FR2856497A1 - Virtual prepaid card usage code determining process, involves selecting user number associated with selected serial number, and using selected user number during certificate generation time, to determine specific usage - Google Patents

Abstract

The process involves selecting a serial number and generating a certificate from the serial number. The serial number and the certificate are scrambled for delivering a usage code. A user number associated to the serial number is selected. The user number is used at the time of generation of the certificate and/or scrambling process, to determine a specific usage for each user number associated to a same serial number. An independent claim is also included for a system for managing a virtual prepaid card.

Description

The present invention relates to a method for determining a

  code for using a virtual prepaid card type card as well as a method for verifying such a code and a virtual prepaid card management system.

  Today there are virtual prepaid card services allowing a user to receive or access a service from a service provider, this service being paid in advance when purchasing a card and the corresponding credit being managed by an equipment of the network.

  Thus, unlike physically prepaid cards which directly include modifiable credit information, virtual prepaid cards include a non-modifiable use code and allow authentication and access to a remote user account.

  Prepaid virtual cards are for example immaterial and consist of a simple number appearing for example on a scratch card, or else, material and consist of a physical device emitting for example signals of DTMF type (Dual Tone Multi Functions) .

  Such virtual prepaid cards each conventionally comprise a unique use code which allows access to a user account associated with this card and managed for example by a remote server ac20 transferable through a telecommunications network.

  Conventionally, these usage codes are determined and verified independently of the services associated with the virtual prepaid card, as described below.

  For determining a usage code, one of a plurality of available serial numbers is selected. This serial number is then used by a certificate generation algorithm, so as to obtain a certificate.

  The certificate and the serial number are then scrambled so as to form the use code consisting of a numerical value allowing access control to a service.

  During use, the code is received and then descrambled to obtain the serial number and a first probationary certificate. The serial number obtained is again used by the same algorithm for generating certificates as that used when determining the code, so as to obtain a second probationary certificate.

  The first and second probationary certificates are then compared with each other, their identity corresponding to a positive verification of the code of use.

  The determination and verification of the use codes are carried out automatically, for example by computers, and advantageously, in secure environments in order to reduce the risks of hacking.

  The prepaid accounts subject to the use of vir10 tuelles prepaid cards are each associated with a unique serial number, so that the methods of determining and verifying existing use codes only allow the association of an account. 'with a single use code.

  In fact, virtual prepaid card management systems cannot manage several users of the same prepaid account, thereby significantly reducing the user-friendliness of their implementation by requiring the creation of a different account for each user.

  The object of the present invention is to solve this problem by defining a method for determining the use code, a method for verifying the use code, and a management system for virtual prepaid cards 20 allowing the management of several users for the same prepaid account.

  The subject of the present invention is a method for determining a code for using a card of the virtual prepaid card type comprising at least the implementation of the following steps: - a step of selecting a serial number from a plurality of 25 serial numbers available; a step for generating a certificate implementing a certificate generation algorithm applied at least to said selected serial number to issue a certificate; and - a scrambling step implementing a scrambling em30 algorithm applied to said selected serial number and to said certificate to deliver a use code, characterized in that said method further comprises a step of selecting a number user among a plurality of user numbers associated with said selected serial number and in that said selected user number is used during said step of generating a certificate and / or said scrambling step in order to determine a specific use code for each user number associated with the same serial number.

  According to other characteristics of the method of the invention: - said selected user number is used only during said step of generating a certificate to issue a certificate specific to said user number selected by the application of said algorithm generation of certificates to said selected serial number and to said user number; said user number is used only during said scrambling step to deliver said use code by applying said scrambling algorithm to said selected serial number, said certificate and said user number; said user number is used during said step of generating a certificate to issue a certificate specific to said user number by applying said algorithm for generating certificates to said selected serial number and to said user number selected, and during said scrambling step for delivering said usage code by applying said scrambling algorithm to said selected serial number, said certificate and said user number.

  The invention also relates to a method for verifying a code for using a card of the virtual prepaid card type, comprising the implementation of the following steps: a step of receiving a code for using a virtual prepaid card; a step of descrambling said code to issue at least one serial number and a first probationary certificate, included in said use code; a step for generating a certificate implementing a certificate generation algorithm applied at least to said serial number to issue a second probationary certificate; and a step of comparing said first and second probationary certificates, their identity corresponding to a positive verification of said use code, characterized in that said method comprises, in the event of positive verification, the determination of a user number from a plurality of user numbers associated with said serial number.

  According to other characteristics of this method: - said determination comprises the repetition of said step of generating a certificate implementing said algorithm for generating certificates applied to said serial number as descrambled and in turn to each of a plurality of user numbers associated with said serial number to form a second probationary certificate for each of said user numbers, and repeating said step of comparing the first and second probationary certificates until the comparison is positive or that all second probative certificates have been tested; said determination comprises said descrambling step adapted to implement said descrambling algorithm applied to said use code in order to issue said serial number, said first probationary certificate and said user number; - Said determination includes said descrambling step adapted to implement said descrambling algorithm applied to said use code to issue said serial number, said first proba20 certificate and said user number, and said step of generating a certificate adapted to implement said certificate generation algorithm applied to said descrambled serial number as well as said descrambled user number, in order to issue a second probationary certificate specific to said user number; - It further includes a step of comparing said determined user number with a predetermined list of authorized user numbers for said determined serial number.

  Finally, the invention relates to a system for managing virtual prepaid cards comprising means for determining codes for using virtual prepaid cards, means for verifying such codes and means for managing user accounts associated with said codes, characterized in that said means for determining use codes are adapted to deliver a specific use code for each of a plurality of user numbers associated with the same serial number, in that said means for checking are adapted to determine a serial number and an associated user number for each code verified positively, and in that said means for managing user accounts of virtual prepaid cards are adapted to manage, for each user account identified by the same 5 serial number, a plurality of different users identified by user numbers.

  The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the appended drawings, in which: - Figs. la and lb represent a first embodiment respectively of a method for determining and verifying a code according to the invention; - Figs. 2a and 2b show a second embodiment respectively of a method for determining and verifying a code according to the invention - Figs. 3a and 3b show a third embodiment respectively of a method for determining and verifying a code according to the invention; and - Fig.4 shows a block diagram of a management system 20 of virtual prepaid cards implementing the method of the invention.

  It is considered in the following description, that the methods for determining and verifying a code described below, are implemented automatically by equipment such as computers, computer servers or the like.

  In addition, it is considered that these methods are implemented in secure environments, such as servers computer protected against hacking.

  Referring to Figure la, we will now describe a first embodiment of a method for determining a code according to the invention.

  This method begins with a step 2 of selecting a serial number denoted NS, from among a plurality of serial numbers available for determining a use code. For example, the NS serial numbers are established arbitrarily or in order of creation of the associated user accounts and are selected automatically and successively, by scanning a database.

  This step 2 for selecting the serial number NS is followed by a step 4 for selecting a user number, denoted NU, from among a plurality of 5 user numbers associated with the serial number NS previously selected.

  The user number NU and the serial number NS are then used during a step 6 of generating a certificate implemented by the application of a determined algorithm for generating certificates making it possible to issue a CRT certificate. .

  For example, the certificate generation algorithm is a non-reversible condensation algorithm, such as the so-called SHA1 algorithm (in English: "Standard Hash Algorithm") or even MD5 allowing to retain only a few determined parts of the number (s). supplied as input.

  The CRT certificate is therefore specific to both the NS serial number and the NU user number.

  Finally, the CRT certificate and the serial number NS are used during a scrambling step 8 implemented by the application of a determined scrambling algorithm making it possible to issue a use code noted CODE.

  For example, the scrambling algorithm used is a reversible permutation algorithm.

  It therefore appears that in this first embodiment of the determination method, the use number NU is used only during step 6 of generating a certificate for determining the CRT certificate.

  In addition, the user number NU being taken into account only at the level of step 6 delivering a CRT certificate of invariant size, the use code CODE has the advantage of having the same size as in the state-of-the-art technique, thus increasing the user-friendliness and portability of the invention.

  Referring to Figure 1b, we will now describe a first embodiment of the method for verifying a code for using the invention.

  This verification process begins with a step 10 of receiving the use code CODE.

  Step 10 is followed by a descrambling step 12 implementing a descrambling algorithm corresponding to the inverse of the scrambling algorithm used during step 8 as described with reference to FIG.

  This descrambling step 12 thus makes it possible to issue the serial number NS of the card as well as a first probationary certificate noted CRT1.

  The method then comprises a step 14 for generating a certificate implemented by the application of the same algorithm for generating certificates as that used in step 6 as described with reference to FIG. La.

  This certificate generation algorithm is applied to the serial number NS as delivered by the descrambling step 12, as well as, in turn, with each of a plurality of user numbers denoted NU1 to form a second certificate evidence, noted CRT21, for each user number NU1.

  The method then comprises a step 16 of comparison between the first probationary certificate CRT1 and each of the second probationary certificates CRT2i.

  If a comparison carried out in step 16 is positive, that is to say that the first and the second probative certificates CRT1 and CRT2i are identical, the process is completed. The use code CODE is thus validated, as is the user number NU1 used to determine during step 14, the second probationary certificate CRT2j equal to the first probationary certificate CRT1.

  The determination of the user number NU thus allows the identification of a specific user among a plurality of users associated with the same user account corresponding to the serial number NS.

  In the case where the comparison step 16 is negative, steps 14 and 16 are repeated with another user number NU1 of the plurality of user numbers associated with the serial number NS.

  The repetition of steps 14 and 16 is continued until the comparison of step 16 is positive or until all the second probative certificates that it is possible to obtain with the plurality of user numbers NU1 associated with the number NS series, have been tested.

  Such repetition thus forms a determination of the user number NU included in the received use code CODE.

  This embodiment has the advantage of using the user number NU at the level of the application of the algorithm for generating certificates, which allows significant security in terms of differentiation between the different user numbers. NUs associated with the same NS serial number.

  However, this method has the disadvantage of having to make an exhaustive verification of all the possible user numbers, which requires time and computing resources.

  Referring to Figures 2a and 2b, we will now describe a second embodiment of the invention.

  The determination method shown in FIG. 2a begins as before, with step 2 of selecting a serial number NS 10 from a plurality of serial numbers.

  This method also includes step 4 of selecting a user number NU from a plurality of user numbers associated with the serial number NS.

  In parallel with this step 4, the method includes a step 20 of generating a certificate implementing a certificate generation algorithm applied to the single serial number NS in order to issue the CRT certificate.

  The method finally comprises a scrambling step 22 implementing a scrambling algorithm applied to the selected serial number NS, to the selected user number NU and to the CRT certificate issued at the end of step 20.

  These three elements are confused during step 22 in order to form a use code CODE which contains them entirely.

  Referring to Figure 2b, we will now describe the verification method corresponding to this second embodiment.

  This process begins, as before, with step 10 of receiving the use code CODE.

  It then includes a descrambling step 30 implementing the inverse algorithm to that used during step 22 as described with reference to FIG. 2a, and making it possible to output the serial number NS, the number d user and a first CRT1 probationary certificate.

  Step 30 followed by a step 32 for generating a certificate implementing the same algorithm for generating certificates as that used in step 20 described with reference to FIG. 2a and applied to the only serial number NS in order to issue a second CRT2 probationary certificate.

  Finally, the method comprises a comparison step 34 making it possible to compare whether the first and second probative certificates CRT1 and CRT2 are identical.

  In the case where the comparison step 34 is positive, the use code CODE is validated and the user number NU is determined.

  Such an embodiment has the advantage of being economical in terms of calculations to be performed, in particular by limiting the number of implementations of the certificate generation algorithm.

  However, this embodiment has low security, the user number NU being used only during the scrambling step 22.

  This scrambling can be reversed to directly obtain the user number NU, the security of this embodiment essentially lies in the confidentiality of the algorithms used.

  In addition, in such an embodiment, the code of use CODE 15 is extended compared to the techniques of the state of the art since it must contain the entire NS serial number, the CRT certificate and the number d NU user.

  Referring to Figures 3a and 3b, we will now describe a third embodiment of the invention.

  The method for determining a use code shown with reference to FIG. 3a begins, as previously, with step 2 of selecting a serial number NS from a plurality of available serial numbers.

  Step 2 is followed by step 4 of selecting a user number 25 NU from a plurality of user numbers associated with the selected serial number NS.

  The method then comprises a step 40 of generating a certificate implementing a certificate generation algorithm applied to both the selected serial number NS and the user number NU in order to issue a CRT certificate.

  Finally, the method comprises a scrambling step 42 implementing a scrambling algorithm applied to the serial number NS, to the selected user number NU and to the certificate CRT in order to issue the use code CODE.

  As previously, in this embodiment, the size of the use code CODE is extended, this one having to contain entirely the serial number NS, the user number NU and the certificate CRT.

  This code is checked during the process described with reference to FIG. 3b which begins with step 10 of reception.

  The method then includes a descrambling step 50 implementing a descrambling algorithm corresponding to the inverse of that used during step 42 described with reference to FIG. 3a.

  This step 50 makes it possible to obtain the serial number NS, the user number NU as well as a first probationary certificate CRT1.

  Step 50 is followed by a step 52 for generating a certificate implementing the same algorithm for generating certificates as that used in step 40 described with reference to FIG. 3a, and applied to the serial number NS and the user number NU as delivered at the end of step 50.

  This step 52 thus makes it possible to obtain a second probationary certificate CRT2.

  The method finally comprises a step 54 of comparison of the first and second probative certificates CRT1 and CRT2 which, if it is positive, makes it possible to validate the use code CODE as well as the user number NU.

  This embodiment is economical in terms of calculations since the algorithm for generating certificates is only implemented once in each process. In addition, this embodiment presents a very important security, the user number being used at the level of the generation of the certificate as well as at the level of scrambling.

  However, in this embodiment, the use code CODE is of a larger size than in the state of the art since it must also integrate the user number NU at the time of scrambling.

  Advantageously, the verification methods described include a step of comparing the user number determined with respect to an exhaustive list of user numbers possible for the determined serial number.

  It therefore generally appears that the methods of determining a code as described allow a user number selected during a step of generating a certificate and / or scrambling to be used to issue a code. of specific use for each user number associated with the same serial number.

  Correspondingly, the methods for verifying a use code as described allow, in the event of a positive verification of the use code, the determination of a user number from among a plurality associated with the same number. series.

  Such methods of determining and verifying a code can be implemented in a virtual prepaid card management system such as that described with reference to FIG. 4.

  This system includes means 60 for determining use codes comprising, for example, a database 62 in which all the serial numbers NS are stored as well as the associated NU user numbers, this database 62 being linked to a computer 64 formed for example of a computer server suitable for implementing the method for determining a use code according to the invention, such as for example one of the three embodiments described with reference to FIGS. , 2a and 3a.

  Advantageously, the means 60 for determining usage codes are connected to means for manufacturing support cards intended each to receive a usage code and then to be sold to users.

  Such a card provided with its use code CODE is represented by the reference numeral 66.

  The system also includes means 68 for verifying use codes linked on the one hand to means 70 for managing user accounts and on the other hand, to an information transfer network 72, such as by 25 example the switched telephone network called PSTN.

  For example, the means 68 are formed of a computer server or else of a program comprising code instructions for its execution by such a server.

  Likewise, the means 70 are conventionally formed of a database 74 connected to a computer server 76 for managing the database.

  In operation, the means 60 determine a use code CODE associated with the card 66. This card 66 is then made available to a user who enters the use code CODE of the prepaid card 66 and transmits it by conventional means of communication through network 72, to means 68 of verification.

  On reception, the verification means 68 implement a method according to the invention, such as for example one of the embodiments described 5 with reference to FIGS. 1b, 2b or 3b, in order to determine whether the use code CODE is valid and, in this case, allow the determination of an associated user number.

  The serial number thus makes it possible to identify a user account and, thanks to the methods of the invention, this user account can be shared between several users, each identified separately by means of the user number. This allows separate processing of the different users of the same account by the means 70 for managing user accounts, which processing is carried out in a conventional manner.

  Advantageously, the means 64 for determining codes and the means 68 for verifying codes, are linked or even integrated in the same element in order to ensure that the same algorithms for generating certificates, scrambling and descrambling are used. or in order to be able to access the database 62 comprising the serial numbers and the associated user numbers.

  It therefore appears that such a system makes it possible to manage several users on the same virtual prepaid card account by differentiating them by their single use code.

Claims (10)

  1. Method for determining a code for using a card of the virtual prepaid card type (66) comprising at least the implementation of the following steps: - a step (2) for selecting a serial number ( NS) from a plurality of available serial numbers; - a step (6; 20; 40) of generating a certificate implementing a certificate generation algorithm applied at least to said selected serial number (NS) to issue a certificate (CRT); and - a scrambling step (8; 22; 42) implementing a scrambling algorithm applied to said selected serial number (NS) and to said certificate (CRT) to deliver a use code (CODE), characterized in that said method further comprises a step (4) of selecting a user number (NU) from among a plurality of user numbers associated with said selected serial number (NS) and in that said number selected user (NU) is used during said step (6; 20; 40) of generating a certificate and / or said scrambling step (8; 22; 42) in order to determine a use code (CODE ) specific for each user number (NU) associated with the same serial number (NS).   2. Method according to claim 1, characterized in that said selected user number (NU) is used only during said step (6) of generating a certificate to issue a certificate (CRT) specific to said user number selected (NU) by applying said certificate generation algorithm to said selected serial number (NS) and said user number 25 (NU).   3. Method according to claim 1, characterized in that said user number (NU) is used only during said scrambling step (22) to deliver said use code (CODE) by the application of said algorithm d 'scrambling to said selected serial number (NS), to said certificate (CRT) and to said said user number (NU).   4. Method according to claim 1, characterized in that said user number is used during said step (40) of generating a certificate to issue a certificate (CRT) specific to said user number (NU) by l application of said algorithm for generating certificates to said selected serial number (NS) and to said selected user number (NU), and during said scrambling step (42) to deliver said use code (CODE) by application of said scrambling algorithm to said selected serial number (NS), to said certificate (CRT) and to said user number (NU).   5. Method for verifying a use code (CODE) of a card of the virtual prepaid card type (66) comprising the implementation of the following steps: - a step (10) of receiving a code for use (CODE) of a virtual prepaid card (66); - a step (12; 30; 50) of descrambling said code (CODE) to issue at least one serial number (NS) and a first probationary certificate (CRT1), included in said use code (CODE); a step (14; 32; 52) of generating a certificate implementing a certificate generation algorithm applied at least to said serial number (NS) to issue a second probationary certificate (CRT2; CRT2i); and - a step (16; 34; 54) of comparing said first and second probationary certificates (CRT1, CRT2; CRT2j), their identity corresponding to a positive verification of said use code (CODE), characterized in that said method comprises , in case of positive verification, the determination of a user number (NU) among a plurality of user numbers associated with said serial number (NS).   6. Method according to claim 5, characterized in that said determination comprises repeating said step (14) of generating a certificate implementing said algorithm for generating certificates applied to said serial number (NS) as descrambled and in turn to each of a plurality of user numbers (NU1) associated with said serial number (NS) to form a second probationary certificate (CRT2i) for each of said user numbers (NUe), and the repetition of said step (16) of comparison between the first and the second probative certificates (CRT1, CRT21) until the comparison is positive or all the second probative certificates (CRT2i) have been tested.   7. Method according to claim 5, characterized in that said determination comprises said descrambling step (30) adapted to implement said descrambling algorithm applied to said use code (CODE) in order to issue said serial number (NS) , said first probationary certificate (CRT1) and said user number (NU).   8. Method according to claim 5, characterized in that said determination comprises said descrambling step (50) adapted to implement said descrambling algorithm applied to said use code (CODE) to issue said serial number (NS) , said first probationary certificate (CRT1) and said user number (NU), and said step (52) of generating a certificate adapted to implement said algorithm for generating certificates applied to said unscrambled serial number (NS) as well as audit nu10 descrambled user number (NU), in order to issue a second probationary certificate (CRT2) specific to said user number (NU).   9. Method according to any one of claims 5 to 8, characterized in that it further comprises a step of comparing said determined user number (NU) with respect to a predetermined list of user numbers (NU) ) authorized for said specified serial number (NS).   10. System for managing virtual prepaid cards comprising means (60) for determining codes of use (CODE) for virtual prepaid cards (66), means (68) for verifying such codes (CODE) and means ( 70) for managing user accounts associated with said codes 20 (CODE), characterized in that said means (60) for determining use codes are adapted to deliver a specific use code (CODE) for each of a plurality of user numbers (NU) associated with the same serial number (NS), in that said verification means (68) are adapted to determine a serial number (NS) and a user number (NU) ) associated 25 for each code (CODE) verified positively, and in that said means (70) for managing user accounts of virtual prepaid cards (66) are adapted to manage, for each user account identified by the same number of series (NS), a plurali different users identified by user numbers (NU).