France Telecom

Orange

Sébastien Canard

Jacques Traore

Marc Girault

Eric Malville

Stéphane Guilloteau

Marie Paindavoine

Julien Devigne

Iwen Coisel

Olivier Sanders

Cécile Delerablee

David Arditti Modiano

Baptiste Olivier

Nicolas Desmoulins

Solenn Brunet

Dominique Le Hello

Aida Diop

Nizar Kheir

Roch Lescuyer

Amandine Jambert

François Boudet

Bruno Cosnefroy

Sidonie Caron

Matthieu Gaud

A technique for protecting a cryptographic key. A user has an identifier and an associated password. The first cryptographic key is designed to decrypt a piece of encrypted data. The user device generates a second cryptographic key by applying a key derivation algorithm to at least the password, then encrypts the first cryptographic key by applying an encryption algorithm parameterized by the second cryptographic key. The user device then provides the encryption of the first cryptographic key to a management device for storage. A response associated with a question is obtained from the user. The user device calculates a result of an application of a function to at least one response associated with a question, then provides a value dependent on the result to a management device for storage. The value then enables the user device to determine the password when it has the response to the corresponding question.

Technique for protecting a cryptographic key by means of a user password

A method is provided to anonymize 'initial' data stored in a database of a computer system and resulting from aggregating personal data relating to a plurality of individuals. The method includes: an identification act identifying in the initial data a set of data that is 'sensitive' that would be affected by personal data relating to one individual being added to or removed from the database; a partitioning act partitioning the sensitive data set into a plurality of subsets as a function of a sensitivity level of the sensitive data; a determination act determining a sensitivity level for each subset; and an anonymization act anonymizing the initial data and including, for each subset, adding noise to the sensitive data of that subset with a noise level that depends on the sensitivity level determined for the subset.

Method and device for anonymizing data stored in a database

A method for detecting intrusions uses a searchable enciphering algorithm and includes: generating a trap bypass key for a security device, which is able to determine keywords characteristic of intrusions, generating by the security device a trap for each keyword by using the trap bypass key; providing the traps to an intrusions detection device; intercepting by the detection device character strings sent on the network by a sender and enciphered with a public key of a receiver; applying by the detection device a test procedure on the character strings enciphered using the traps; and detecting an intrusion on the network if there exists according to the test procedure an enciphered character string representative of a cipher of a keyword.

Method of enciphered traffic inspection with trapdoors provided

One embodiment relates to a method for enabling an entity to delegate calculation of a bilinear pairing value e(A,B) between two values A and B to a calculation server. The entity may select public elements Pand Pand secret elements Sand S, two of the elements from among P, P, S, and Sbeing selected to be equal to A and B, generate elements R=vS, R=uS, T=uP+S, T=vP=S, whereandare random numbers, and transmit R, R, T, and Tto the calculation server. The server may calculate (a)=e(T,T)[e(R,P)e(P,R)], and (a)=e(D,D),anddesignating two integers equal to 1 or to an integer, Dand Ddesignating two public elements from among A and B or from among Rand Rand transmit aand ato the entity. The entity may obtain the value e(A,B) from aor a

Method and system for delegating calculation of a bilinear pairing value to a calculation server

One embodiment relates to a method of updating, by an electronic device of a first user of a tree of data files and/or folders of the first user stored in a storage server configured to implement a re-encryption mechanism, this tree comprising at least one target folder that the first user has authorized a second user to access by providing the storage server with a re-encryption key for this target folder from the first user to the second user.

Method of updating a file tree stored on a storage server

A method of anonymous access to a service, comprising the allocation, by at least one certifying entity, of a plurality of certificates to a user entity, the certificates being calculated on the basis of at least one attribute associated with the user entity, the calculation, by the user entity, of an aggregated certificate on the basis of a plurality of certificates among the certificates allocated to the user entity, the calculation, by the user entity, of a proof of knowledge of the aggregated certificate and a verification, performed by a verifying entity, of at least one of these certificates by means of said proof of knowledge, the access to the service being provided by the verifying entity to the user entity as a function of the result of this verification.

Anonymous access to a service by means of aggregated certificates

A method for unique authentication of a user including federating an identity of said user for said service provider and an identity of the user for an identity provider, the federating including the steps of generating a user alias for that service provider and sending said identity provider a masked alias deduced from said alias, the identity provider associating said masked alias for that service provider with the identity of the user for the identity provider and sending the user elements for calculation by the user of a signature of a message containing the non-masked alias calculating said signature and sending the service provider said message with said signature, and the service provider verifying said signature, authenticating the user, and associating said alias with the user's identity.

Method for the unique authentication of a user by service providers

The invention relates to cryptographic method for the anonymous authentication and the identification of a user entity (U) respectively by a checking entity (D) and an identifying entity (O). According to this method, the checking entity (D) receives () from the user entity (U) at least one first signature (&#x3c3;) and a first message (m), and checks () the first signature (&#x3c3;) using the first message (m) in order to authenticate the user (U), and the identifying entity (O) receives () from the checking entity (D) a second signature (&#x3c3;') connected to the first signature (&#x3c3;) and identifies () the user using the second signature and a secret key particular thereto. The invention also relates to a cryptographic system for implementing said method.

Crytographic method for anonymous authentication and separate identification of a user

A system for managing sensitive personal data includes a first data processing subsystem and a second data processing subsystem. The first data processing subsystem includes a generating unit and a private database. The generating unit generates a common key from data identifying a person. The private database associates the common key with the identification data. The second data processing subsystem includes an obtaining unit, a generating unit, a receiving unit and a storing unit. The obtaining unit obtains the common key. The generating unit generates a random number from the common key. The receiving unit receives a registration message including sensitive personal data of the person and the random number. The storing unit stores the personal data in a second database in association with the random number and the common key.

System and method for the anonymisation of sensitive personal data and method of obtaining such data

The invention relates to a method of authenticating a radio tag by a radio reader, the tag possessing an identifier accessible to the reader via a database of tag identifiers, comprising: dispatching an authentication request by the reader to the tag, dispatching by the tag, a response, calculated by applying a first function to at least the identifier, a calculation by the tag and by the reader of a new identifier, by applying a second function to the identifier, comprising: if the response dispatched by the tag corresponds to a result obtained by applying said first function to an identifier of the base, a dispatching by the reader a first value, calculated by applying a third function to said identifier of the base.

Method of authenticating a radio tag by a radio reader

A method for authenticating an entity by a verifier, the entity having an identifier, the verifier having a pair of private and public keys, comprising: sending to the entity a first random number selected by the verifier; a step wherein the entity encrypts a value by means of the public key of the verifier, said value including the first random number and an authentication datum on which the identifier of the entity depends; and the entity of said encrypted value sending a reply to authenticate said entity. The invention can be applied to the field of low-cost cryptography, especially the field of radio-identification.

Method for authenticating an entity by a verifier

The cryptographic scheme subdivides time into periods with an index j=0, 1, 2, etc. A public key indicates elements u and v of a first cyclic group Gof prime order p and, for each period j, an integer sbetween 0 and p&#x2212;1 and elements gof the group Gand g, wand hof another cyclic group Gof order p. The private key of a member of the group indicates an integer xbetween 0 and p&#x2212;1 and, for each period j, an element Aof the group Gsuch that A=[A/g]for 1&#x2266;n&#x2266;j. To sign a message during a period j&#x2267;0, the member selects two integers &#x3b1; and &#x3b2; between 0 and p&#x2212;1, calculates T=u, T=A&#xb7;v, S=gand S=e(A, h)where e(., .) is a bilinear map of G&#xd7;Gonto G, and determines according to the message the data that justify the fact that the elements T, T, Sand Sare correctly formed with knowledge of the private key of the member for the period with index j.

Group signature with local revocation verification with capacity for lifting anonymity

The invention relates to a method for generating a list signature for a message to be signed, said method comprising steps which are carried out by an electronic material support of a member of a list. During said step, the electronic material support only generates an electronic signature according to a sequence number supplied to the electronic material support by a certifying authority, according to evidence of belonging to the list of members, to data relating to the electronic material support, and optionally to a key of an authority qualified to lift the anonymity of the generated signature.

Method and system for generating a list signature

The present invention relates to a method of access to a service consisting in i) identifying and registering a client (C), ii) authenticating the client to an anonymous certification authority, iii) authenticating the client by producing an anonymous signature and opening and maintaining an anonymous authentication session with a server (Se), and iv) selectively allowing contact between the server (Se) and the anonymous certification authority (ACA) to revoke the anonymity of the client (C) using the signature provided in step iii). The invention also relates to a system for opening and maintaining an authentication session guaranteeing non-repudiation.

Method and system with authentication, revocable anonymity and non-repudiation

The invention concerns a system enabling a member (M) of a group (G) to produce, by means of customized data (z; K), a message (m) accompanied by a signature () proving to a verifier that the message originates from a member of the group (G). The invention is characterized in that the customized data is in the form of an electronic physical medium (). Advantageously, the latter also incorporates: encrypting means (B) for producing a customized cipher (C) from the customized data prior to the signature S of the message (m), means (B) for producing a combination of a message m to be signed and the cipher (C) associated with said message, for example in the form of a concatenation of the message (m) with the cipher (C), and means (B) for signing (Sig) the message (m) with the customized data (z; K) in the form of a cipher (C) associated with said message. Advantageously, the physical medium is a smart card () or the like.

Growing community of inventors

Caen, France

Sébastien Canard