a tri-dimensional space), this is only a simplified presentation. The size and shape of zone 6 depend on the actual radiation patterns 62 of the transmitters 61 , the radiation patterns of the noncontact card and reader, the relative transmitted power in the card and the noise transmitters, and the degree of security to be achieved. Therefore, throughout the present disclosure it is to be understood that secure zone 6 may have a complex, maybe irregular tri-dimensional shape which is created about the location of a noncontact card reader.

Transmitters of noise 61 may be of any type and use any media: radio frequency RF, ultrasonic US, light (IR, visible, UV), of the same type as the noncontact link 45 used with the smart card 5. The magnetic card reader 1 with noncontact coupler 4 attached thereto, are located in the secure zone 6, with noncontact card 59 being brought close to reader 1 and coupler 4, all within area 6. Noncontact card 59 may be a smart card or a "dumb" card holding a simple code like that in a plastic card. Other type of noncontact reader (not shown) may be used i lieu of the magnetic reader 1 with noncontact coupler 4.

A secure zone 6 is created with a plurality of noise transmitters 61 , each pointing outside and away from area 6, each transmitter having a transmit pattern 62 with a maximum in a direction away from area 6, and a minimum towards coupler 4 in area 6.

The embodiment as illustrated uses four transmitters 61. It is possible to use more transmitters, or less.

A minimal embodiment uses just one transmitter (not shown), with a generally omnidirectional pattern to provide 360 degrees of coverage. This configuration may result in interference in reader 1 , which receives that noise. The interference may be canceled electronically as detailed below. Where a partially closed space is used (for example a space closed in one direction with a wall which may be also an RF shield), then a directional noise transmitter (not shown) may be used, directed toward the open side of the space. The noise transmission is implemented in RF using directional antennas (not shown) pointing away from coupler 4, or with Electro-Optical transmitters for an EO link.

The noise transmitted by transmitters 61 has about the same frequency spectrum as the noncontact link between card 59 and coupler 4, and preferably uses the same type of signals (like pulses or modulated RF) with a noise-like modulation. Thus, the noise masks the signals between the card 59 and coupler 4 to render them indistinguishable from the noise.

This apparatus prevents eavesdropping to the communication with the card 59, and no increase in gain or sensitivity of eavesdropper will do. Increasing the gain will only increase the level of noise, and the signal will still be masked, protected within the noise.

Preferably, each transmitter 61 transmits a noise uncorrelated with the other transmitters, so no elimination by crosscorrelation can be performed by eavesdropper.

In another embodiment, the transmitters 61 have a minimum of patterns 62 towards the location of card 59, if the card is also receiving. This prevents the noise generated in transmitters 61 from interfering with reception in card 59.

The noise received in reader 1 can be eliminated or canceled out by subtracting the noise known to be transmitted, from the receiving signal. A link (not shown) between reader 1 and the transmitters 61 is used to transfer a replica of the transmitted noise to an analog subtraction circuit (not shown). Adaptive correction circuits can be used to correct the gain and phase of the noise signals prior to subtraction, so as to best cancel the received noise.

This cancellation technique can be used without the directional pattern 62 of transmitters 61. Thus, noise is received in reader 1 , and is electronically canceled out to reveal the signal from noncontact card 59.

The above secure link means and method may be used for any type of noncontact channel between a card and a card reader, for example using an electro-optical EO link or radio wireless RF link or ultrasonic link.

Fig. 7 illustrates a personal computer with a secure noncontact link to a smart card. A computer means 7 has display means 71 directed toward a user 8, and keyboard means 72.

Noncontact card reader 73 may be located on computer 7. In another embodiment, a card reader 733 may be located on or inside keyboard 72. A noncontact card 59, like a smart card, is brought close to reader 73 to achieve a secure link, while both card and reader are located within a tri-dimensional secure zone 6.

A secure zone 6 is created with one or several noise transmitters 61 , each pointing outside and away from area 6, each transmitter having a transmit radiation pattern 62 with a maximum in a direction away from zone 6, and a minimum towards reader 73 or 733. In the example as illustrated, three transmitters 61 are used, attached each to one of the back and the lateral sides of computer 7.

For RF transmitters, a microstrip antenna (not shown) may be used to create each one of the radiation patterns 62. Several elements may be used to create a directional pattern in a desired direction, while the antenna is very thin so as not to present an obstruction.

In another embodiment (not shown), a secure zone is created around a laptop computer, with noise transmitters being mounted on the sides of the computer box and/or the display unit.

Fig. 8 illustrates secure noncontact links for a computer.

Fig. 8(A) details transmitters attached to a computer means 7, with display means 71 , keyboard means 72 and a noncontact card reader 73.

A noncontact card (not shown) should be located within a secure zone 6 to achieve a secure link between card and reader.

Secure zone 6 is created with one or several noise transmitters 61 , each pointing outside and away from area 6, each transmitter having a transmit radiation pattern 62 with a maximum in a direction away from area

6, and/or a minimum towards reader 73.

Fig. 8(B) details transmitters attached to a keyboard means 72.

A noncontact card reader 733 may be located on or inside the keyboard 72.

A noncontact card (not shown) should be located within a secure zone 6. Secure zone 6 is created with one or several noise transmitters 61 , each pointing outside and away from area 6, each transmitter having a transmit radiation pattern 62 with a maximum in a direction away from area 6, and/or a minimum towards reader 733.

The abovedetailed interface and secure link can be used for both smart cards and "dumb" cards, that is cards with no intelligence or RAM memory but which only hold a user-related data string like the plastic card.

Various embodiments will occur to people of the art upon reading the above disclosure.

It will be recognized that the foregoing is but one example of an apparatus and method within the scope of the present invention and that various modifications will occur to those skilled in the art upon reading the disclosure set forth hereinbefore.

Claims

ClaimsWhat is claimed is:

1. A noncontact card interface comprising means for performing a noncontact link with a magnetic reader using magnetic field to couple with a magnetic head in the reader, connected to means for performing a noncontact link with a card, wherein signals received from the card are converted to electrical signals, which are converted to magnetic fields to be coupled into the magnetic reader.

2. The noncontact card interface according to claim 1 , further including controller means for performing a bidirectional dialog with the card, and for transferring the result of the dialog to the reader.

3. The noncontact card interface according to claim 1 , further including a secure link using physical protection means comprising noise source means to mask the signals between the card and the reader.

4. The noncontact card interface according to claim 3, wherein the noise from the noise sources have characteristics similar to the signals in the link between the card and the card reader.

5. In a noncontact link between a card and a card reader, a secure link using physical protection means comprising noise source means to mask the signals between the card and the reader.

6. The secure link means according to claim 5, wherein the noise generated in the noise sources has characteristics similar to that of signals in the noncontact link between the card and the card reader.

7. The secure link means according to claim 5, wherein the radiation pattern of each of the noise sources has a minimum towards the card and/or reader.

8. The secure link means according to claim 5, wherein the noise source means are mounted on a computer means to create a secure zone close to the computer.

9. A noncontact card including an identification code stored therein and manual control means, wherein the code is only transmitted to a noncontact card reader upon the activation of the manual control means.

10. The noncontact card according to claim 9, wherein the control means include pusbutton means or alpha-numerical data entry means.

11 . A method of payment with smart cards including the following steps:

A. a vendor computes the total bill;

B. total bill is electronically sent to interface means, or manually entered into interface means; C total bill amount is sent to smart card, together with optional time, date, transaction number and/or store identification;

D. total bill amount is displayed on smart card;

E. if user agrees to pay the bill, then he/she performs a manual operation like pressing a button or entering a secret code;

F. if user agreed to pay the bill, then means in smart card send an identification number stored therein to the interface, to be transferred to the card reader, and the details of the transaction are stored in the memory of the card; and

G. if user does not agree within predefined time, then a time-out means is activated, to clear the request received from the card reader.