EP4241190A1

EP4241190A1 - Authentication method secured by structural decoupling of personal and service identifiers

Info

Publication number: EP4241190A1
Application number: EP21819918.0A
Authority: EP
Inventors: Daniel Krob
Original assignee: A3bc Group
Current assignee: A3bc Group
Priority date: 2020-11-09
Filing date: 2021-11-09
Publication date: 2023-09-13
Also published as: WO2022096841A1; US20230410098A1; FR3116132A1

Abstract

The invention relates to a method for enabling secure transactions without the physical support of a security identifier and, in particular, without a token, consisting in recording on a first computer device B a unique digital identifier ID₁ associated with a unique user U_i, the profile ID₁ being associated with at least one service identifier ID_si associated with a service S_i registered on a second computer device S which is different from the first computer device B, the service S_i being accessible by the user U_i, and, during a transaction, acquiring the digital identifier ID_i of a user U_i, transmitting said identifier to the first computer device B for comparison with the registered ID identifiers and searching for and activating, on the computer device S, at least one service associated with the user U_i. The new user registration step comprises: - when a central computer device receives a profile P_i, executing a step for generating a temporary random master key X - when the central computer device receives an identifier ID_i, executing a step of searching for the pair (ID_i, IDRx) on the first computer device B and applying the inverse function FR-1 to the identifier IDRx to determine the key X.

Description

DESCRIPTION

Title x SECURE AUTHENTICATION PROCESS BY THE

STRUCTURAL DECOUPLING OF PERSONAL IDENTIFIERS AND

SERVICES

Field of the invention

The present invention relates to the field of authentication of a user carrying out electronic transactions using a terminal connected to computer equipment or access to a physical system.

Transaction security is an essential issue, and has given rise to many solutions that limit the risk of fraud with regard to the author of the transaction or the nature of the transaction.

Biometric recognition techniques based on image capture systems coupled to a central database storing personal information constitute a path that comes up against harmful limits. Indeed, the biometric data may vary slightly. To take these variations into account, provision is made to retain only a small part of points considered to be invariant. However, this translates to:

- Risks of false positives, namely the validation of biometric data whose invariant points are effectively identical or similar, but which actually come from two different people. This is how a person was arrested on the basis of fingerprints showing an unusual proximity to those of an alleged assassin. It is also the case for the presentation of a fingerprint cast.

- Risks of false negatives, namely the absence of validation of biometric data of a person whose certain invariant points were masked, or modified by an artefact, for example the wearing of a mask.

The invention therefore relates to the field of authentication excluding biometric data, and more specifically the field of electronic transactions activated using a reliable unique identifier such as for example a QrCode, an alphanumeric identifier, an email address , a unique identification number such as an IBAN or a social security number, and securing the process of registration of the identifier, storage and verification to reduce the risks in the event of computer attacks from a server of the transaction system.

State of the art

We know the European patent application EP1488359A4 which relates to a method for performing an online transaction through a transaction manager. The method described in the invention comprises generating a one-time transaction request identification; the transaction manager linking this identification to banking information of a subscribed user; providing the transaction request identification to the subscribed user who is making a request to purchase a product or service of value from a merchant. The purchase request consists of providing the identification of the transaction request to the merchant. The merchant sends a payment request to the transaction manager for a transfer of funds equal to the value from the user to the merchant; the payment request including the identification of the transaction request and the value. the transaction manager verifies the validity of the identification of the transaction request, then it invalidates the reuse of this identification. If the identification of the transaction request is valid, an electronic funds transfer request is sent to a financial institution in order to allow the transfer of the cashed value from the user to the merchant, the electronic funds transfer request comprising banking information.

European patent EP2839603B1 describes a user authentication method comprising the execution, by a processing system, of the following operations:

• The receipt of a request from a user to launch an authentication session, the request comprising a unique identifier of the user,

• Access, by means of the unique identifier, to a recording stored in memory in a memory associated with the user,

the stored record comprising at least code value complexity preference data that defines a user-preferred level of complexity for a user in validating user input received in response to the presentation of security matrices, and a user-defined keyword consisting of an ordered sequence of symbols comprising members of a predetermined symbol set selected from one or more symbol sets supported by the processing, where the symbols of the ordered sequence have been previously selected by the user regardless of other user selections,

• Generating a one-time security matrix that is valid only for the user during the authentication session, and that includes a mapping between each symbol within the predetermined symbol set and a code value that is specific to the authentication session and randomly selected from a code set that is distinct from the predetermined symbol set,

• Transmitting the one-time security matrix for presentation to the user, wherein the one-time security matrix presented to the user includes symbols from the predetermined symbol set corresponding to the selected code values randomly among the code set,

• Receiving an ordered sequence of code values selected from the single-use security matrix and entered by the user, based on the user-defined keyword and code value complexity preference data , in response to the presentation of the disposable security matrix ,

• Validation of the received ordered sequence of code values by comparison to a corresponding sequence of code values generated, but not transmitted, by the processing system based on the keyword defined by the user in the retained record in memory, complexity preference data of value of single-use code and security matrix, and

• Generating an authentication result of the authentication session based on the comparison.

Disadvantages of prior art solutions

The solutions of the prior art present a major technical problem because they leave open possibilities of computer attack.

One of the sources of vulnerability lies in the management of identifiers. Knowing the identifier makes it possible to go through a first step in the authorization procedure for a service, the information being used for the next step, which is the authentication of the user who has transmitted — legally or fraudulently — a valid identifier. . The security of the identifier depends on the measures taken by the user to keep it secret, and if necessary on the electronic means provided on the physical support of the identifier when it is recorded on a key, a card or a portable equipment such as a telephone.

The solutions of the prior art have a second drawback which relates to the security of the authentic data recorded during the creation of a user's account. This data is generally recorded in a secure DMZ zone of the computer equipment, but in the event of a computer attack, it remains possible to recover all the data associated with user identifiers.

A third drawback lies in the risk of data interception and fraudulent reuse of this data. A fourth disadvantage lies in the risk of creating a false account to access the services of a third party user.

It is implicitly accepted that identification is vulnerable and requires little computing power on the user's equipment, insofar as security will come from the robustness of the authentication protocol and optionally certification, requiring resources more powerful processing methods, pooled at the level of computer equipment.

Solution, provided by the invention

To remedy these drawbacks, the present invention relates, in its most general sense, to a secure transaction method for a security identifier, in particular without a token, consisting in recording on a first computer equipment B a unique digital identifier ID _± associated with a unique user. U ±, said profile ID _± being associated with at least one service identifier ID _{S ±} associated with a service S ±, recorded on a second computer equipment S distinct from said first computer equipment B, said service S ± being accessible by the user U±, and, during a transaction, to acquire the digital identifier ID _± of a user U±, to transmit it to said first computer equipment B for comparison with the registered identifiers ID and to search and activate on the computer equipment S at least one service associated with the identifier of the user U ±, characterized in that the step of registering a new user comprises the steps known living:

- at the time of receipt by a central computer equipment of an identifier ID _± and a service identifier ID _{S ±} , the execution of a step of generation of a master key, characterized in that said master key is a temporary random key X,

- then a step of generating a reference identifier IDRx, calculated by applying a non-reversible FR reference cryptographic function to said key, and recording in a computer table of the unique pair (ID _± , IDRx) recorded on computer equipment B,

- and finally a step of generating at least one reference identifier IDSEx, calculated by applying a non-reversible FSE reference cryptographic function, distinct from the FR function, to said temporary random key, and recording in a computer table of the unique couple (ID _S± , IDSEx) recorded on a computer equipment S, in that the execution of a transaction comprises the following steps:

- at the time of receipt by said central computer equipment of an identifier ID _± , the execution of a step of searching for the couple (ID _± , IDRx) on said first computer equipment B and application of the inverse function FR -1 to the IDRx identifier to determine the temporary random key,

- and finally the search for at least one service S ± on a second computer equipment S by applying the FSE function to said temporary random key, in order to calculate the identifier IDSEx and obtain the identifier ID _{S ±} associated with the service S ±.

Advantageously, it also comprises, at the time of reception by a central computer equipment of an identifier ID _± , a step of generating an identifier of IDPEx reference calculated by applying a non-reversible FPE cryptographic function, distinct from the FR and FSE reference functions, to said random key X and recording in a computer table of the pair (ID _P± , IDPEx), where IDpi is a personal information identifier P ± associated with the user U ± and accessible to the latter, stored on a third computer equipment P distinct from said first and second computer equipment B and S, and at the time the transaction is carried out, the search for personal information P± on said third computer equipment P by applying the function FPE to said temporary random key, in order to calculate the identifier IDPEx and obtain the identifier IP _p± associated with the personal information P±.

The invention also relates to a set of computer equipment for carrying out secure transactions of a tokenless security identifier, characterized in that said set of computer equipment comprises computer equipment allowing access to a first computer equipment B and to at least one second service computer equipment S, and a key computer equipment forming the support for said non-reversible functions.

Preferably, the assembly further comprises computer processing equipment for carrying out the control, security and plausibility processing of the information coming from the users' equipment.

The invention further comprises a computer program for controlling the execution on a computer equipment of the realization of a secure transaction of a security identifier without token characterized in that it consists of a code controlling the acquisition of a digital identifier coming from remote equipment, the processing of said identifiers in accordance with the aforementioned method and the execution of the data exchange protocol between remote equipment and computer equipment for the operation of said.

Detailed description of a non-limiting embodiment

The present invention will be better understood on reading the following description, with reference to the appended drawings where:

[FIG. 1] FIG. 1 represents the hardware architecture of computer equipment for the implementation of the invention,

[FIG. 2] Figure 2 shows the block diagram of one invention,

[FIG. 3] figure 3 represents the diagram of data exchanges for the enrollment procedure of a new user,

[FIG. 4] figure 4 represents the data exchange diagram for the enrollment procedure of a user to a new service,

[FIG. 5] FIG. 5 represents the data exchange diagram for the service access procedure by an enrolled user.

Hardware architecture of the invention

Figure 1 shows a block diagram of the hardware architecture of a system for implementing the invention.

The user has a unique identifier which can be simply memorized, or recorded on a device in the possession of the user and transferred to a control terminal by entering it on a keyboard or a touch screen, or transmitting it from a memory by a physical link such as a connector or an optical or radiofrequency link.

The input and output computer equipment (0) receives the information flows from the user equipment, manages the queues, for on-the-fly distribution on the processing computer equipment (1) and the returns to input terminals or identifier transmission equipment. This input and output equipment (0) also carries out control, security and plausibility, and transmission processing in order to verify that the information transmitted is indeed of a compliant nature. These include checking whether the identifier of the terminal or of the equipment transmitting the identifier (for example its IP address) is on a terminal registered on a blacklist, or whether the information presents anomalies representative attempted attacks, saturation or fraud.

The computer equipment (0) opens a transactional session to interact with the equipment (1) giving access to the equipment (2 to 4) to obtain the user profiles, services and personal information and to react with the equipment (0) to exchange with the user concerned by a transactional session managed in synchronous or asynchronous mode.

The computer equipment (2 to 4) manages the consolidated access to the user profiles, services and personal information, by interacting with a key computer equipment (5) forming the support for the non-reversible functions implemented by the method according to the invention.

The computer equipment (6) makes it possible to administer the entire system, in particular keeping track of all the transactions, in order to allow the auditing of transactions and in the event of a physical crash, the restoration of transactions.

FIG. 2 represents an example of a functional diagram, FIGS. enrollment of a user enrolled in a new service, and for the request for access to a service by an enrolled user.

Procedure for enrolling a new user

The new user first proceeds to an enrollment via a computer equipment (0) as illustrated by FIG. 3. He opens a session with the computer equipment (1) and transmits a digital file corresponding to an enrollment request. This file contains an identifier, profile data and personal data. It may be transmitted in encrypted form.

The customer accesses the service via computer equipment (0) which includes a means of entering or transmitting an identifier, for example a keyboard, a QRCode reader, a radiofrequency module, a connector for receiving a identifier registration device or an application in charge of transmitting the identifier. This equipment (0) is connected to a network to open a session with the system (100) which hosts the set of computer equipment constituting the hardware architecture of the invention.

The first function (10) consists in recovering, controlling and transmitting the information necessary for the transaction, in particular the digital identifier acquired by the equipment computer (0) as well as associated information (for example the geolocation of the terminal, the identifiers of the terminal or of the application in charge of transmitting the identifier (IP address, various identifiers such as SIM card, etc.) or 1 'timestamp) , as well as information on the nature of the transaction. This information comes from the identifier of the supplier/terminal pair, for example when it is a terminal from a supplier made available to users, or from the identification of the service access application. Function (10) also opens a transactional session for each user.

Procedure for enrolling a user in a new service

The user enrolled as explained above then proceeds to an enrollment in services via his computer equipment (0) as illustrated by FIG. 4. He opens a session with the computer equipment (1) and transmits a digital file corresponding to a service registration request. This file contains a service identifier, profile data and personal data. It may be transmitted in encrypted form.

This process (11) is integrated into a processing chain linked to a transactional session opened for each user by the function (10). For this purpose, each transactional session consists in transmitting, controlling and reconciling the user profiles, the service identifiers and the personal information provided by the function (11), then in obtaining the service selected by the customer.

This processing (11) is carried out by the computer equipment (1), by interacting with the computer equipment (2 to 4) and (5). The system (100) also integrates administration functions and functions in charge of traceability and security protocols.

Procedure for requesting user access to a service

The user enrolled as explained above can then proceed to requests for access to previously enrolled services as illustrated by FIG. 5. He opens a session with the computer equipment (1) and transmits a digital file corresponding to a request for access to the service. This file contains an identifier and profile data. It may be transmitted in encrypted form.

This request is checked by the equipment (1) to check whether the user is actually enrolled, and whether the requested service is enrolled. If this is the case, it transmits the access request to the computer equipment (2) corresponding to the requested service. This equipment (2) extracts the identifier IDR _X from the identifier ID and performs a check of the profile recorded in the request. In case of erroneous control, the task is stopped by an interruption procedure and optionally a notification to the equipment (1) which transmits it to the equipment (0) of the user. If the check is positive, the computer equipment concerned (2) opens a session with the computer equipment (5) to obtain the public key KR then proceeds to calculate the source value X from a decryption function F ^{- 1} (KV,Y) as discussed in more detail below.

This source value thus calculated is controlled by the equipment 2, and transmitted to the equipment (1).

The equipment then makes a request for access to the service (X) by a session with the equipment (4), which opens a session with the equipment (5) to transmit a request access to the KSE key. This KSE key is transmitted in response to the equipment (5) which then proceeds to calculate IDSE _X =FR(KPE, X)

From this information, the equipment (5) extracts the identifier IDS ± and the service data to transmit them to the equipment (1) which transmits them via the session initially opened to the equipment (0) of the 'user.

Credential creation and identification protocols

The following description presents in more detail the protocol for creating identifiers, then in the following part, the protocol for identifying from a digital identifier presented to the system.

One of the important aims of the invention is to guarantee data security natively integrated into its architecture ("by design") because the reference identifier of the digital identifier and the reference identifiers of the services are structurally different, their generation being managed by an algorithm based on a one-way cryptographic function so as to be able to perform reconciliations on the fly according to transactional needs.

The proposed mechanism is based on the use of cryptographic protocols such as AES with keys of size greater than 128 bits, for example RSA with a key of 2048 bits.

The system operator must choose one-way cryptographic functions F to manage his exchanges with the sources of storage of the information used. They will be referred to below as FR (for the reference function), FSE (for accessing, storing and updating service information) and FP (for accessing, storing and updating service information). personal informations) . These functions will allow computer equipment (2 to 4) to calculate in real time values Y = F(KQ,X) according to a source value X and using a public key KQ so that knowledge of Y does not allow to go back to X in an algorithmically realistic way (the reconstruction times of the source value X having to be prohibitive in practice) .

To go back to X, it must be necessary to have a private key KV kept secret which makes it possible to reconstruct X = F ^_ ^X (KV,Y) from Y by using a decryption function F ^-1 .

The generation of reference identifiers, service identifiers and personal identifiers of a user U± will then be done according to the following protocol:

The computer equipment (1) draws a random value X at random, for example using a hash function to statistically avoid collisions.

The computer equipment (2 to 4) interact with the computer equipment (5) to obtain the public keys KR, KPE and KSE to respectively manage the exchanges concerning the identification information, the services and the personal information.

The IT equipments (2 to 5) manufacture the IDR reference identifier and at least one IDSE service identifier, as well as an IDPE personal information identifier, if applicable, according to the following simple rules (in the event of a collision with an existing identifier, a new X value will be generated):

RDI = FR(KR, X)

IDPE = FPE(KPE, X) IDSE = FSE(KSE, X) .

In this way, the identifiers are well linked across

X, which makes it possible to reconstitute an identifier from the reference identifier using the private cryptographic key which allows the decryption of the reference identifier and therefore to reconstitute the random value X from their knowledge. Customer services and personal information, if any, belonging to a given natural person, recognized using his digital identifier, can therefore be reconstructed in this way.

Claims

1 - Secure transaction authentication method of a security identifier, in particular without a token, comprising a step of registering a new user comprising the following steps:

- to record on a first computer equipment (0) an ID profile _± associated with a single user U ±, the said profile ID _± being associated with at least one service identifier ID _{S ±} associated with a service S ±, recorded on a second computer equipment (2 to

4) distinct from said first computer equipment (0), said service S± being accessible by the user U±,

- at the time of receipt by a central computer equipment (1) of an identifier ID _± and a service identifier ID _{S ±} , the execution of a generation step of a master key, and, during a transaction, to proceed with a step of opening a session on a network comprising the equipment (0) of the user and system (100) which hosts a set of computer equipment comprising equipment (1) giving access to equipment (2 to 4) to obtain user profiles, services and personal information and to react with the equipment (0) as well as key computer equipment (5) interacting with said computer equipment (2 to 4) to provide the public keys KR, KPE and KSE and manage the exchanges concerning identification information, services and personal information respectively;

At a step (10) of retrieval, control and transmission of the information necessary for the transaction, in particular the digital identifier acquired by the computer equipment (0) as well as associated information, and in steps (11) consisting of transmitting, controlling and reconciling the user profiles ID _± , the service identifiers and the personal information provided by the function (11), then obtaining the service selected by the customer by carrying out the acquisition of the profile ID _± of a user U ±, in transmitting it to said first computer equipment for comparison with the registered identifiers ID and searching for and activating on the computer equipment S at least one service associated with the identifier of the user U ±, characterized in that the step of registering a new user comprises the following steps:

- at the time of reception by a central computer equipment (1) of an identifier ID _± and of a service identifier ID _{S ±} , the execution of a step of generating a master key, characterized in that said master key is a temporary random key,

- then a step of generating a reference identifier IDRx, calculated by applying a non-reversible reference cryptographic function FR to said temporary random key, and recording in a computer table of the unique pair (ID _± , IDRx) recorded on computer equipment B,

- and finally a step of generating at least one service identifier IDSEx, calculated by applying a non-reversible FSE reference cryptographic function, distinct from the FR function, to said temporary random key, and recording in a computer table of the single pair (ID _S± , IDSEx) recorded on computer equipment (2 to 4). - 19-

2 - Secure transaction authentication method of a security identifier according to claim 1 characterized in that it further comprises at the time of receipt by a central computer equipment of an identifier ID _± , a step of generating 'an IDPEx reference identifier calculated by applying a non-reversible FPE cryptographic function, distinct from the FR and FSE reference functions, to said random key and recording in a computer table of the couple (ID _P± , IDPEx) , where ID _P± is an identifier of personal information P± associated with the user U± and accessible to the latter, stored on a third computer equipment P distinct from said first and second computer equipment B and S, and at the time of the carrying out the transaction, searching for personal information P± on said third computer equipment P by applying the FPE function to said key X, in order to calculate the identifier IDPEx and obtain r the IP identifier _p± associated with the personal information P±.

3 - Set of computer equipment for carrying out secure transactions of a security identifier without token, characterized in that said set of computer equipment comprises input computer equipment for receiving information flows from terminals users, the execution and finalization of transactions in accordance with the method of claim 1, computer equipment providing the interface with a first computer equipment B and at least one second service computer equipment S, and equipment computer forming the support of said non-reversible functions.