MXPA98001882A - Improvement in the security of a card with c - Google Patents

Abstract

A chip card (10), such as a financial transition card, having first identification data written in a portion of read-only memory of circuitry contained in the card (76), where the second and third identification data are respectively encoded in an optically variable device readable by a machine (for example a hologram) and a magnetic strip on the card (66, 68). The authenticity of the card is verified by the combination of these different identification data (11,48), for example, the second and third identification data can be combined (70) to produce an algorithm that is compared with the first data of identification for card authentication (78, 8

Description

IMPROVEMENT IN THE SECURITY OF A CARD WITH CHIP BACKGROUND OF THE INVENTION This invention relates to the provision of improved security in so-called chip cards, sometimes also referred to as "smart cards". A chip card is an object the size of a credit card (ie, about 2-1 / 8 inches wide, 3-3 / 8 inches long, and 30 thousandths of an inch thick) made of a plastic such as polyvinyl chloride and incorporating an integrated circuit (chip) such as a microprocessor. The integrated circuit or chip includes a changeable (rewritable) memory, and is arranged to be powered by an external power supply and to exchange data (input / output) with an external terminal when the card is inserted into the terminal. Such cards are usually used, or proposed to be used, for various tasks such as access, identification, and the development of financial transactions. An illustrative type of chip card, to which, however, the present invention is not limited, is disclosed in U.S. Patent No. 4,105,156, the disclosure of which is incorporated herein by reference.

By way of example, a chip card can be designed and used for financial transactions such as obtaining cash from off-line ATM machines, that is, terminals not connected to a central computer that stores the cash. Account information of the cardholder. For example, the value (a quantity of money) can be stored in a letter with a chip by a cardholder in a terminal connected to the central computer of the cardholder's bank; the amount thus stored is debited from the account of the cardholder by the central computer. In an off-line ATM, the owner of the card can then obtain cash from the amount stored on the card by typing the amount to be withdrawn, and the off-line ATM will rewrite, in the rewritable memory of the chip card, the amount (if any) remaining on the card. The chip can also register the transaction. It is known to provide a traditional credit card, access card or identification card with a magnetic strip for security purpose, and to provide such a card with a hologram as a security device, that is, to prevent counterfeiting, since holograms are difficult to copy successfully. Furthermore, it is known to combine a hologram with a magnetic tape as security devices for credit cards, as described in the American patented Humerus 4,684,795, the disclosure of which is incorporated herein by this reference. Such a combination of magnetic strip / hologram with different data set respectively encoded in the hologram and the magnetic tape, for authentication by a reading device having both magnetic head and optical head, is described in U.S. Patent No. 5,336,871, the disclosure of which is incorporated herein by this reference. A particular arrangement for encoding such optical data in a hologram is described in U.S. Patent No. 5,432,329, the disclosure of which is incorporated herein by this reference. In the case of the chip card present, however, security is provided by a computer-directed cryptography, along with certain built-in physical features such as fuses that are designed to make the chip difficult to attack. The chip includes a read-only / written memory only once (ie an EPROM) as well as the changeable or rewritable memory. A security code, such as a personal identification number (PIN), is written in the EPROM memory. The PIN can be encrypted on the chip; the integrated circuit may be designed in such a way that the PIN stored in its read-only memory is inaccessible by ordinary means. When the card is inserted into a terminal such as an ATM, the owner of the card types the PIN in the terminal; Both the terminal and the chip can compare the typed and stored numbers and authenticate the card by determining that the two numbers are identical. If, however, the owner of the card is unable to supply the correct PIN within a limited number of attempts, the terminal may render the card unusable with an electrical pulse that acts on one or more fusibles by interconnecting elements of the card. chip circuitry. Chip cards are nonetheless potentially vulnerable to various types of attacks, both physical and cryptographic. These are unreliable, and easily damaged by thieves. The chip maker can be subverted so that other chips appear on the market, identical to the genuine chips used in cards, and a criminal with the intelligence and information to use them can undertake to copy the features that the genuine user entered in the chip to protect it It is to be expected that tried and ultimately successful, attempts were made to break the codes or endanger the protective encryption of chip cards, especially those in which significant information or wealth is stored. Also, it may be possible to make extra chips and feed it with money.

The aforementioned US Patents Nos. 4,105,156 disclose chip card security method in which a single random number is written in a read-only memory (ROM) at the point of manufacture and used in conjunction with another number, such as a number of ID. This security fix can be scrapped, without manipulating the cryptography of the original chip, replacing a new but similar chip to the original chip. Such a possibility is available to counterfeiters having a supply of similar virgin chips that can be written with the unique random number recoverable, by means of this duplicating exactly the chip to be falsified. It may be desirable, from the improved security point of view, to provide a chip card in which the chip can not be removed from one card and inserted into another card or replaced with another chip. BRIEF DESCRIPTION OF THE INVENTION The present invention, in a first aspect, meets the provision of a method of improving the security of a credit card containing an integrated circuit including a changeable memory and a read-only memory and writable a once. The method of the invention, in this gross sense, comprises the steps of first writing the identification data into the read-only memory and writable only once; establishing, on an external surface of the card, an optically readable portion comprising an optically readable variable device (OVD) such as a holographically generated OVD (here called a hologram) or a diffractive pixelgram or grid, generated or not holographically, having coded in this second identification data; and also establishing, on an external surface of the card, a magnetic strip having this identification data encoded in this third, the first, second and third identification data being combined to verify the authenticity of the card. In particular, the OVD can be an optically variable light diffraction device; it is usually pre-ferred to employ a hologram as the optically variable light diffraction device. Also, in a normally preferred embodiment, the step of establishing the optically readable portion comprises superimposing the optically readable portion on the magnetic tape. The write step may comprise encrypting the first identification data in the read-only / writable memory only once. The invention in a crude sense is not limited to any particular procedure or protocol for combining the first, second and third identification data.

For example, the second and third (optically and magnetically encoded) identification data can be combined by a predetermined manipulation or sequence of manipulations to generate or derive four identification data which (if the card is authentic) are identical to the first ones ( chip memory) identification data; the combination of the first, second and third identification data in such cases includes the steps of manipulating the second and third identification data to obtain the fourth identification data and comparing the fourth identification data with the first identification data. Thus, as used in this description, the term "combining" identification data includes comparing identification data to determine whether or not they are identical. In this sequence of example operations, access to the exchangeable memory of the card can only be achieved if the first and certain identification data match. In a second aspect, the invention contemplates the provision of a chip card comprising a card body; an integrated circuit mounted in this letter body and including a changeable memory and a read-only / one-time writable memory, having first identification data written in this memory; an optically readable portion comprising an OVD made readable as described above (i.e. a hologram) on an external surface of the card, having encoded in this second identification data; and a magnetic strip on an external surface of the card having coded in this third identification data; the first, second and third identification data being combinable to verify the authenticity of the card. It is also contemplated that in some examples an optically readable portion comprises a readable OVD prepared (i.e., a hologram) containing second identification data may be provided on a chip card having first identification data written in a read-only memory , that is, without the inclusion of a magnetic strip or strip. The method and article (card) of the invention has important advantages, with respect to the security of the chip card, in that a counterfeiter must handle at least two different technologies the computer technology used in establishing the identification data in a portion of read-only memory of the chip, and the optical technology employed in establishing identification data in an optically readable portion (read-enabled OVD) of the chip in order to defeat the security of the card. Additional features and advantages of the invention will be apparent from the detailed description set forth below, together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified perspective view of a chip card of one embodiment of the present invention in a particular form. Figure 2 is an enlarged fragmentary section view, not to scale, taken along line 2-2 of Figure 1; Figure 3 is a highly simplified diagrammatic view of the circuitry mounted on the card of Figure 1; Figure 4 is a perspective view of a device for reading the optical and magnetic security portion of the card of Figure 1; and Figure 5 is a block diagram of an authentication method of the chip card of Figure 1. DETAILED DESCRIPTION Figure 1 and 2 shows a chip card 10, ie a plastic card (i.e. polyvinyl chloride) ) typically having a thickness of about 30 thousandths of an inch and substantially the same length and width dimensions as a current ordinary credit card, containing externally connectable electrical circuitry in the form of an integrated circuit or chip 11 mounted in the card, being, for example, secured in three layers 10a and 10b of the plastic forming the card, although the chip may be at least partially exposed on one surface of the card. An example of such a card is a stored value card, in which the amount of money stored can be decreased in off-line terminals. The chip can, for example, be an integrated circuit of the type described in the aforementioned U.S. Patent No. 4,105,156. As shown in the highly simplified diagrammatic representation illustrated in Figure 3, this chip includes a one-time write / read-only memory (ie EPROM) 12, a changeable memory 14, and a processor 16 operatively connected to the memories 12 and 14. The processor is connectable to an external power supply (not shown) through the conductor 17, and the input / output conductor 18 is also provided for a two-way data communication between the chip and a computer terminal (not shown) external to the card. These connectors commonly constitute or are contained in a portion of the chip exposed on the surface of the card, although the types of connectors do not require such exposure are also known and can be used. The first identification data is permanently written into the read-only memory 12 for its use, as explained hereinafter, in a procedure to verify the authenticity of the card. Such a card may or may not be encrypted. The design and operation of the chip 11 is such that it allows access to the exchangeable memory 14, and carry out transactions using the card, only after the verification has been carried out. As a particular feature of the present invention, in the illustrated embodiment, the plastic substrate of chip card 10 contains an elaborately produced magnetic strip / OVD, exemplified herein by a magnetic / holographic strip 19, mounted on an external surface. so as to be readable both optically and magnetically by an external device to the card. The magnetic / holographic strip 19 can be of a type described in the aforementioned U.S. Patent No. 5,335,871. This strip 19 is advantageously a laminated composition formed as described in the aforementioned U.S. Patent No. 4,684,795. Specifically, in this embodiment, a clean plastic support 22, for example a polyester sheet of from one to one thousandth of an inch, is coated with a releasable slidable coating of a commercially available clear wax compound 24. The slidable compound liberates It ensures a hologram 26 to the carrier 22 and, with the application of heat, release the carrier from the hologram 26. Interposed between the hologram and the slidable compound 24 is one or more rough coatings 28 and, optionally, a coating of glass beds. 30. The rough coat or coatings 28 are relatively hard and are conventionally used to protect the magnetic tape after it is fixed to the substrate. The coating of glass beds 30, a clear lacquer composition incorporating beads typically less than 5 μm in diameter, acts so that when the light of certain radiation strikes them, the resulting radiation can be read and measured as an additional test of the validity of the document. The hologram 26 is treated, for example with methyl ethyl ketone, to facilitate the adhesion of ferrous oxide 32. A high density mud of ferrous oxide 32 is applied to the hologram 26 by a recording coater. The ferrous oxide 32 is generally combined with an adhesive 34 which fixes the ferrous oxide particles 32 when it is dried, and in subsequent heat applications it provides the glue by which the magnetic / holographic strip 19 permanently adheres to the substrate (card 10. The magnetic / holographic strip 19 is affixed to the card by a heat stamping process that (1) activates the adhesive 34 and (2) enables the carrier 22 to be released from the hologram 26 via the slidable compound 24. carrier 22, having performed its function of providing a base on which to construct the agnostic / holographic strip, can be removed and discarded. It can be understood that, in this described embodiment, the ferrous oxide 32 constitutes a magnetic strip and the hologram 26 constitutes an optically readable portion. The ferrous oxide 32 stores coded magnetic data and the hologram 26 stores coded optical data. This is to say, as discussed more fully in the aforementioned US Pat. No. 5,336,871, to identify data that are carried by the magnetic / holographic strip and are divided into two data series (second and third identification data) encoded respectively in holographic form in the hologram 26, and magnetically encoded in the magnetic strip constituted of the ferrous oxide 32. This second and third identification data are combinable, ie by a slider (as described below) to derive or generate a fourth data identification for comparison with the first identification data encoded in the memory memory writable once / only reading chip 11 to verify the authenticity of the card, ie in an off-line or registered ATM in which the letter is presented for the purpose of obtaining cash or merchandise. The hologram 26 can be configured in any reading machine arrangement to leave the optical information, in this way the arrangement specifically described in the aforementioned U.S. Patent No. 5,336,871. Preferably in at least some examples, the optical data can be encoded in the hologram in the manner disclosed in the aforementioned US Pat. No. 5,432,329, ie, as a holographic reader machine code of the type described in the patent, for example, a bar code, a holographic flat image design, or an out of focus holographic design, in combination with an optical clock. By way of illustration, in an advantageous specific embodiment the hologram can have an off-axis bar code generated holographically invisible to the naked eye and readable by a reading machine that will not read an attempt to simulate the bar code in any other way. While, as is stated, the optical and magnetic data are preferably encoded on a strip 19 comprising a hologram superimposed on a magnetic strip, the hologram and magnetic strip can be applied to a surface portion exceeded of the card, as also explained in FIG. U.S. Patent No. 5,336,871 mentioned above. There is, however, an additional safety advantage when using a superimposed magnetic / holographic strip, manufactured in such a way as to exclude the criminal from using a regular magnetic tape and then heat-stamp a holographic sheet on it. An illustrative slide reader 36 to be used with the card 10 is shown, in a somewhat simplified form, in Figure 4. This reader is generally of the type described in the aforementioned U.S. Patent No. 5,336,871, and includes a box 38 which defines an integral document slot 40 extending along the right-hand side of the cover 42. The cover 42 defines the side walls as well as the bottom wall of the slot 40. A magnetic reading head 44 is mounted in an aperture. in one the side walls to detect the magnetic encoded data in a magnetic / holographic strip 19 of a document at the moment the documents is slid past the magnetic read head 44. An optical data reader 46 is mounted in another aperture in one of the side walls for detecting optical data encoded in a magnetic / holographic document strip 19 when the document is slid past the reader of the document. optical bytes 46. The electronic outputs of the magnetic read head 44 and the optical data reader 46 are sent to the circuitry 48 for processing as described in greater detail with reference to FIG. 5. The sliding reader 36 also includes a keyboard 50 for manually entering data, a vi-susalizer 52 for presenting data, and a data co-processor 54 for connecting the slidable reader to a local computer terminal 56. Unlike the sliding reader described in patent number 5,336,871, the end flow down 58 of the document slot 40 can be closed, to serve as a stop to position the card after it passes the optical and magnetic reading elements, and the connectors diagrammatically indicated at 60 and 62 can be mounted on a side wall of the slot for interacting with the power supply connector 17 and the input / output connector 18 of the chip 11 when the card is thus positioned a, to thereby energize the chip and provide data exchange through communication 54 between the chip and the computer of the local terminal. It will be appreciated that the apparatus of Figure 4 is merely an example of terminals with which the card can be used. The operation of the card, and the function of the security elements of this, can now be easily explained. Burly established, the hologram and the magnetic strip each contain a separate set of data (second and third identification data, respectively). Each set of data or identification data can constitute a digit or sequence or string of digits, as the first identification data encoded in the read-only / writable memory once, of the chip. The two games respectively encoded in the hologram and the magnetic strip are combinable to create an algorithm; thus, the reading process of the magnetic / holographic strip is bifurcated, with the hologram and magnetic strip each contributing a portion of the algorithm, which is then communicated to the chip and compared with the algorithm already stored in the memory. read only / writable once, chip 10. The chip is programmed to not allow a transaction to proceed, or allow access to its rewritable memory, until it is not key (the algorithm obtained by reading and combining the games data encoded in the hologram and the magnetic strip) is presented. When the card is slid, a reader that reads both the magnetic code and the optical code joins the algorithm, which must match the algorithm on the chip in order to initiate instructions to the chip card. If the reader does not read an optical signal and the magnetic number and computes the algorithm that is also permanently written on the chip card, the transaction is not allowed. In this way, the present invention provides security of access to the values or other information within the chip. The method and device described, the holographic / agnostic strip is encoded by which it can be characterized as an asymmetric identification number, composed of two separate codes which are uniquely different from each other, respectively carried by the magnetic and holographic portion. of the strip. The resulting combined code, or some portion of it, is written into the memory of only readable / writable only once on the chip. The hologram, in this combination, typically contains a relatively small, and simple part of the code, for example, three digits. In the production of holograms, by molding in a mold, several hundred different three-digit numbers are repeatedly formed. Thus, several cards will have the same holographic number. The second portion of the card numbers is permanently encoded on the magnetic strip, so that the magnetic strip that goes along with the hologram, its combined numbers constitutes or provides a unique identification number. This number may be encrypted in a manner to be determined only by manipulation of the combination of magnetically and optically encoded numbers. Also, the data sets written in the read-only / writable one-time mode of the chip may or may not be encrypted. Illustratively, in one embodiment of the present invention, a single random number written in a read-only / writable memory once, on the chip as described in the above-mentioned US Pat. No. 4,105,156 at the point of manufacture serves as a latch in the lock provided by the security system of the invention. The magnetically encoded and holographically combined numbers are used as another latch. The encrypted multiplication or assembly of the two is used as the final latch which, when written and compared, will ensure that the appropriate chip is on the appropriate card and authenticates the transaction. In the aforementioned U.S. Patent No. 4,105,156, a protective code in the form of a random number is introduced during the manufacture of the card into a first memory that is chargeable only once and is available only on the card. When employed in embodiments of the present invention, the algorithm is read on the magnetic / holographic strip and loaded on the card where it is compared internally with the stored protective code for identity; and in response to a positive result of such comparison, a released signal is produced by the card processing unit for further processing of the card.

By way of a specific illustration, in the security system of the invention as in the aforementioned US Pat. No. 5,336,871, a check digit, of which there are several versions, commonly called modules (or MOD) 9, 10, 11 or 12 can be used. Every verification digit scheme is based on the manipulation of a multiplication, division, addition of the base numbers together so that by adding a singular number at the end of the string of base numbers, the correctness is verified or authentic of the base number. Thus a serial number such as 12345 could be added to itself a digit number of verification that could be from 0 to 9 depending on the calculation of the module, for example 123453. If there was a juxtaposition or transposition of error in the number 123453, for example 132453, the check digit number could not be more the number 3 and a flag or error would be notified. As an example of such an operation, the third identification data encoded magnetically on the coded magnetic / holographic strip 19, can be the string of numbers 123458. The second identification data, encoded on the hologram (optically reachable portion) of the strip 19 , can be the singular number 4. The sliding reader combines these two data sets to produce a string of digits 4123458. In this string of digits, the "8" is the correct check digit for 412345. The circuitry Smart 48 in the slide reader, presented with the combined string 4123458, will recognize that 8 is the correct check digit in this case and will allow the security operation to proceed with the next step. holographic strip 19 out other than 4, or missing, the circuitry of the slide reader 48 could deny additional access. The encoder, which is encoded in the read-only memory / writable only once, of the chip, could be 123458. If the sliding reader verifies the combined magnetic and optical readings of the strip, it is programmed to transmit the string of numbers 123458 to the chip as the fourth identification data. The chip internally compares this string of numbers with that encoded in its read-only / readable memory only once and, finding the first and fourth identification data to be identical, allows the transaction to proceed. If, however, some other string of numbers was transmitted by the sliding reader to the chip, the processor chip will find a lack of identity between the first and fourth identification data and deny additional access. The slide-out reader and / or the chip can be programmed additionally, after a limited number of entries of any verification step, causes the terminal to send an electrical pulse that could disable the card to function, for example by acting in a or more disabling devices such as fuses (not shown) incorporated in a known manner in the chip circuitry. This operation is illustrated diagrammatically in Figure 5. When an owner of a card presents the card 10 to an off-line ATM incorporating a reader as shown in Figure 4 for the purpose of making a cash arrangement, and slides the card along the slot, the reader's code 48 reads the hologram from strip 19 as indicated at 66, reads the magnetic portion of the strip as indicated at 68, combines them as indicated at 70, and As indicated in 72, it determines if the card thus examined is validated (for example, in the example above the check digit 8 is the correct one for the chain of combined numbers 412345 derived from the coding separately from the second and third data of identification). If the reading finds the invalid data, it relieves or disables the card. If the reader finds the valid data, as indicated at 74, it transmits a portion of the string (123458) as fourth identification data to the chip 11 for further verification. The chip processor then reads the first identification data encoded in the read-only / writable memory only once on the chip as indicated in 76, compares this string of numbers with the identifier data transmitted by the sliding reader as shown in FIG. in-dica in 78, and determines if the two are identical as indicated in 80. If the processor chip does not find identity, it removes or disables the card; if it determines that the chains of compared numbers are identical, this allows the transaction to proceed. The holder of the card can type in the slider the amount of cash desired, and if the card guarantees at least this amount, determined by the changeable memory of the chip, the ATM provides this sum in cash and debits the exchangeable memory of the chip. chip for the same amount, also registering the transaction. In a modification of the method and article of the invention, the magnetic strip is omitted, and the externally readable hologram 26 is used alone, for example, mounted on the outside of the card. The hologram and the memory chip 12 in such a case separately contain data sets that must be combined (for example, in the same way as the respective data set of the hologram and the magnetic tape in the procedure of the American patent number 5,336,871, already mentioned) by the chip to verify the authenticity and allow or avoid a transaction using the card. If the magnetic strip is omitted, and only a hologram is used, using a reading machine of the holographic number, the optical number hidden in the hologram is read and the result written on the chip. From here, when the chip card is used, the reader must see and compare the optical number with the number on the chip in order to start the transaction. One advantage of the invention, in all the above described modes, is that the knowledge of two very different technologies - those of computers, and optics - for successful counterfeiting. Unless a correctly coded hologram (or other OVD reader) is corresponding with a correctly written read-only memory of a chip on the same card, the use of the card will be blocked. It must be understood that the invention is not limited to the characteristics and modalities specified here, but may be carried out in other ways without departing from the spirit of its spirit.

Claims (13)

1. CLAIMS 1. A method of improving the security of a chip card containing an integrated circuit including a changeable memory and a single-read / writable memory once, said method comprising: (a) writing first identification data in said a read-only / writable memory once; (b) establishing, on an external surface of the card, an optically readable portion comprising a variable optically readable device by a machine, having second identification data encoded; and (c) establishing, on an external surface of the card, a magnetic strip having encoded third identification data; said first, second and third identification data being combinable for verification of the authenticity of the card.
2. 2. A method as claimed in claim 1 wherein said writing step comprises encrypting said first identification data in said read-only / writable memory once.
3. 3. A method as claimed in claim 1 wherein said first identification data is identical to the fourth identifiable identification data by combination of said second and third identification data.
4. 4. A method as claimed in claim 3 wherein said writing step comprises encrypting said first identification data in said read-only / write-once memory.
5. A method as claimed in claim 1 wherein the step of establishing the optically readable portion comprises overlaying the optically readable portion on the magnetic strip.
6. 6. A method as claimed in claim 1 wherein said optically variable device is a hologram.
7. 7. A method of improving the security of a chip card containing an integrated circuit including a swappable memory and a read-only / writable one-time memory, said method comprising: (a) writing first identification data in said memory read only / writable once and (b) establishing, on an external surface of the card, an optically readable portion comprising a variable optically readable device by a machine, second encoded identification data combinable with said first identification data having to be coded to verify the authenticity of the card.
8. 8. A method as claimed in claim 7 wherein said optically variable device is a holsgram.
9. 9. A chip card comprising: (a) a card body (b) an integrated circuit mounted on the card body and including a changeable memory and a read-only / writable memory once having first written identification data; (c) an optically readable portion by selecting optically readable variable device by a machine on an external surface of the card, having second identification data encoded; and (d) a magnetic strip on an external surface of the card having coded in this third identifying data; said first, second and third identification data being combinable to verify the authenticity of the card.
10. 10. A card or the like, as claimed in claim 9, wherein the optically readable portion is superimposed on the magnetic strip.
11. 11. A method as claimed in claim 9 wherein said optically variable device is a hologram.
12. 12. A chip card comprising: (a) a card body (b) an integrated circuit mounted on the card body and including a changeable memory and a read-only / writable memory once having first written identification data; (c) an optically readable portion comprising an optically variable device readable by a machine on an external surface of the card, wherein second identification data encoded with said first data is coded by a method for verifying the authenticity of the card.
13. 13. A method as claimed in claim 12 wherein said optically variable device is a hologram.