Person identification control method and system for implementing same

The invention relates to a person identification control method and to a system for implementing same. The inventive method comprises the following steps consisting in: detecting biometric data (23, 48, 79, 94, 108) relating to at least one person; seeking a concordance between the biometric data relating to the person and biometric data that have been pre-stored in a biometric database (26, 51, 83, 97, 110), said pre-stored biometric data relating to persons for whom identification means have already been generated; and, when no concordance is found, generating an identification means (29, 56, 84, 98, 103, 111) that is associated with the person from the biometric data relating to the person and at least one identity (24, 49, 80, 95, 117) for said person.

CROSS REFERENCE TO RELATED APPLICATION

This is the U.S. National Phase of International Application No. PCT/FR2005/00544, filed Mar. 7, 2005, the entire disclosure of which is incorporated by reference.

FIELD OF THE DISCLOSURE

The present invention relates to the identification control of persons. It relates more especially to the generation of a unique means of identification of persons.

BACKGROUND OF THE DISCLOSURE

An especially beneficial application of the invention, although not exclusive, consists in controlling the granting of entitlements to persons having obtained a unique means of identification.

The term “entitlement” is to be understood in its widest acceptance, the granting of an entitlement to a person being understood as the concrete realization of a possibility offered to this person. By way of example, a person may have a driving license, a building access badge, a transport pass be granted to them, or else be allocated a retirement fund, compensation or else a refund within the context of a social security system for example, etc.

The granting of such entitlements is confronted with a problem of uniqueness, in so far as one generally does not wish to grant the same entitlement to the same person several times.

Thus, certain current systems operate according to the following principle: a person wishing to have an entitlement granted to them firstly states their identity (for example their surname and forenames), then a check of this identity is performed with means that are generally limited and rather unreliable. Next, a check is made to verify whether the person bearing this identity has not already received the entitlement claimed, for example by consulting a database wherein are stored the identities of all the persons having already acquired the relevant entitlement. If the check shows that the person has not already acquired this entitlement, the latter is then granted to them and this information is taken into account in the database.

However, if the relevant person has usurped one or more identities, they can obtain the entitlement a number of times equal to the number of identities that they present to the system. The uniqueness of granting entitlements is not therefore ensured in such systems.

Furthermore, such systems grant entitlements in conjunction with the identity of the persons, so that they do not make it possible to grant entitlements to persons by virtue of their capacity, for example their membership of an association of anonymous individuals.

To limit these drawbacks and in particular to make the identification of persons more reliable, it is known to use biometric data associated with persons. The resulting principle is illustrated inFIGS. 1 and 2.

FIG. 1shows a prior phase of so-called enrollment, in the course of which a means of identification of a person is generated, this means of identification creating a tie between the biometric data of the person and their identity. Thus, the person1possesses a biometry3, that is to say biometric data characterizing them, such as fingerprints, characteristics of the iris of their eyes, etc. The person1states their identity4, which is then verified (step5). Next, an association is made between the biometry3and the identity4of the person1(step6). This association is finally stored on a means of identification associated with the person1. The means of identification is typically held by the person themselves, so that they alone possess a trace of the association between their biometry3and their identity4. Such a means of identification associated with a person is commonly called a biometric token. It may for example take the form of an identity card on which the fingerprints of the person have been affixed.

FIG. 2shows a subsequent phase of granting an entitlement. A person2claiming the granting of an entitlement must have been the subject of a prior enrollment according to the principles illustrated inFIG. 1. The biometry8of this person is then compared with that which was kept on the biometric token9associated with this person during their enrollment. If the biometries match (step10), it is then possible to retrieve the identity of the person2in a relatively reliable manner (step11) on the basis of the identity that they stated, for verification, during their enrollment, and which was stored on the biometric token9in association with the biometry8of this person. Thereafter, in step12, a check is made to verify whether the entitlement in question has already been obtained in relation to the identity retrieved. To do this, a search is performed for the presence of said identity in a database13storing the identities of the persons having acquired the entitlement in question. If the person2had not yet acquired the entitlement, the latter is finally granted to them in step14and this information is taken into account in the database13.

This mode of operation therefore improves the reliability of the identification of a person, since the identity stated by each person and verified during their enrollment is retrieved on the basis of this person's own biometric data and of the biometric token previously issued to this person.

However, it does not guarantee the uniqueness of the granting of entitlements. Specifically, a person possessing several biometric tokens, obtained during successive enrollments, may get an entitlement granted several times, with a different biometric token each time. This is especially true when the person obtains several biometric tokens with different identities for each token, this possibly occurring in particular when step5of verification of the identity is of low reliability.

A known and effective way of remedying this problem consists in storing, in a centralized database, an association between the biometry and the identity of each person.FIG. 3illustrates a phase of enrollment in accordance with this mode of operation. The person15possesses a biometry16and states an identity17which is verified by a check in step18. In step19a check is made to verify whether a biometric token has already been allocated to the person15by searching for the presence of the stated identity17in the database20of the identities storing the biometry/identity pairs of the persons for which a biometric token has already been generated. If the person15did not yet have a biometric token, one is then generated for them in step21, thereby guaranteeing that a single biometric token is generated for each person. The database20is finally updated to take account of the generation of the new token.

Subsequently, an entitlement can be granted as in the case illustrated inFIG. 2, if need be.

However, the mode of operation illustrated inFIG. 3requires that biometric data and identities of persons be placed in correspondence in a database20. Such a correspondence is rather undesirable since it could be used for purposes other than the simple granting of entitlements and thus run counter to individual freedom. It would even be contrary to legal provisions in respect of the protection of individual freedom in certain countries.

An object of the present invention is to limit the abovementioned drawbacks, by permitting an identification of persons which does not impede individual freedom.

Another object of the invention is to improve the reliability of the uniqueness of the means of identification associated with persons, with a view for example to affording control of the granting of entitlements to these persons, without thereby creating a database linking for each person, their biometry and their identity.

Another object of the invention is to limit the possibilities of fraud during the granting of entitlements.

Yet another object of the invention is to allow control of the granting of entitlements to persons without consideration of their identity.

SUMMARY OF THE DISCLOSURE

The invention thus proposes a method of identification control of persons, comprising a phase of generating a unique means of identification associated with at least one person comprising the following steps:

/a/ detecting biometric data relating to said person;

/b/ searching for a match between the biometric data relating to said person and biometric data previously stored in a biometric database, said previously stored biometric data relating to persons for which means of identification have been previously generated; and, when no match has been found:
/c/ generating a means of identification associated with said person from biometric data relating to said person and at least one identity of said person.

Step /b/ of the method thus makes it possible to ensure that a means of identification, for example a biometric token, has not already been associated with the relevant person in the past. One thus limits the possibilities of the same person obtaining several means of identification.

According to an advantageous embodiment of the invention, the method furthermore comprises a second phase of granting at least one entitlement to said person, in which:

/e/ said person identifies themselves with the aid of the means of identification which has been previously associated therewith; and

/f/ said entitlement is granted to said person when said entitlement has not already been granted to said person a number of times equal to a predetermined number.

The granting of entitlements being subject to identification of the person on the basis of the unique means of identification previously generated for said person, the person is thus prevented from being able to have entitlements granted several times by identifying themselves on the basis of distinct means of identification.

The phases of the method are applied to at least one person, that is to say a biometric token is associated with a given person or with a group of given persons. Likewise, the entitlement or entitlements are granted to a given person or to a group of given persons.

In a particular embodiment of the invention, a check of the identity of the person is performed before step /b/.

The granting of the entitlement is performed on the basis of an identifier, which may be the identity of said person or else an identifier of the biometric token which has been associated therewith (anonymous mode).

In a particular embodiment of the invention, the identifier of a biometric token is revoked before generating another one for the same person or the same group of persons. This may for example occur when the person claims to have lost his first biometric token. One thus advantageously prevents the multiple generations of tokens for one and the same person or one and the same group of persons, possibly giving rise to multiple grantings of entitlements fox these persons.

In particular embodiments of the invention, a key is calculated for each person, then associated with the identity thereof. It may for example be a biometric key which is calculated on the basis of biometric elements of the person, but is weakly discriminating so that the person cannot easily be retrieved on the basis of their key. This key may also be generated randomly, in which case it is moreover associated with the biometry of the relevant person.

The invention furthermore proposes a system, comprising means for implementing the abovementioned method.

When only the first phase of the method is implemented, the system may then be likened to a device.

When, on the other hand, the method comprises the first phase of generating a unique means of identification associated with at least one person, as well as a second phase of granting at least one entitlement to this person, the system may then comprise functional means able to implement each of the two phases of the method within one and the same piece of equipment, or else distinct physical entities each ensuring the implementation of one of the two main phases of the method.

DETAILED DESCRIPTION OF THE DISCLOSURE

FIG. 4is a basic diagram illustrating a phase of enrollment according to the invention, that may possibly precede a granting of entitlements. This phase of enrollment consists in generating a unique means of identification of a person22, in such a way as to avoid the problems of generating multiple means of identification to one and the same person as was explained in the introduction.

According to this figure, the person22has biometric data of their own, this biometry23of the person22is detected and then compared with a set of biometries stored in a biometric database26, corresponding to biometric data of persons having already been the subject of an enrollment, that is to say already obtained a means of identification. If the biometry23of the person22matches one of the biometries stored in the database26, this implies that the person22has already been the subject of an enrollment, and therefore has already received a biometric token. In this case, it is for example possible to decide not to re-generate a biometric token for this person22, or else to proceed with additional checks. When in step25, no match has been found between the biometry23and the biometries stored in the base26, this implies that the person22has not yet been the subject of an enrollment, and this justifies the generation of a means of identification for this person22. It will be noted that the verification step25is especially reliable since it is based on biometric data which literally characterize the relevant person.

Moreover, the person22wishing to follow an enrollment procedure, states their identity24. This identity is then the subject of a verificatory check in step27, this check possibly being of various kinds. It is for example possible to verify the presence of the stated identity24in a database28containing identity information on all the persons apt to come forward for an enrollment.

The biometric token29ultimately generated for the person22is made up of the biometry23and of the identity24of this person. For example, this token comprises elements of the biometry23, elements of the identity24, as well as a unique identifier of the token. This may for example be an identity card on which fingerprints of the person22have been affixed.

Thus, the enrollment illustrated inFIG. 4makes it possible to generate a means of identification which is unique for a given person, in so far as a check is made in a step25to verify whether the relevant person has already obtained a token. One thus prevents the granting of several biometric tokens to one and the same person, thereby limiting the subsequent possibilities of use of these various tokens, for example to obtain the granting of several entitlements on the basis of the various biometric tokens obtained by this person.

After the generation of the biometric token29associated with the person22, the database26is advantageously updated to take into account the biometry23, in such a way that the person22can no longer obtain a biometric token during a subsequent new enrollment procedure, once the biometric token29has been obtained.

In an advantageous embodiment of the invention, the biometric database26stores not only elements of biometry, but also identifiers of tokens. Thus, each biometry stored in the base26is associated with a biometric token identifier granted to the person possessing said biometry. A tie between the biometry verified and the token granted is thus retained, although without this tie allowing a direct correspondence between biometry and identity outside of the token. Specifically, the identifier of a biometric token is not kept in the identities verification database, but it is for example incorporated with the biometric token itself.

In this embodiment, it is therefore appropriate, with reference toFIG. 4, once the biometric token29has been generated for the person22, to associate the biometry23of the person22with an identifier of the biometric token29(step30), and then to store the identifier of the token29in association with the biometry23in the biometric database26.

It will be noted, that in the example described with reference toFIG. 4, a biometric token29has been generated so as to be associated with a person22. However, it is also possible to generate a biometric token for a set of persons. For example, a unique token can be generated for a group of persons having a tie between them, such as a family. In this case, the biometric token generated will advantageously bear biometry and identity elements relating to each of the persons of the group.

FIGS. 4A and 4Billustrate a variant embodiment for the enrollment phase, in which the unique means of identification associated with a person or with a given group of persons is generated in two stages.

The person107ofFIG. 4Apossesses a biometry108. As in the previous case, in a step109, a search is performed to establish whether a token has already been allocated for this biometry108, for example by verifying the presence of this biometry in a database of biometries110. If no token has yet been allocated to the biometry108, one is generated on the basis of the biometry108of the person107, and the database110is advantageously updated. Thus, the biometric token111is obtained on the basis of biometric data solely at this juncture. Optionally, the identifier of the token111is associated with the biometry108(step110), and this association is advantageously updated in the database110.

In a second stage, a person113, who may for example be the same person as the person107ofFIG. 4A, can have an identity added to the biometric token which was previously associated therewith. Thus, the person113ofFIG. 4Bpresents the biometric token115which was previously associated with them. A check is done in step116, to ensure that the biometric token115is rightly in the possession of the person113. For this purpose, the matching of the biometry114of the person113and the biometry on the basis of which the biometric token115was generated is verified, this information advantageously being registered on the token115. Moreover, the person113states their identity117. The latter is the subject of a verificatory check in step118, for example by searching for this identity in a database of identities119. After verificatory checks, the identity117is added to the biometric token115(step120).

The enrollment according to this embodiment thus consists of two independent and asynchronous phases. The biometric token associated with a person is ultimately generated on the basis of biometric data and of identity data, but it was possible to disclose and register these data at different moments.

Furthermore, it is possible to implement the second phase of such an enrollment repeatedly (illustrated inFIG. 4B), so as to register several identities of different kind on one and the same biometric token. For example, an identity may pertain to a civil status of the relevant person, while another identity is a professional identity.

A person possessing a biometric token, which was granted to them for example on completion of an enrollment procedure as illustrated inFIG. 4, can then claim the granting of one or more entitlements. This granting may be performed by virtue of the identity of the person who claims an entitlement, or else independently of their identity.

FIG. 5illustrates a case of granting an entitlement to a person on the basis of their identity. The person31who claims an entitlement may be for example the same person as the person22who has previously undergone an enrollment procedure. Said person possesses a biometry32as well as a biometric token33which was previously associated therewith. A check is then carried out to verify, in a step34, whether the biometry32of the person31and the biometry stored on the biometric token33presented by the person31do indeed match. If such is not the case, this implies that the biometric token33presented by the person31was not generated for this person and is therefore not associated with them. No entitlement is then granted in a case of this kind.

On the other hand, if the biometry32of the person31and the biometry on the basis of which the biometric token33was generated do match, this implies that the token33is rightfully in the possession of the person31. The identity of the person31is retrieved from the biometric token on which it is registered (step35). A check is then carried out to verify that the entitlement claimed has not already been granted to the person31on the basis of their identity (step36). For this purpose, a check is made to verify the presence, in a database37of the identities, storing the identities of all the persons having already obtained the relevant entitlement, of the identity retrieved in step35. It will be noted that should the granting relate to a set of distinct entitlements, the database37of the identities stores the identities of the persons having already obtained the granting of an entitlement from among the set of entitlements, in conjunction with this entitlement, in such a way as not to prevent a person having already obtained an entitlement of said set of entitlements from getting another one granted subsequently.

If the identity retrieved in step35does not appear in the base37, in conjunction with the entitlement claimed by the person31, this implies that this person has not yet been granted the entitlement that they are claiming. The granting of this entitlement is then carried out in step38. In the converse case, no entitlement is granted to the person31, since the latter has already obtained it previously. When the entitlement claimed by the person31is granted in step38, the database37is then updated to take account of this information, that is to say that the identity35of the person31is stored in the database37in conjunction with the entitlement granted.

In the example described with reference toFIG. 5, one seeks to grant an entitlement to a given person just once. However, it is also conceivable to grant an entitlement a predetermined number of times for a given person or a group of given persons. In this case, it may be advantageous to store moreover, in the database37, an indication relating to the number of actual grantings of an entitlement for each identity in conjunction with said entitlement. A check is then made to verify in step36whether the entitlement claimed by the person31has already been obtained for the identity retrieved in step35, a number of times equal to the predetermined number. One thus ensures that the entitlement will not be granted to the person31a greater number of times than said predetermined number.FIG. 6illustrates an embodiment of the phase of granting one or more entitlements for one or more persons, in which the granting is performed independently of the identity of the person. A person39having a biometry40and possessing a biometric token41, claims an entitlement. As in the previous case, the biometry40and that on the basis of which the biometric token41was obtained, for example in an enrollment procedure, and which is advantageously stored on the token41, are compared in step42. If the biometries match, this implies that the biometric token41is rightly associated with the person39. The identifier of the biometric token41, which is advantageously registered on the biometric token itself, is then detected in a step43.

Then in step44, a check is made to verify whether the entitlement claimed by the person39has already been obtained for such a token identifier. For this purpose, a database45storing the identifiers of tokens of all the persons having obtained an entitlement is advantageously consulted, the identifier of tokens being stored in conjunction with the entitlement granted for this identifier. When the entitlement has not yet been obtained for such an identifier, the entitlement claimed by the person39is then granted thereto during a step46, then this granting information is taken into account by the addition of the identifier of the token obtained in step43to the database45in conjunction with the entitlement granted.

Thus, the entitlement claimed by the person39has been granted thereto without the identity of this person ever being detected or stored. This embodiment is especially beneficial when the entitlement may be claimed by a set of persons by virtue of their capacity, for example the members of an association of anonymous persons.

As in the case described with reference toFIG. 5, the entitlement granted to the person39according to the embodiment ofFIG. 6, could be granted a predetermined number of times, rather than in a unique manner. In this case, the number of grantings of an entitlement for one and the same token identifier is advantageously the subject of an additional entry in the database45.

The granting of an entitlement according to the embodiments illustrated inFIGS. 5 and 6is therefore controlled, in so far as each person requesting the granting of an entitlement obtains a unique biometric token during a prior phase of enrollment, then the entitlement is granted thereto conditionally by virtue of information available from this biometric token. The chances of granting an entitlement only a predetermined number of times to one and the same person are thus increased.

Furthermore, the mechanism described above allows effective separation of the biometric data on the one hand and of the identity of the persons on the other hand. Specifically, none of the databases used in the enrollment phase, as in the entitlements granting phase, contains both biometry information and information relating to identities of persons. Only the biometric token generated during the enrollment phase in relation to a given person, contains a tie between the biometry and the identity of this person, so that this tie is not generally available other than from said person.

As far as the means for implementing the invention are concerned, a first entity105can be charged with the implementation of the enrollment phase. In this case, this entity105is then a device which coincides with the overall system104.

If the second phase of granting entitlements is moreover implemented, a second entity106is charged with granting entitlements, as has been represented diagrammatically inFIG. 12. The overall system104then consists of two distinct entities105and106and it allows the granting of entitlements. Each of the entities, within the system104, can operate independently, that is to say that a person can request in a first stage that they be assigned a biometric token. This operation is then carried out with the aid of the entity105. Next, said person can request the granting of an entitlement immediately following their enrollment, or, on the contrary, well after their enrollment. The granting of the entitlement is then performed by the entity106. In other embodiments set forth below, interactions are possible between the two entities105and106.

As a variant, the system104, allowing the granting of the entitlements, can group together within a single piece of equipment first functional means able to implement the enrollment phase described hereinabove (105then designates these first functional means), and second functional means able to grant entitlements in accordance with the second phase described hereinabove (106then designates these second functional means).

The embodiments of the invention that were described above, do not make it possible, however, to totally eradicate the risk of a person possibly getting associated with several biometric tokens, and possibly subsequently having the same entitlement granted several times, doing so by declaring several different identities.

Specifically, if the person22ofFIG. 4has obtained a unique biometric token29on completion of an enrollment phase, then claims to have lost their token29, they can undergo a new enrollment phase in the course of which they state a new identity, different from the identity24previously declared. If the step of verifying the identity27is not sufficiently reliable, as is sometimes the case in reality, it is possible for the person22to obtain a new biometric token generated from his biometry23and from the new identity that they have declared. This same person can then obtain the granting of an entitlement that they had already obtained, for example according to the principles described with reference toFIG. 5or toFIG. 6, since no entitlement has yet been granted for the new identity declared by the person22, nor for the identifier of the token newly obtained by this person.

FIG. 7shows an embodiment of the enrollment phase aimed at prohibiting the generation of several biometric tokens for one and the same person on the basis of different identities, and hence at reducing the risks of multiple granting of one and the same entitlement to this same person, on the basis of their various identities declared. Thus, according toFIG. 7, the person47can obtain a first unique biometric token56on the basis of their biometry48and of the identity49that they state during their first enrollment, in a similar manner to what was described with reference toFIG. 4. It is henceforth considered that this same person47attempts to have a new biometric token allocated by stating a new identity49. In this case, step50detects that a biometric token has already been allocated to this person by retrieving the biometry48of the person47from the database51storing the biometries of the persons having already obtained a token, these biometries being associated in the base with an identifier of the respective token.

A check is then made to verify the new identity49stated by the person47in step52. Given the existing risks that the person47states a different identity49from that that they had stated during their first enrollment, the verification of the identity of step52is advantageously performed with enhanced reliability in this case, for example by querying a database53of the identities containing multiple information on the identity of the persons. If the identity49stated by the person47is erroneous, it is then possible to choose not to generate a new biometric token for this person.

Furthermore, when step50has revealed that a token had already been allocated to the person47, the identifier of the biometric token which had been previously obtained by this person47is revoked (step54). This revocation may be done by registering the old token identifier associated with the person47, that is to say the identifier of the biometric token previously obtained by the person47, in a list of revoked identifiers55.

This list may be stored in a database. When the system allowing the granting of the entitlements comprises two distinct entities (one for generating the tokens and another for actually granting the entitlements), the database containing the list of revoked identifiers55must be consultable by the entity charged with the granting of the entitlements (entity106inFIG. 12).

As a variant, the list of revoked identifiers55set up by the entity implementing the enrollment phase (entity105inFIG. 12) is transmitted to the entity charged with the granting of the entitlements (entity106inFIG. 12). This transmission may be done according to diverse modes. For example, it may be done periodically, the complete list of revoked identifiers being transmitted at each period, or else only the revoked identifiers added to the list55since the last period are transmitted during a new period. It is again possible to transmit each revoked identifier to the entity charged with the granting of the entitlements as soon as this identifier is added to the list55, so as to have instantaneous transmission of the revoked identifiers.

The revocation of the identifier of the biometric token previously generated for the person47thus makes it possible to prevent the person47from being able to have two different biometric tokens in force.

A subsequent granting of the entitlements is then conditioned by the fact that the biometric token presented by a person is indeed in force.FIG. 8illustrates such a mode of granting an entitlement. A person59having a biometry60as well as a biometric token61claims the granting of one or more entitlements. As in the above-described cases of granting, a check is made in step62to verify a match between the biometry60and that stored on the biometric token61generated during a prior enrollment phase. When the biometries match, a check is carried out, in a step63, to verify whether the identifier of the biometric token61associated with the person59is in force or else if it has been previously revoked. For this purpose, a check is carried out to verify the presence or the absence of the identifier of the biometric token61in a list of revoked identifiers64.

The list of revoked identifiers64is obtained on the basis of the list of revoked identifiers55. For example, when the list of revoked identifiers55has been stored in a database accessible from the entity (physical or functional) charged with the granting of the entitlements, the list64is then the same as the list55, and it suffices to consult said database to conclude the revocation or non-revocation of the relevant biometric token. As an alternative, the list64is different from the list55, but it is updated on the basis of the latter during the transmission of revoked identifiers to a memory space of the entity charged with the granting of the entitlements, said transmission possibly being instantaneous or periodic, partial or complete, as indicated hereinabove.

If, in step63, it is concluded that the identifier of the biometric token61used by the person59has been revoked, it is then possible to choose not to grant the entitlement claimed to the person59. On the contrary, if the identifier of the biometric token61associated with the person59is indeed in force, one then proceeds as in the case described previously with reference toFIG. 5, to grant the entitlement to the person59during a step68, after having verified that the identity65of the person59registered on the biometric token61has not already been the subject of the granting of the same entitlement, once or, more generally, a predetermined number of times.

In the embodiment illustrated inFIG. 9, an entitlement claimed is granted to a person69on the basis of the identifier of the biometric token71associated therewith, as in the case described previously with reference toFIG. 6. As in the case illustrated inFIG. 8, a check is made in step73to verify that the identifier of the biometric token71has not previously been revoked, by querying a list of revoked identifiers74compiled on the basis of the previously described list of revoked identifiers55.

The embodiments of the invention that were described above do not exclude the possibility that a person might usurp the identity of another person and thus obtain a biometric token relating to this usurped identity, to the detriment of this other person. If the person47ofFIG. 7has obtained a first biometric token56, then claims to have lost it, said person may then be the subject of a new enrollment phase in the course of which they state the identity of another person47′. If the verification of the identity of step52is not sufficiently reliable, it is then possible for the person47to obtain a new biometric token generated on the basis of their own biometry48and of the identity of the person47′.

To avoid this situation, it is possible to proceed according to one of the embodiments illustrated inFIGS. 10 and 11.FIG. 10shows a person78having a biometry79and an identity80that they state for verification in step87. If it is noted, while searching for the biometry79in a database83containing the biometries of all the persons having already obtained a token, the biometries being respectively associated with identifiers of corresponding tokens, that the person78has never requested the generation of a biometric token, then a biometric token84is generated on the basis of the biometry79of the person78and of the identity80that they have declared and which has been verified in step87. The biometry79of the person78is then associated with the identifier of the biometric token84(step85) so as to be the subject of a new entry in the database83.

Furthermore, a biometric key relating to the person78is calculated (step86). This biometric key is a code generated in a robust and reproducible manner, apt for characterizing the person78sufficiently for the latter to have a different key value from any other person with a chosen predetermined level of probability, but not sufficiently characterizing to make it possible to retrieve the biometric data relating to the person78.

By way of example, the biometric key can take a few tens or a few hundreds of different values, when the number of persons apt to claim the granting of entitlements is a population of a few million or a few tens of millions of persons. It may for example take as a value a letter of the alphabet between A and Z (26 different values) or else a number with two digits between 00 and 99 (100 different values). Advantageously, the number of values of the biometric key is adapted to the calculational power necessary to calculate all the combinations by brute force.

The biometric key is calculated on the basis of biometric elements of the relevant person. For example, if the biometric data79used to identify the person78are fingerprints, the biometric key calculated in step86for this person78can be obtained on the basis of a coding of the general shape of each print of the fingers of this person78, given of course that this coding makes it possible to obtain an almost uniform distribution of the codes for the various possible shapes of the fingerprints. As a variant, the biometric data79of interest of the person78, relate to the iris of the eye of the person78. In this case, the biometric key could be calculated advantageously according to a statistical operation based on the coding of the iris.

Once the biometric key has been calculated for the person78, the identity of the person78is retrieved from the token84generated for this person (step92). Next, the biometric key obtained in step86is stored in a database89, while linking it to the identity of the person78. This amounts to saying that the database89stores the whole set of identities of the persons apt to request the granting of the entitlements, each identity being associated with a biometric key of the corresponding person. In this kind of case, information regarding identities is then stored in conjunction with biometry information. However, given the above-described weakly discriminating mode of calculation of the biometric key, it is not to be feared that the relation stored in the base89may make it possible to retrieve the identity of a person on the basis of their biometry, or vice versa.

If subsequently, the person78usurps the identity of another person and wishes to have a biometric token generated on the basis of this usurped identity, one proceeds as follows: after having detected that the person78had already had a biometric token allocated (step82), the biometric key81associated with the person78is calculated. Next, on the basis of the identity80declared by the person78, a check is performed to verify this identity, if possible in a more reliable manner than in the current case (step87). Then, in step88, the biometric key81is compared with the biometric key associated with the identity80stated by the person78in the database89.

If the biometric keys compared are identical, it is then possible to conclude therefrom with a reasonable degree of certainty that the identity80is indeed that of the person78. On the other hand, if the biometric keys compared differ from one another, the identity80stated by the person78is certainly usurped. In the latter case, it is then possible to choose not to generate new biometric tokens to the person78on the basis of this usurped identity.

As in the embodiment described above with reference toFIG. 7, it is possible to revoke the identifier of the old biometric token associated with the person78(step90), when it has been concluded that the identity80stated by the person78was right on completion of steps87and88. For this purpose, the old token identifier is added to a list of revoked identifiers91, said list possibly being transmitted to an entity (physical or functional) charged with the actual granting of the entitlements.

In a variant embodiment, illustrated inFIG. 11, a person93has a biometric token98generated, whilst no biometric token had been associated with this same person previously. Next, a random key is calculated for this person93(step99), which is stored on the one hand, in a biometric database97, in conjunction with the biometry94of the person93, and on the other hand, in a database of the identities101, in conjunction with the identity of the person93obtained from the biometric token98generated for this person.

If the person93undergoes a new enrollment phase, step96detects that a biometric token has already been associated with this person in the past, by consulting the database97, on the basis of the biometry94. Next, a particularly careful check is performed to verify the identity95stated by the person93(step100). Also, a comparison is performed between the random keys stored in the database97for the biometry94, and in the database101for the identity stated95(step102).

If the random keys stored in the databases97and101respectively, are not mutually consistent, it is possible to conclude therefrom with a reasonable degree of certainty that the identity95stated by the person93during this second enrollment has been usurped and therefore corresponds to the identity of another person having already themselves undergone an enrollment phase.

Conversely, if step102indicates that the random keys stored in the databases97and101are identical, it is then probable that the identity95stated by the person93during this second enrollment is indeed the identity of this person, and not a usurped identity. In this case, it is possible to choose to generate a new biometric token103for the attention of the person93, replacing the token which had previously been allocated to them.

Although not represented in this figure, it is of course possible as in the cases described above, to revoke the identifier of the old biometric token which had been associated with the person93, in such a way that this person only has one token in force at a time.

In the embodiment of the invention illustrated inFIG. 11, the calculation of the key in step99is totally random, thereby limiting the risks of fraud consisting in searching, on the basis of biometric data of a person, for a corresponding key.

It is also noted in this latter embodiment that an identical field (the random key) is stored both in a biometric database97and in a database of identities101. However, the random key being calculated in such a way as to be weakly discriminating (it may for example take between a few tens and a few hundred different values, as in the case described above), it is impossible for a person having access to the databases97and101to retrieve with certainty a correspondence between the biometry and the identity of a person solely on the basis of the random key.