FR2901079A1 - METHOD FOR SECURING A CHIP CARD TRANSACTION, WRITE TERMINAL FOR SECURING SUCH TRANSACTION, AND SECURED CHIP CARD - Google Patents

Abstract

The invention relates to a method for securing a transaction using a payment means (1), said payment means comprising generation means (3) capable of generating cryptograms, and a magnetic stripe (2). ), said method comprising the steps of: - generating, using said generating means (3), a cryptogram, said cryptogram being uniquely associated with said transaction; - encoding said cryptogram (8) on said magnetic tape (2).

Description

METHOD FOR SECURING A CHIP CARD TRANSACTION, TERMINAL

  The present invention relates to a method of securing transactions, particularly in the context of a credit card transaction.

  The invention also relates to a means of payment, in particular a bank card.

  The invention also relates to a writing terminal adapted to be associated with a means of payment.

  Methods are known for securing transactions using a means of payment, for example a bank card comprising an electronic chip. Such security methods are for example based on the EMV standard. According to the EMV standard, during the execution of a transaction and when the chip card is inserted into an electronic chip reader, the chip generates a cryptogram associated with the transaction, in particular according to an identifier. of the transaction. The cryptogram generated is therefore unique for the transaction to be performed. This cryptogram is for example generated using a Generate Application Cryptogram application in English, or Generate an application cryptogram in French known from the EMV standard.

  The smart card reader then sends this cryptogram to a payment institution, for example a bank. The bank verifies the cryptogram received and then authorizes the transaction.

  Methods are thus known for securing a transaction using a payment means, said payment means comprising generating means capable of generating cryptograms, said method comprising the steps of: generating, using said generation means, a cryptogram, said cryptogram being uniquely associated with said transaction.

  In known methods, in particular the EMV standard, a transaction terminal comprising an electronic chip reader issues a request to the generation means for generating a cryptogram, and this cryptogram is transmitted to a payment institution for authentication.

  However, a number of transaction terminals are not equipped with a chip reader, and therefore can not issue a request to the generation means for generating a cryptogram. For these transaction terminals without a chip reader, the data stored in this chip, or the calculation capabilities of a chip can not be used advantageously.

  The methods of securing transaction by cryptogram generation uniquely associated with a transaction are therefore not usable when the transaction terminals do not allow the reading of a chip of the payment means.

  An object of the invention is therefore to secure transactions when the transaction terminals are not equipped with an electronic chip reader.

  Another object of the invention is to avoid the need to set up new transaction terminals 10 equipped with EMV-compatible smart card readers, while maintaining a good level of transaction security. The invention can indeed be used in an existing banking infrastructure, whether or not it is equipped with a smart card reader. In addition, to receive payments, terminals read a bank card via a magnetic tape including data relating to the official holder of the bank card. However, transactions via this single magnetic stripe are poorly secured. Indeed, the magnetic tape is an area which is not protected in reading, and the data of this zone are easily accessible to the fraudsters, for example by copying data from the tape, which then makes it possible to duplicate the card and to use his clone to make transactions.

  Methods for securing transactions by magnetic stripe are known. These methods are based on learning the purchasing habits of the owner of the card, for example by mathematical and statistical methods involving neural networks. According to these known methods, if a purchase not provided by the network is made using the magnetic stripe, the bank will refuse to authorize the transaction or will make a phone call to the mobile of the card holder to ask him agreement.

  However, it is understood that such methods 10 prevent the official owner of the card from being free of his transactions.

  The invention aims to overcome the disadvantages of the prior art in terms of securing transactions. An object of the invention is to provide an alternative to the methods of securing transactions by magnetic strips, while leaving a perfect freedom of transaction to the owner of the magnetic stripe card. Another object of the invention is to improve the level of security in transactions involving a magnetic stripe reader and a magnetic stripe of a means of payment and in particular a bank card without the need to upgrade. physical day of the infrastructure.

  Another object of the invention is to improve the level of security in transactions involving a bank card comprising a magnetic stripe and at least one electronic chip, while allowing the transaction to be carried out with the aid of a magnetic tape writing terminal.

  Another object of the invention is to reduce fraud related to the use of magnetic tapes of payment means and in particular bank cards.

  At least one of these objects is achieved according to the present invention which relates to a method for securing a payment by means of a payment means, said payment means comprising generation means capable of generating cryptograms, and a magnetic strip said method comprising the steps of: - generating, by means of said generating means, a cryptogram, said cryptogram being uniquely associated with said transaction; - Encode said cryptogram on said magnetic tape.

  The means of payment is in particular a smart card and the generation means are for example an electronic chip including a processor capable of performing calculations, and a data memory.

  With the method according to the invention, a cryptogram generated by the generating means is encoded on the magnetic strip of the card. This cryptogram encoded on the magnetic tape corresponds to a unique identifier of the transaction made and guarantees the security of this transaction. Thus, according to the invention, the cryptogram encoded on the magnetic tape can be transmitted to a payment institution, for example a bank. Authentication of the cryptogram received by the bank is then performed by performing the same calculations and transformations as those that allowed the generation and encoding of the cryptogram on the magnetic tape.

  The level of security of payments is thus improved by the invention.

  For example, if a fraudster manages to copy the magnetic stripe of the smart card on which the cryptogram is encoded, he will not be able to use the card to perform other transactions because the cryptogram encoded on the magnetic stripe is a unique identifier. of the transaction and can only be used once, like one time password (OTP).

  Moreover, in order to enable the recording of the data on the magnetic tape, said method can also be implemented by means of a write terminal able to communicate with said payment means and said method can comprise steps in which: said write terminal generates a request to said generating means; said generation means generate said cryptogram in response to said request; said writing terminal encodes said cryptogram 30 on said magnetic tape.

  In this way, a user in possession of the writing terminal, for example portable, can perform himself his registration at the magnetic stripe of the smart card, without the transaction terminal at which the transaction is made is equipped with a smart card reader. The writing terminal may also be available from a merchant at whom the transaction is made. In this case, the card holder uses the writing terminal to encode the cryptogram on the magnetic strip of his smart card. This is made possible by the fact that the invention does not require to uniquely associate a terminal with a card.

  In addition, so that the transaction terminal intended to transmit a transaction authorization request to a payment institution can read the encrypted cryptogram on the magnetic strip of the payment means without modifying the existing transaction terminals, said transaction is carried out at using a transaction terminal to a payment institution, said transaction terminal comprising a magnetic stripe reader able to read data from said magnetic stripe, and wherein said method can comprise steps in which: said reader magnetic tape reads said cryptogram encoded on said magnetic tape; said encoded cryptogram is transmitted to said payment institution by said transaction terminal.

  In this way, the card is used as a magnetic stripe card known at the time of the transaction itself, and the new data of the magnetic tape corresponding to the encoded cryptogram can be transmitted in a known manner by the transaction terminal to the payment institution.

  Furthermore, in order to respect the constraints of the data of the magnetic tape, the encoding step may comprise steps of: -formatting said cryptogram according to a data format of said magnetic tape, so as to generate a cryptogram formatted; register said cryptogram formatted on said magnetic tape.

  In this way, the formatted cryptogram inscribed on the magnetic tape respects the constraints of this magnetic tape, especially in terms of data size. The cryptogram thus encoded can then be read by known magnetic tape readers. Moreover, in order that the cryptogram encoded on the magnetic tape is correctly read and interpreted by a magnetic tape reader, said magnetic tape comprises a writing zone reserved for a payment institution, and said cryptogram may be encoded on said magnetic tape reader. magnetic tape in said writing area reserved for a payment institution.

  For the purposes of the present application, it is indeed called 30 writing area reserved for a payment institution, any area of the magnetic strip reserved for the proprietary data of the issuer of the means of payment. This zone is known to those skilled in the art under the name Issuer Proprietary Data or proprietary data of the issuer in French.

  In this way, the cryptogram can be read by existing readers, transmitted over existing networks and interpreted by a payment institution receiving the cryptogram. Moreover, the inscription on a writing area reserved for a payment institution makes it possible not to alter the processing of the payment using the data contained in the magnetic strip according to the prior art.

  The invention also relates to a payment means comprising generating means capable of generating a cryptogram, said cryptogram being uniquely associated with a transaction, characterized in that said payment means comprises a magnetic tape on which said cryptogram is encoded.

  Such a means of payment can therefore be read by a known magnetic tape reader so as to transmit the cryptogram encoded on the magnetic tape to a payment institution to perform the authentication of the transaction.

  In one embodiment, in order to respect the constraints of the data of the magnetic tape, the payment means may comprise first formatting means able to format said cryptogram according to a data format of said magnetic tape into a formatted cryptogram, and said formatted cryptogram may be inscribed on said magnetic tape.

  The payment means is for example a bank card and said generation means comprise for example an electronic chip, said electronic chip comprising at least one processor and data storage memories.

  The invention also relates to a writing terminal adapted to be associated with a payment means, said payment means comprising generation means capable of generating cryptograms, and a magnetic tape, said writing terminal comprising: - means command capable of triggering a generation of a cryptogram by said generating means; encoding means able to encode said cryptogram on said magnetic tape.

  According to one embodiment of the aforementioned writing terminal, said encoding means may comprise second formatting means able to format said cryptogram according to a data format of said magnetic tape so as to generate a formatted cryptogram, and means of inscription adapted to inscribe said cryptogram formatted on said magnetic tape.

  According to one embodiment of the invention, said magnetic tape comprises a writing zone reserved for a payment institution, and said registration means can be arranged so as to write said encrypted codeform on said magnetic tape in said data zone. reserved for a payment institution. An embodiment of the invention will now be described with reference to the appended figures in which:

  FIG. 1 illustrates a bank card for implementing the method according to the invention; Figure 2 is an example of the main elements of the chip of a bank card as illustrated in Figure 1; Figure 3 illustrates a write terminal according to the invention; FIG. 4 illustrates a method for securing a payment according to the invention; FIG. 5 illustrates a detailed architecture of the terminal of FIG. 3, in association with the card of FIG. 1. Illustrated FIG. 1, a payment means 1 according to the invention can be a smart card 1. The smart card 1 comprises at least one chip 3 and a magnetic strip 2. It is for example in accordance with the ISO 7816 standard for a contact card. The smart card 1 has been issued by a payment institution to which the card 1 requests payment authorizations to make payments.

  The magnetic tape 2 may comprise authentication data of the legitimate user of the smart card 1. The data is for example stored on the magnetic tape 2 in accordance with the ISO / IEC 7811 standard on three magnetic strings of the magnetic tape. 2.

  The chip 3 comprises, in a manner known per se, data memories and at least one processor able to perform calculations on the stored data. FIG. 2 illustrates an example of an electronic chip structure in a smart card 1.

  Illustrated in FIG. 2, the chip 3 comprises, for example, a central processing unit or processor 12 operatively connected to a set of memories of which: a memory 13 accessible in read-only mode, in the example of the type ROM mask, also known as the English name mask Read-Only Memory or Mask ROM, - an electrically reprogrammable memory 14, in the example of the EEPROM type (of the English "Electrically Erasable Programmable ROM"), and - a working memory 15 accessible in reading and in writing, in the example of the type RAM (of English "random access memory"). This memory 15 comprises in particular the registers used by the chip 3.

  The executable code corresponding to the calculation algorithms produced by chip 3 using processor 12 is in program memory. This code may in practice be contained in memory 13, accessible in read only, and / or in memory 14, rewritable.

  An encryption key for the implementation of the calculation algorithms within the chip 3 can also be stored in the memories as previously described.

  The central unit 12 is connected to a communication interface 16 which ensures the exchange of signals vis-à-vis the outside and the supply of the chip.

  This interface may include pins on the card for a so-called contact connection with a reader, and / or an antenna in the case of a so-called non-contact card.

  A method of securing a transaction and a device for such securing with reference to FIG. 3 to FIG. 5 are now described.

  Illustrated in FIG. 4, in a step 10, before carrying out a transaction at a transaction terminal, a smart card 1 is inserted in a write terminal 4 in the example of a contact card.

  The writing terminal 4 is described in more detail in FIG. 3 and FIG.

  The writing terminal 4 has, for example, been delivered to the card holder 1 by the payment institution issuing the card 1. It comprises in particular a card reader 5 to which the card can be associated for a transaction, for example in which the smart card 1 can be introduced. It may also include a screen 6, and / or an alphanumeric keyboard 7.

  Illustrated in FIG. 5, the write terminal 4 is represented in particular when a smart card 1 is inserted in this write terminal 4 at the reader 5. The writing terminal comprises feed means 17 adapted to supplying the chip 3 when the card 1 is inserted in the writing terminal 4. It also comprises reading means 18 able to read data stored in one of the readable memories of the chip 3. For the purposes of the present invention, the term of reading data in the chip 3 means in a manner known per se for the skilled person a double request step received by the chip 3 and data transmission according to the request. It also includes formatting means 19 capable of formatting data read by the reading means 18. The formatting performed in the context of the present invention will be discussed in more detail below. It finally comprises registration means 20 able to write data formatted by the formatting means 19, on the magnetic strip 2 of the card 1. The registration means 20 comprise for example a magnetic field generator for orienting the magnetic strips of the magnetic tape 2 in a writing zone of the magnetic tape 2. The writing means 20, the formatting means 19 and the reading means 18 form encoding means capable of encoding data of chip 3 of the card 1 on the magnetic strip 2.

  According to the invention, when the card 1 is inserted in the reader 5, the supply means 17 feed the chip 3, for example according to the ISO 7816 standard.

  According to the EMV standard following this power up, the chip 3 initiates an initialization phase, then the transaction is started. The reading means 18 then read data from the chip 3 to determine whether verification modes of the card holder 1 are supported by the chip 3.

  According to the invention, a verification mode is for example the authentication of the carrier by PIN code. If this PIN verification is supported by the chip 3, the terminal 4 generates a PIN code request to the user via the screen 6. The user can then enter his PIN code, for example, to the user. keyboard help 7.

  If the PIN code is correct, control means 21 then command the chip 3 to generate a cryptogram uniquely associated with the transaction. This request is for example carried out according to the EMV standard by the Generate Application Cryptogram function in English language, or Generate an application cryptogram in French language.

  The cryptogram generated according to the invention may be a cryptogram based on a time synchronization between a clock of the terminal 4 and a clock of a bank authorizing or not the payment. It can also be a cryptogram based on a counter located in a memory of the card 1 and synchronized with the bank. The different types of cryptogram generation methods uniquely associated with a transaction are known and will not be described in more detail in this patent application. For the generation of the cryptogram, the chip 3 implements, in a manner known per se, cryptographic algorithms using a cryptographic device, for example according to the EMV standard. Once the cryptogram generated by the chip 3, the reading means 18 of the write terminal 4 then read this cryptogram stored in memory of the chip 3.

  The formatting means 19 of the terminal 4 then format this cryptogram so as to be able to write it on the magnetic strip 2 of the card 1. The formatting carried out is in accordance with the standards used for the data of the magnetic tapes in the banking field. Such a format is, for example, in accordance with the ISOIIEC 7811 standard.

  In general, the formatting of the cryptogram is carried out in accordance with the constraints of the magnetic tape 2, and in particular according to the constraints of data sizes. For example, if the cryptogram has a size of about eight bytes and the available size on the magnetic tape is only one byte, the formatting means 19 truncate the cryptogram so as to generate a formatted cryptogram. This formatted cryptogram corresponds to a unique identifier of the transaction.5 It is understood that if the magnetic stripe can contain the entire cryptogram without limitation on the size of the cryptogram, it can be directly written on the magnetic stripe 2 without prior truncation.

  Once the cryptogram has been formatted, the inscription means 20 inscribe this cryptogram formatted on the magnetic strip 2 of the card 1. This inscription is made in a manner known per se by generating a magnetic field capable of polarizing magnetic strips of the magnetic tape according to the data to be entered, for example on three tracks.

  The formatted cryptogram is for example written on a writing zone of the magnetic strip 2 reserved for the card issuer's payment institution 1 corresponding to a zone reserved for the proprietary data of the issuer of the means of payment. This zone is known to those skilled in the art under the name Issuer Proprietary Data or proprietary data of the issuer.

  When the cryptogram is written in such a write zone, the formatting described above is adapted to such a writing area, especially in terms of data size.

  The registration means 20 are then positioned in the terminal 4 so as to perform the registration in this writing area of the magnetic tape 2 reserved for the payment institution.

  Once the encoding is carried out in the writing area reserved for the payment institution of the magnetic strip 2 of the smart card 1, the terminal 4 for example sends an end-of-registration message via the screen 6 to the user.

  With reference to FIG. 4, as previously described, the terminal 4 thus makes it possible to encode a cryptogram 8 on the magnetic strip 2 of the card 1 during an encoding step 20. As previously described, this encoding comprises a step of formatting the cryptogram to respect the constraints of the magnetic tape 2, and a step of writing this cryptogram formatted on the magnetic tape 2.

  The user can then use in a step 30, his card 1 with a transaction terminal 9. According to the invention, the transaction terminal 9 is a standard tape drive terminal connected to a standard network.

  To carry out a transaction, the card 1 is thus slid in a manner known per se at the tape drive 2, and the data of the magnetic tape 2 are transferred to the banking institution 11 in a step 40. It is noted that as the cryptogram 8 has been formatted in accordance with the data standard of the magnetic stripe, the magnetic stripe reader can correctly interpret the data of the magnetic stripe 2, and no reading error will be induced by the addition of the cryptogram 8.30 The institution Bank 11 therefore receives the data from the magnetic tape 2 and a request for authorization from the transaction terminal 9. In addition to verifications made in a known manner in the context of a transaction authorization request and carried out at the of an authorization server of the banking institution 11, the authorization server also checks the cryptogram received thanks to a symmetric reconstruction that i was done in the map.

  The authentication server can then decide to authorize or not the transaction in a step 50 according to predetermined criteria by each institution. In particular, if the received cryptogram is authenticated, the authentication server authorizes the transaction.

  For example, using the same cryptographic algorithms used by the card 1 and with the same key, the bank calculates the value expected for the cryptogram associated with the transaction, optionally performs a formatting and compares this expected value with the value received from the card. magnetic reader. If the two values match, she can authorize the transaction.

  Following are variants of the invention. An embodiment has been described above in which the write terminal 4 requests the bearer of the card 1 to enter a PIN code.

  It is understood that other means of verifying the identity of the carrier can be implemented at the terminal 4 in the context of the invention, and for example a biometric control of the identity.

  Also according to the invention, the terminal 4 does not require authentication by PIN code, and in this case, the control means 21 control the chip 3 to generate the cryptogram from the association of the card 1 to the terminal of writing 4.

  The cryptographic algorithms implemented at chip 3 may be such that the cryptogram comprises a portion representative of a preliminary verification or not by PIN code and possibly a part representative of the success or otherwise of the prior verification.

  In the latter case, depending on the desired level of security, the bank 11 may authorize the transaction even if the cryptogram received contains a data representative of the absence of verification by PIN code, or conversely, the bank 11 may refuse the transaction if the cryptogram received does not contain a piece of data representing a verification by PIN code.

  Also according to the invention, an embodiment has been described in which the formatting of the cryptogram, for example in the form of a truncation for putting the cryptogram in a form compatible with the magnetic tape 2, is carried out by means of formatting the Writing terminal 4. According to a variant of this embodiment, this formatting is performed directly by the chip 3 following the generation of the cryptogram. The chip 3 thus possibly comprises formatting means capable of formatting the cryptogram according to the constraints of the magnetic tape 2.

  According to the invention, in order to facilitate the processing of the authorization server of the banking institution 11, it is also possible to write on the magnetic strip 2 other data, for example a counter, in addition to the cryptogram 8.

  Finally, the invention has been described in the context of a bank card, but it is understood that the invention relates to any card capable of enabling a transaction and comprising an electronic chip and a magnetic strip, such as a loyalty card. , a private card, or a tanker card.

Claims (13)

  A method for securing a transaction using a payment means (1), said payment means comprising generation means (3) capable of generating cryptograms, and a magnetic tape (2), said method comprising steps of: - generating, using said generating means (3), a cryptogram, said cryptogram being uniquely associated with said transaction; - Encode said cryptogram (8) on said magnetic tape (2).   2. Method according to claim 1, wherein said method is further implemented using a write terminal (4) adapted to communicate with said payment means and said method comprises steps in which: said write terminal (4) generates a request to said generation means; said generation means (3) generate said cryptogram in response to said request; said writing terminal (4) encodes said cryptogram on said magnetic tape (2).   3. Method according to one of the preceding claims, wherein said transaction is performed using a transaction terminal (9) to a payment institution (11), said transaction terminal (9) comprising a tape device magnetic sensor adapted to read data from said magnetic tape, and wherein said method comprises steps in which: said magnetic tape reader reads said cryptogram encoded on said magnetic tape; said encoded cryptogram is transmitted to said payment institution by said transaction terminal (9).   4. Method according to one of the preceding claims wherein the encoding step comprises the steps of: - formatting said cryptogram according to a data format of said magnetic tape, so as to generate a formatted cryptogram; Inserting said cryptogram formatted on said magnetic tape.   5. Method according to one of the preceding claims, wherein said magnetic tape comprises a writing area reserved for a payment institution, wherein said cryptogram is encoded on said magnetic tape in said writing area reserved for an institution. of payment. 25   6. Method according to one of the preceding claims, wherein said payment means is a bank card and wherein said generation means comprise an electronic chip, said electronic chip comprising at least one processor and data storage memories.   7. A payment means (1) comprising generating means (3) capable of generating a cryptogram, characterized in that said payment means comprises a magnetic tape on which said cryptogram is encoded.   8. A method of payment (1) according to claim 7, comprising first formatting means adapted to format said cryptogram according to a data format of said magnetic tape into a formatted cryptogram, and wherein said formatted cryptogram is inscribed on said tape. magnetic.   9. A method of payment according to claim 7 or 8, wherein said payment means is a bank card and wherein said generation means comprises an electronic chip, said electronic chip comprising at least one processor and data storage memories.   10. A method of payment according to one of claims 7 to 9, wherein said magnetic strip comprises a writing area reserved for a payment institution and wherein said cryptogram is encoded in said writing area reserved for a credit institution. payment.   11. Writing terminal (4) adapted to be associated with a payment means (1), said payment means (1) comprising generation means (3) capable of generating cryptograms, and a magnetic tape (2) , said write terminal comprising: control means (21) able to trigger a generation of a cryptogram by said generation means; encoding means (20, 19, 18) capable of encoding said cryptogram on said magnetic strip.   12. Writing terminal according to claim 11, wherein said encoding means comprise second formatting means (19) capable of formatting said cryptogram according to a data format of said magnetic tape so as to generate a formatted cryptogram. , and registration means (20) adapted to inscribe said cryptogram formatted on said magnetic tape. 15   The write terminal of claim 12, wherein said magnetic stripe includes a write area reserved for a payment institution, and wherein said write means is arranged to write said cryptogram formatted on said stripe. in said writing area reserved for a payment institution.