FR3038417A1 - SERVER AND METHOD FOR VERIFYING DYNAMIC SECURITY CODE - Google Patents

Abstract

This security dynamic code verification server (5000) comprises: a communication module (5200) able to receive bank transaction data comprising an identifier and a first security dynamic code generated by a device (1000) associated with this identifying from a time data or a counter the number of first dynamic security codes generated by this device; a module (5300) for generating a second dynamic security code from the identifier and a time data or a counter of the number of second dynamic security codes generated by this module for this identifier; a module (5400) for comparing the dynamic safety codes; the communication module (5200) being able to send to a server (6000), and only if the dynamic codes are equal, said transaction data in which the dynamic security code is replaced by a static security code associated with the device (1000), said server (6000) being configured to check the validity of said security code to allow or deny said transaction.

Description

Background of the invention

The present invention is in the field of verification mechanisms of security codes. In particular, the invention can be used to verify security codes such as identification document numbers, social security identifiers, door opening codes, or website access codes. The invention also finds a preferred application for verifying security codes used in banking transactions, for example online payment applications.

Particularly known in the field of banking transactions, microcircuit cards associated with bank accounts, transactions and online transactions made using such a card being secured using a security code associated with the card.

Most often, these security codes are said to be static, which means that they are constant over time, that is, their value remains the same throughout the lifetime of the card.

A known problem with these bank cards is that it is relatively easy to steal the static security code, especially when it is printed on the bank card.

The document [REFAA] proposes a solution to secure online transactions by means of a bank card, in which the security code displayed on the card and entered by the user to perform a transaction is a dynamic security code, the computer processing system of the online transaction financial service being able to check the validity of this dynamic security code according to a time parameter to validate or not the transaction.

Unfortunately, the solution proposed in this document has a major disadvantage in that it requires a complex modification of the transaction authorization system of the bank's server. The invention proposes a solution for verifying a security code that does not have this drawback.

Object and summary of the invention

More precisely, and according to a first aspect, the invention relates to a dynamic security code verification server comprising: a communication module able to receive banking transaction data comprising an identifier and a first dynamic security code generated by a device associated with this identifier from a time data or a counter of the number of first dynamic security codes generated by said device; a module for generating a second dynamic security code from said identifier and a time datum or a counter of the number of second dynamic security codes generated by said module for this identifier; a comparison module of the first and second dynamic security codes; the communication module being able to send to a server, and only if the first and second dynamic security codes are equal, the aforementioned transaction data in which the dynamic security code is replaced by a static security code associated with the device, this server being configured to check the validity of said security code to allow or refuse said transaction.

Correlatively, the invention proposes a method for verifying a dynamic security code comprising: a step of receiving bank transaction data comprising an identifier and a first dynamic security code generated by a device associated with this identifier from a time data or a counter of the number of first dynamic security codes generated by this device; a step of generating a second dynamic security code from said identifier and a time data or a counter of the number of second dynamic security codes generated by this module for this identifier; a step of comparing the first and second dynamic security codes; a step of sending to a server, and only in case of equality of the first and second dynamic codes, of the aforementioned transaction data in which said dynamic security code is replaced by a static security code associated with the device, this server configured to check the validity of the security code to allow or deny the transaction.

Thus, and in a general manner, the invention proposes according to this first aspect, to verify the validity of the dynamic security code for the transaction upstream of the server configured to allow or refuse the transaction, and when the validity of the dynamic code is verified to substitute this dynamic security code with a static security code for it to be verified by this server.

The server configured to allow or deny the transaction does not need to be modified to be able to check the dynamic security codes.

In particular, when the invention is used in the banking field, the bank servers do not have to be modified, the verification of the dynamic security code being performed upstream in the network.

This solution is very advantageous because it does not require any other modification in the transaction chain, since in fine, the authorization or the refusal of the transaction remains under the responsibility of the server at the end of the chain, the banking server for example.

In a particular embodiment, the security code verification server according to the invention is configured to send a refusal message of the transaction to a server capable of performing the transaction if the first and second dynamic codes are different.

Thus, in this embodiment, the server configured to check the validity of the static security code to allow or refuse the transaction, the bank server for example, is not solicited. The invention also relates to a system for verifying a security code comprising: a dynamic security code verification server as mentioned above; the server configured to check the validity of said static security code to authorize or refuse said transaction; and an interface module able to receive transaction data comprising either a static security code or a dynamic security code and to transmit said transaction data to the security dynamic code verification server according to the invention if the transaction data comprises a dynamic security code; or - the server configured to check the validity of said static security code if the transaction data comprises a static security code.

In other words, in this embodiment, the invention proposes an interface module able to redirect the transaction data either to the server according to the invention or to the server configured to check the validity of said static security code (for example the bank server) according to the dynamic / static type of the security code included in the transaction data.

This interface module provides operators with a modular solution for integrating the dynamic security code verification server according to the invention into existing interbank networks.

In a particular embodiment, the security dynamic code verification server is implemented in the server configured to check the validity of the static security code (for example a bank server).

In a particular embodiment, the interface module according to the invention is also implemented in the server configured to check the validity of the static security code.

In a particular embodiment, the system according to the invention comprises: a microcircuit card comprising a static security code and a screen for displaying a dynamic security code generated by said card to perform a transaction; the dynamic security code verification server according to the invention being able to verify the validity of the dynamic security code generated by said card; the server configured to check the validity of the static security code being able to check the static security code of this card.

In one embodiment, this system comprises: a terminal allowing a user to connect to a server to perform the transaction, this terminal comprising a human-machine interface allowing the user to enter the transaction data of which said dynamic security code generated by the card for this transaction; the server for carrying out the transaction being able to transmit these transaction data to the dynamic security code verification server according to the ISO 8583 protocol.

In the embodiments described above, when the dynamic security code verification server according to the invention verifies the validity of the dynamic security code for the transaction, it requests the server configured to authorize or refuse the transaction so that the -ci verifies the static security code.

In another variant according to the invention, when the server verifies the validity of the dynamic security code it sends a message directly to the server performing the transaction, without requesting the server configured to allow or refuse the transaction, typically the bank server.

More precisely, according to this second aspect, the invention relates to a dynamic security code verification server comprising: a communication module able to receive, in a communication network, transaction data comprising an identifier and a first dynamic code; security device generated by a device associated with this identifier from a time data or a counter of the number of first dynamic security codes generated by this device, these transaction data being intended for a server configured to check the validity of a static security code to allow or deny said transaction; a module for generating a second dynamic security code from the identifier and a time datum or a counter of the number of second dynamic security codes generated by this module for this identifier; a comparison module of the first and second dynamic security codes; the communication module being able to send to a server capable of carrying out the transaction, and only if the first and second dynamic codes are equal, an authorization message for carrying out said transaction, the dynamic code verification server; security scheme being implemented in an interface equipment between the network and the server configured to check the validity of a static security code.

Correlatively, the invention relates to a security dynamic code verification method comprising: a step of receiving, in a communication network, transaction data comprising an identifier and a first dynamic security code generated by a device associated with this identifying from a time data or a counter the number of first dynamic security codes generated by this device, the transaction data being intended for a server configured to check the validity of a static security code to authorize or refuse the transaction; a step of generating a second dynamic security code from the identifier and a time data or a counter of the number of second dynamic security codes generated by the module for this identifier; a step of comparing the first and second dynamic security codes; a step of sending, to a server capable of carrying out the transaction, and only if the first and second dynamic codes are equal, an authorization message for carrying out the transaction, this method being implemented in an interface equipment between the network and the server configured to check the validity of a static security code. The invention also relates to a system for verifying a security code comprising: a microcircuit card comprising a static security code and a screen for displaying a dynamic security code generated by this card to perform a transaction; a dynamic security code verification server according to this second aspect of the invention able to verify the validity of the dynamic security code generated by said card and to send an authorization message of the transaction to a server capable of carrying out the transaction, only when the validity of said dynamic code has been verified.

In one embodiment, this system comprises: a terminal enabling a user to connect to the server to carry out the transaction, the terminal comprising a human-machine interface enabling said user to enter the data of said transaction whose dynamic security code generated by the card for this transaction; said server for carrying out the transaction being able to transmit these transaction data to the dynamic security code verification server according to the ISO 8583 protocol and to receive according to this protocol an authorization message for said transaction from this server.

In a particular embodiment, the various steps of the verification method of a dynamic security code according to the first aspect or the second aspect of the invention are determined by computer program instructions.

Consequently, the invention also relates to a computer program on an information carrier, this program being capable of being implemented in a server or more generally in a computer, this program comprising instructions adapted to the implementation of performing steps of a method for verifying a dynamic security code as described above.

This program can use any programming language, and be in the form of source codes, object codes, or intermediate codes between source code and object code, such as in a partially compiled form, or in any other desirable shape. The invention also relates to a computer-readable information medium, comprising instructions of a computer program as mentioned above.

The information carrier may be any entity or device capable of storing the program. For example, the medium may include storage means, such as a ROM, RAM, PROM, EPROM, CD ROM, DVD or hard drive. On the other hand, the information medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means. The program according to the invention can be downloaded in particular on an Internet type network.

Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

Brief description of the drawings

Particular features and advantages of the present invention will emerge from the detailed description given in the figures in which: FIG. 1 represents a device making it possible to carry out transactions, in this case a microcircuit card; FIG. 2 represents a first security code verification system according to an embodiment of the invention; FIG. 3 represents in flowchart form the main steps of a security dynamic code verification method according to an embodiment of the invention; FIG. 4 represents a second security code verification system according to an embodiment of the invention; FIG. 5 represents in flowchart form the steps implemented by an interface module of the system of FIG. 4; FIGS. 6 and 7 represent the security code verification system of FIG. 4 according to two alternative architectures; FIG. 8 represents in flowchart form the main steps of a security dynamic code verification method according to another embodiment of the invention; FIG. 9 represents a table that can be used by a security dynamic code verification server; FIG. 10 represents in flowchart form the steps implemented by a security dynamic code verification server which uses the table of FIG. 9; FIG. 11 represents another table that can be used by a security dynamic code verification server; FIG. 12 represents in flowchart form the steps implemented by a security dynamic code verification server which uses the table of FIG. 11.

Detailed description of a first embodiment of the invention

This embodiment is described in the particular context of a financial application, specifically an online payment application.

Figure 1 shows a device 1000 for performing online transactions.

In the embodiments described below, the device 1000 is a smart card (in English smartcard) payment. Alternatively, the device 1000 may be constituted by a terminal, for example mobile telephony, implementing an application to perform transactions.

In the embodiment described here, the microcircuit card 1000 is in accordance with the IS07816 standard. In particular, it comprises a contact interface 1300. The microcircuit card 1000 is, for example, in ID-1 format (dimensions: 85.60 × 53.98 mm) and is approximately 0.76 mm thick. It is for example plastic.

In known manner, the name of the card holder NIC microcircuit, a bank account number PAN (for example 16 digits), expiration date EXP are printed and / or embossed on the microcircuit card 1000. The card furthermore includes a security code CW which may or may not be printed on the card. For more information on: - the security code CW, the person skilled in the art can consult the document [REFCW]; the PAN bank account number, the person skilled in the art can consult the document [REFPAN].

This microcircuit card 1000 comprises a controller 1200 comprising a module capable of supplying the current date, for example a CLK clock, this controller 1200 being able to calculate a dynamic security code DCCVi by applying a secret cryptographic function to parameters comprising the number bank account and a time parameter.

In the embodiment described here, the dynamic security code DCCVi is varied periodically, according to a predetermined period.

On the contrary, the security code CW is constant in time.

The microcircuit card 1000 includes a display 1100 for displaying this dynamic security code DCCVi. This screen may comprise for example 3 or 4 elementary zones depending on the size of this dynamic code.

In the embodiment described here, the microcircuit card 1000 further comprises a not shown battery and a push button 1400 for turning on or off the display screen 1100 and therefore the dynamic safety code DCCVi. This push button or any equivalent means (capacitive button, ...) to turn on or off the 1100 screen is optional. The display screen 1100 may be on the face of the microcircuit card 1000 opposite that where are printed and / or embossed the bank card number PAN and EXP expiry date. Alternatively, they are on the same side.

FIG. 2 represents a user terminal 2000 equipped with an HMI human-machine interface, for example a personal computer, a smartphone or a tablet, a server 3000 of a merchant website, the banking system 6000. the entity issuing the microcircuit card 1000, and a security dynamic code verification device 5000 according to the invention.

In the embodiment described here, the terminal 2000 accesses the merchant web site 3000 through the Internet; the merchant web site 3000, the banking system 6000 and the verification device 5000 communicate via an interbank network 4000.

The banking system 6000 includes a module 6100 for authentication and authorization of banking transactions. In general, the security dynamic code verification device 5000 aims at securing the static security code CW of the microcircuit card 1000.

The security dynamic code verification server 5000 is in accordance with the invention. It comprises in particular: a module 5100 capable of obtaining the current date, either by using internal means or, for example, from another equipment or another network, by means of wireless or wired communications; a communication module 5200 capable of receiving bank transaction data DT (DCCVi) including the bank account number PAN, the expiration date EXP of the card and the first dynamic security code DCCVi calculated by the microcircuit card; 1000 for a transaction; a module 5300 for generating a second dynamic security code DCCV2 for this online transaction using the bank account number PAN, a secret cryptographic function and a time data; a module 5400 comparing the first and second dynamic security codes; a module 5800 able to receive the static security code CW of a microcircuit card or to generate this static code CW by using the bank account number PAN of the card, its expiration date EXP and a secret key to the card using a cryptographic algorithm; the communication module 5200 being able to send to the bank server 6000, and only in case of identity of the first and second dynamic codes DCCVi, DCCV2, the transaction data received from the server 3000 in which the dynamic security code DCCVi is replaced by the static security code CW obtained by the 5800 module.

In a known manner, the bank server 6000 includes an authentication and transaction securing module 6100 able to check the security code CW for authorization or refusal of the transaction. It is important to note that this check uses the security code CW so that the bank server 6000 does not need to implement the calculation functions of the second dynamic security code DCCV2.

Referring to Figure 3, we will assume that a user logs on, using the terminal 2000 to the merchant web site 3000 to complete a transaction, and that user enters (step E10) into a web page issued by the merchant site 3000 or by the server 5000 transaction data DT (DCCVi) comprising: the PAN information of the card 1000; EXP expiry date of the card 1000; and the dynamic security code DCCVi displayed on the screen 1100 at the time of this transaction.

This transaction data DT (DCCVi) is transmitted by the merchant site 3000 to the verification server 5000, in a transaction authorization request in the format IS08583. The server 5000 receives this request during a step E20. The use of IS08583 format is not required for incoming or outgoing communications from the 5000 server; another format can be used.

During a step E30, the verification server 5000 generates a second dynamic code DCCV2 for the transaction, from the data received in step E20 and a time parameter.

During a step E40, the verification server 5000 checks whether this second dynamic code DCCV2 is equal to the first dynamic code DCCVi calculated by the microcircuit card 1000.

If these dynamic codes are equal, the verification server 5000 sends, during a step E50, to the bank server 6000, the transaction data received from the server 3000 in which the dynamic security code DCCVi is replaced by the static code of CW security of the card 1000. This modified transaction data is denoted DT (CW). In a known manner, the bank that operates the bank server 6000 can be identified by a BIN code corresponding to the first digits of the PAN number.

In the embodiment described here, if the dynamic codes are different, the verification server 5000 sends a refusal message of the transaction to the server of the merchant site 3000 during a step E45. Alternatively, the verification server 5000 can send to the bank server 6000 modified transaction data DT (ÇW) with a false CW security code to trigger the refusal of the transaction by the bank server.

The authentication and transaction securing module 6100 of the bank server 6000 checks the transaction data DT (CW) received from the verification server 5000 during a step E60 to allow or refuse the transaction.

If the bank server 6000 authorizes the transaction, it sends an authorization message to the server of the merchant site 3000 during a step E70 which delivers the goods or services corresponding to the user.

If the bank server 6000 refuses the transaction, it sends a transaction refusal message to the server of the merchant site 3000 during a step E80. The authorization or refusal is sent to the merchant site server in an ISO 8583 format response response message.

DETAILED DESCRIPTION OF A SECOND EMBODIMENT OF THE INVENTION

FIG. 4 represents a security code verification system 10 comprising: a security dynamic code verification server 5000 and a bank server 6000 as described above with reference to FIGS. 2 and 3; and an interface module 5500 according to the invention.

This interface module 5500 is able to receive transaction data DT from a merchant site server 3000 comprising either a security code CW or a dynamic security code DCWi, and to decide on the processing of these transaction data into according to the static / dynamic criterion of the security code.

More specifically, with reference to FIG. 5, the interface module 5500 determines during a step F10 whether the security code included in the transaction data DT is a security code CW or a dynamic security code DCWi; and if the code is a dynamic security code, the interface module transmits these transaction data DT (DCWi) to the security dynamic code verification server 5000 for it to check the dynamic security code DCCVi (steps E30 and E40) and transmits the transaction data DT (CW) including the security code CW to the server 6000 (step E50); If the code is a static security code, the interface module transmits these transaction data DT (CW) to the bank server 6000 so that it directly realizes the processing described with reference to the steps E60 to E80 of FIG. .

Detailed description of third and fourth embodiments of the invention

In the embodiment of FIG. 4, the interface module 5500 and the security dynamic code verification server 5000 are implemented in equipment independent of the bank server 6000.

In another embodiment of the invention shown in FIG. 6, the interface module 5500 remains an independent equipment of the bank server 6000 but the security dynamic code verification server 5000 is implemented in the banking server.

In another embodiment of the invention shown in FIG. 7, the interface module 5500 and the security dynamic code verification server 5000 are implemented in the bank server 6000.

In these two embodiments, it is preferable that the functions of the interface module 5500 and the server 5000 for verifying the dynamic security code are not integrated in the authentication and transaction security module 6100 in charge of the verification of static static security code CW.

DETAILED DESCRIPTION OF A FIFTH EMBODIMENT OF THE INVENTION

In the first embodiment described with reference to FIGS. 1 to 3 and in the second embodiment described with reference to FIGS. 4 and 5, when the security dynamic code verification server 5000 determines that the dynamic security codes DCWi and DCW2 are equal (result of the test E40 positive), it sends the transaction data (step E50) to the bank server 6000 by replacing the dynamic security code DCCVi by the security code CW for verification of this code by the bank server 6000 .

In a fifth embodiment of the invention shown with reference to FIG. 8 in which it is not necessary to involve the bank server 6000, the server 5000 sends an authorization message directly to the server of the merchant site 3000. during a step E46 so that it delivers the goods or services corresponding to the user.

Detailed description of a sixth embodiment of the invention

In a particular embodiment of the invention, the security dynamic code verification server 5000 is also able to check the static security code CW associated with a PAN bank account. For this purpose, and as shown in FIG. 9, the server 5000 manages a table 5600 in which it stores, for each bank account number PAN, a verification mode "S / D" indicating whether the verification of a transaction must use the security code CW (mode "S") or the dynamic security code DCWi (mode "D"). The server 5000 stores in this table 5600, the dynamic security code CW at least for the microcircuit cards 1000 for which the verification mode is the static mode "S".

The S / D verification mode may be modified by the server 5000 upon receipt of a message from a security management server 7000 shown in FIG. 2.

In the embodiment described here, the holder of the microcircuit card 1000 can contact the security management server 7000 to ask him that the verification of his transactions, by default carried out using the dynamic security code DCCVi, uses the less for a while, the static security code CW. The user can make such a request especially when the display 1100 of the microcircuit card 1000 is out of use or when the battery of this card is insufficiently loaded.

It will be appreciated that in such circumstances, the user may also instruct the server 7000 to generate a limited life security code CW * as later described with reference to the seventh embodiment of the invention.

In the particular embodiment described here, the security management server 7000 has means for authenticating the user to take into account the change of verification mode and transmit it to the dynamic code verification server 5000. These authentication means may in particular use a password, a challenge mechanism or cryptographic functions.

In a particular embodiment, the user can, after authentication, communicate his static security code CW to the server 7000 so that it transmits it to the server 5000 for verifying dynamic security code.

In the particular embodiment described here, the verification mode is by default the verification mode "D" based on the dynamic security code DCCVi and the switchover in the static verification mode is only temporary. For this purpose, in the embodiment described here, the table 5600 includes a "TL" column in which the dynamic code verification server 5000 stores a criterion for determining whether the verification of the static code CW is still allowed.

This criterion may for example be a deadline provided to the server 5000 by the security management server 7000; such a date can also be calculated by the server 5000 from the date of receipt of the message from this server 7000.

Alternatively, the security dynamic code verification server 5000 may perform checks based on the security code CW: - until receiving a predetermined message from the security management server 7000; or - as long as a predetermined number of transactions has not been exceeded; or - as long as a cumulative total amount of transactions has not been reached.

Figure 10 illustrates in flowchart form a method implemented by the security dynamic code verification server 5000 in this embodiment.

During a step G10, the server 5000 initializes the verification mode to the dynamic mode "D" for all PAN bank accounts.

If the server 5000 receives (step G20) a message MSG from the server 7000 for a PAN account, it switches the verification mode to static mode.

In this example the static security code CW for this PAN account is communicated to the server 5000 in the MSG message.

Alternatively, the server 5000 calculates the static security code CW as previously described using its module 5800 using the bank account number PAN of the card, its expiration date EXP and a secret key using a cryptographic algorithm.

The table 5600 is updated with the static security code received from the server 7000 or calculated by the server 5000 and with the criterion TL making it possible to determine whether the verification based on the static code is authorized.

As mentioned previously, this criterion can be constituted by a duration received from the server 7000 or linked to the reception of a message from the server 7000 to switch back to the dynamic mode "D", a cumulative total amount or maximum number of authorized transactions.

If during a step G30, the server 5000 is requested to verify a transaction for a bank account PAN, it checks in the table 5600 (step G40), if the verification mode for this account PAN is the static mode "S And the TL criterion for performing checks on the basis of the security code CW is verified.

If these two conditions are met, the security dynamic code verification server 5000 checks the transaction on the basis of the security code CW stored in the table 5600 (step G50).

Otherwise, the server 5000 calculates a dynamic security code DCCV2 and verifies the transaction on the basis of this dynamic security code (step G60). If successful, and according to the embodiment of the invention, the server 5000: - sends a message directly to the server 3000 of the merchant site to validate the transaction; or - transmits the transaction data after replacing the dynamic security code DCCVi by with the security code CW to the security server 6000.

In this embodiment, the architectures described in FIGS. 2, 4, 6 and 7 may be used: the security dynamic code verification server 5000 may or may not be associated with an interface module 5500, each of the entities 5000 and 5500 possibly being implemented in the bank server 6000.

Detailed description of a seventh embodiment of the invention

In a particular embodiment, and as shown in FIG. 11, the security dynamic code verification server 5000 stores in a table 5700, at least for certain PAN bank accounts, a limited duration security code CW *, and in association with this code, a TL criterion for determining until when this security code CW * can be validly used.

This TL lifetime criterion can be: - a maximum number of transactions; - associated with a cumulative maximum amount of transactions; or - a deadline for use.

In the embodiment described here, the holder of the microcircuit card 1000 can contact the security management server 7000 to ask him, after authentication, to generate a lifetime security code CW * with a limited lifetime by means of a cryptographic key for example.

The generation of the limited-life security code CW * may possibly require interaction with the holder of the microcircuit card 1000, by means of his terminal via a website or by a voice server for example.

The lifetime limited security code CW * is then communicated to the holder of the microcircuit card 1000, for example by a voice server, by SMS, by email or via a Web interface of this server 7000 displayed on the screen. of the user terminal 2000.

In a particular embodiment, the user terminal 2000 has an application and a module capable of communicating the lifetime limited security code CW * to near-field communication means of the microcircuit card 1000 and the code CW * is presented to the user on the 1100 screen of the card. The card may optionally use a button to enable the establishment of this near-field communication.

With reference to FIG. 12, this limited life security code CW * can be received by the security dynamic code verification server 5000 of the server 7000 7000 during a step H10.

In the embodiment described here, the security dynamic code verification server 5000 obtains the lifetime information TL during a step H20. In practice, this information can be calculated by the server 5000 or by the security management server 7000, preferably from calculation rules specific to the holder of the microcircuit card 1000 and stored by the server 7000.

When the security dynamic code verification server 5000 is requested to verify a transaction (step H30), it begins, in this embodiment, to generate a dynamic security code DCCV2 (step H40) and to check whether the security code CS received in the transaction data is identical to this code (step H50).

If this is the case, depending on the embodiment of the invention, the server 5000 (step H60): sends a message directly to the server 3000 of the merchant site to validate the transaction; or - transmits the transaction data to the bank server 6000 after replacing the dynamic security code CS with the static security code CW of the card 1000.

When the dynamic security code DCCV2 calculated in step H40 is different from the security code CS included in the transaction data, the server 5000 checks (step H70) whether this security code corresponds to the security code CW * duration limited life for this PAN account and, depending on the TL parameter, whether this code is still valid. Of course, it is possible to start by checking in step H50 whether the security code CS corresponds to the security code CW * with limited lifetime, and if it is not the case, in step H70 if if the security code CS corresponds to the dynamic security code DCCV2 generated in step H40.

Be that as it may, in case of success of this double check, the server 5000 executes the step H60 previously described to authorize the transaction, either directly or indirectly.

Otherwise, the dynamic security code verification server 5000 sends (step H80) a message to the server 3000 of the merchant site to refuse the transaction. Alternatively, and as mentioned previously, the verification server 5000 may send the bank server 6000 modified transaction data DT (£ YY) with a false security code CW false to trigger the refusal of the transaction by the bank server. The use of a lifetime limited security code CW * may in particular allow the holder of the microcircuit card 1000 to lend his card for a limited time, a number of transactions or a maximum amount of transactions.

As in the other embodiments, the architectures described in FIGS. 2, 4, 6 and 7 may be used: the security dynamic code verification server 5000 may or may not be associated with an interface module 5500, each of the entities 5000 and 5500 can possibly be implemented in the bank server 6000.

Possible Variants Common to All Embodiments The invention has been described above in the particular context of an online payment application. It can apply: - for other financial applications; but also - in others when it is a matter of verifying a security code entered by a user for example to check an identification document number, a social security identifier, a security code. door opening, an access code to a website.

In the previously described embodiments, the generation of the dynamic security code DCWi by the card and the dynamic security code DCCV2 use a time parameter. Those skilled in the art will understand that these time parameters must be synchronized to allow the comparison of these codes. In practice, to overcome these synchronization problems, the server can generate several second security codes using different temporal parameters, a transaction being authorized when one of these second security codes corresponds to the dynamic security code received from the microcircuit card.

Alternatively, the time parameter can be replaced by an incremented counter: - on the microcircuit card side 1000 each time the card generates a new dynamic security code, for example when the user presses the push button 1400; and on the side of the security dynamic code verification server 5000, each time that the latter generates a dynamic security code for its part to check the validity of a dynamic security code generated by the microcircuit card 1000. again, those skilled in the art will understand that these counters must be synchronized to allow the comparison of these codes. In practice, in order to overcome these synchronization problems, the server can generate several second security codes by using different counter values, a transaction being authorized when one of these second security codes corresponds to the dynamic security code received. of the microcircuit card. References: [REFAA]: European Patent Application No. EP 2 568 448 published on March 13, 2013 for a "credit or debit card with a security code".

[REFCW]: en.wikipedia.org/wiki/card_security_code [REFPAN]: en.wikipedia.org/wiki/Bank_card_number

Claims (15)

A dynamic security code verification server (5000) comprising: a communication module (5200) capable of receiving bank transaction data (DT (DCCVi)) comprising an identifier (PAN) and a first dynamic security code; (DCCVi) generated by a device (1000) associated with this identifier from a time data or a counter of the number of first dynamic security codes (DCCVi) generated by said device (1000); a module (5300) for generating a second dynamic security code (DCCV2) from said identifier (PAN) and a time data or a counter for the number of second dynamic safety codes (DCCV2) generated by said module (5300) for said identifier (PAN); a module (5400) for comparing the first and second dynamic safety codes; said communication module (5200) being able to send to a server (6000), and only in case of equality of the first and second dynamic codes (DCCVi, DCCV2), said transaction data in which said dynamic security code (DCCVi) is replaced by a security code (CW) associated with said device (1000), said server (6000) being configured to check the validity of said security code (CW) to allow or deny said transaction. The dynamic security code verification server (5000) according to claim 1, characterized in that said server is configured to send a refusal message of said transaction to a server configured to perform the transaction (3000) if said first and second dynamic codes (DCCVi, DCCV2) are different. 3. Interface module (5500) capable of receiving transaction data comprising either a security code (CW) or a dynamic security code (DCWi) and transmitting said transaction data: - to a server (5000) dynamic security code verification method according to claim 1 or 2 if said transaction data comprises a dynamic security code (DCWi); or - a server (6000) configured to check the validity of the security code (CW) to allow or deny said transaction if said transaction data comprises a security code (CW). A system (10) for verifying a security code comprising: - a security dynamic code verification server (5000) according to any of claims 1 to 3; a server (6000) configured to check the validity of said security code (CW) to allow or refuse said transaction; and an interface module (5500) according to claim 3. The system of claim 4 wherein said security dynamic code verification server (5000) is implemented in said server (6000) configured to verify the validity of said security code (CW). The system of claim 5 wherein said interface module (5500) is implemented in said server (6000) configured to verify the validity of said security code (CW). 7. System according to any one of claims 4 to 6 characterized in that it comprises: - a microcircuit card (1000) comprising a static security code (CW) and a screen (1400) for displaying a dynamic code security card (DCCVi) generated by said card for performing a transaction; said security dynamic code verification server (5000) being able to check the validity of said dynamic security code (DCCVi) generated by said card; said server (6000) configured to check the validity of said static security code (CW) being able to verify the validity of said security code (CCV) of said card to allow or refuse said transaction. 8. System according to claim 7 characterized in that it comprises: - a terminal (2000) allowing a user to connect to a server (3000) to perform said transaction, said terminal (2000) having a human-machine interface enabling said user to enter the data of said transaction including said dynamic security code (DCCVi) generated by said card for this transaction; said server (3000) for performing the transaction being able to transmit said transaction data to said dynamic security code verification server (5000) according to the ISO 8583 protocol. 9. A method for verifying a dynamic security code comprising: a bank transaction data reception step (E20) (DT (DCCVi)) comprising an identifier (PAN) and a first dynamic security code (DCCVi) generated; by a device (1000) associated with this identifier from a time data or a counter of the number of first dynamic safety codes (DCCVi) generated by said device (1000); a step (E30) for generating a second dynamic security code (DCCV2) from said identifier (PAN) and a time data or a counter of the number of second dynamic safety codes (DCCV2) generated by said module (5300) for said identifier (PAN); a step (E40) for comparing the first and second dynamic safety codes; a step (E50) of sending to a server (6000), and only in case of equality of the first and second dynamic codes (DCCVi, DCCV2), said transaction data in which said dynamic security code (DCCVi) is replaced by a security code (CW) associated with said device (1000), said server (6000) being configured to check the validity of said security code (CW) to allow or deny said transaction. 10. Server (5000) for dynamic security code verification: - a communication module (5200) capable of receiving, in a communication network (4000), transaction data (DT (DCCVi)) including an identifier (PAN ) and a first dynamic security code (DCCVi) generated by a device (1000) associated with this identifier from a time data or a counter of the number of first dynamic security codes (DCCVi) generated by said device ( 1000), said transaction data being for a server (6000) configured to check the validity of a security code (CW) to allow or deny said transaction; a module (5300) for generating a second dynamic security code (DCCV2) from said identifier (PAN) and a time data or a counter for the number of second dynamic safety codes (DCCV2) generated by said module (5300) for said identifier (PAN); a module (5400) for comparing the first and second dynamic safety codes; said communication module (5200) being able to send to a server (3000) capable of carrying out said transaction, and only in case of equality of the first and second dynamic codes (DCCVi, DCCV2), an authorization message for performing said transaction, said security dynamic code verification server (5000) being implemented in an interface equipment (5000) between said network (4000) and said server (6000) configured to check the validity of a static code of security (CW). 11. System (10) for verifying a security code comprising: - a microcircuit card (1000) comprising a security code (CW) and a screen (1400) for displaying a dynamic security code (DCCVi) generated by said card to perform a transaction; a security dynamic code verification server (5000) according to claim 10 able to verify the validity of said dynamic security code (DCCVi) generated by said card and to send an authorization message of said transaction to a server (3000 ) able to perform said transaction, only when the validity of said dynamic code has been verified. 12. System according to claim 11 characterized in that it comprises: - a terminal (2000) allowing a user to connect to said server (3000) to perform said transaction, said terminal (2000) having a man-machine interface allowing user audit to enter the data of said transaction including said dynamic security code (DCCVi) generated by said card for this transaction; said server (3000) for performing the transaction being able to transmit said transaction data to said security dynamic code verification server (5000) according to the ISO 8583 protocol and to receive according to this protocol an authorization message of said transaction in accordance with from this server (5000). 13. A dynamic security code verification method comprising: - a step (E20) for receiving, in a communication network (4000), transaction data (DT (DCCVi)) comprising an identifier (PAN) and a first code; security dynamic (DCCVi) generated by a device (1000) associated with this identifier from a time data or a counter of the number of first dynamic security codes (DCCVi) generated by said device (1000), said data transaction method for a server (6000) configured to check the validity of a security code (CW) to allow or deny said transaction; a step (E30) for generating a second dynamic security code (DCCV2) from said identifier (PAN) and a time data or a counter of the number of second dynamic safety codes (DCCV2) generated by said module (5300) for said identifier (PAN); a step (E40) for comparing the first and second dynamic safety codes; a sending step (E46) to a server (3000) capable of carrying out said transaction, and only if the first and second dynamic codes (DCCVi, DCCV2) are equal, an authorization message for performing said transaction, said method being implemented in an interface equipment (5000) between said network (4000) and said server (6000) configured to check the validity of a security code (CW). A computer program comprising instructions for implementing the steps of a dynamic security code verification method according to claim 9 or 13 when the program is executed by a computer. 15. A computer-readable recording medium on which a computer program is recorded including instructions for performing the steps of the dynamic security code verification method according to claim 9 or 13.