Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
  • H04L9/32—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
  • H04L9/3236—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials using cryptographic hash functions
  • H04L9/3242—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials using cryptographic hash functions involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F21/60—Protecting data
  • G06F21/62—Protecting access to data via a platform, e.g. using keys or access control rules
  • G06F21/6218—Protecting access to data via a platform, e.g. using keys or access control rules to a system of files or objects, e.g. local or distributed file system or database
  • G06F21/6245—Protecting personal data, e.g. for financial or medical purposes
  • G06F21/6254—Protecting personal data, e.g. for financial or medical purposes by anonymising data, e.g. decorrelating personal data from the owner's identification
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
  • H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
  • H04L9/0861—Generation of secret information including derivation or calculation of cryptographic keys or passwords
  • H04L9/0866—Generation of secret information including derivation or calculation of cryptographic keys or passwords involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics

Definitions

• the present invention relates to a method of linking together sets of information relating to the same person. It also relates to information and central equipment provided for the implementation of this method and a system for chaining together sets of information stored in databases that uses this linking method and a computer program.
• the person identifier number (PIN or PIN for Personal Identification Number) is usually used for this purpose.
• PIN Personal Identification Number
• the person identifier numbers associated with the sets of information collected by the different remote devices are compared with each other and, as soon as two numbers are identical, the associated sets are related because they are related to the same person.
• This type of method of linking sets of information can not be implemented as simply in practice because it is not possible to leave any equipment the possibility, on the one hand, to be able to put in relation confidential information relating to the same person and, secondly, to go back to the identity of that person.
• the problem solved by the present invention is to define a method which makes it possible to relate together sets of confidential information of a person, in particular for purposes of statistical exploitation while preserving the anonymity of these people.
• the hash function transforms the person ID number into a single, reduced-length hash value called a fingerprint.
• This fingerprint serves to quickly identify a person without being able to go back to his ID number and thus to his identity.
• This fingerprint is often also called anonymous ID number.
• a hash function is defined so that the probability that two person ID numbers have the same fingerprint is very small.
• the hash function is not applied directly to the person identifier number but to a code formed by the concatenation of a prefix (sometimes called a hash key) and this identifier number. belongs to nobody.
• This solution avoids any so-called dictionary attack.
• a first piece of equipment which has collected sets of information relating to a person, obtains, from a prefix, a particular code for each person whose sets of information have been collected.
• a second device which is not aware of this prefix, can not regenerate this code from the identifier number of this person because he does not know this prefix. This second equipment can not therefore obtain a fingerprint relative to an ID number of a person that is identical to that generated by the first equipment and can not go back to the identity of this person.
• This type of method therefore imposes the use by the information equipment of the same prefix each time the sets of information collected by these information equipment must be put in relation to each other.
• This constraint goes against the limitation of fraudulent access by remote information equipment to the collection of information sets because it is sufficient for this information equipment to know this prefix to access (by dictionary attack) sets of information collected by all information facilities that use this prefix.
• This encryption function allows equipment that has collected sets of information to be able to protect their access to any other remote device by keeping the encryption key secret. Access is thus restricted even to equipment that uses the same encryption key.
• This encryption function can also be used to secure the transmissions between equipments since, for example, a person identification number must be transmitted by a device, for example a collector, to another equipment, for example central. Again access to fingerprints of person ID numbers is limited to equipment that knows the encryption key used.
• the present invention relates to a method of relating together sets of information relating to the same person among a plurality of sets of information relating to several persons, each set of information associated with a person ID number imprint from a person ID number.
• this method comprises the following steps performed in the or each piece of information equipment hosting the databases in which the said sets of information are stored:
• the first key which depends on the person identification number from which the fingerprint is issued, in order to obtain an encrypted fingerprint
• Double encryption (of the fingerprint and the first key) makes it possible to increase the robustness of the process against possible dictionary attacks because only the knowledge of these two keys (first and second) makes it possible to go back to the fingerprint of person ID number. This means that only duly authorized equipment can access the fingerprint used to link sets of information. Thus, from the knowledge of these two keys, the process finds fingerprints and uses them to link sets of information, for example for statistical purposes.
• the first key is the result of the application of a hash function on a person identifier number fingerprint.
• This embodiment further increases the security of access to the person ID numbers because it introduces a second hashing step in the method that is related to the person ID number.
• the hash function used for these two hash functions is preferably the same which facilitates the implementation of the method compared to the use of different hashing methods, on the one hand, to "anonymize” the number of person identifier and, secondly, to "obtain the first key from a person ID number.
• a fingerprint associated with a set of information is the result of the application of a hash function on a code obtained by concatenation of a prefix followed by a person identifier number.
• the first key is a public key of an asymmetric encryption method.
• This embodiment makes it possible to have different keys for encryption and decryption, which increases the communication security of the encryption keys between devices.
• the invention also relates to a computer program, which can be stored on a medium and / or downloaded from a communication network, in order to be read by a computer system or a processor.
• This computer program includes instructions for implementing either the steps of the aforementioned method that are implemented in information equipment, or the process steps that are implemented in a central equipment, when said program is executed by the computer system or the processor.
• the invention also relates to storage means comprising such a computer program.
• the present invention relates to information equipment which comprises means for implementing the steps of encryption and transmission of the method and a center equipment which comprises means for implementing the steps of decryption and linking the process.
• Fig. 1 is a diagram of the steps of the method of relating together sets of information relating to the same person according to the present invention.
• Fig. 2 is a diagram illustrating a system for chaining sets of information relating to persons using the method of FIG. 1.
• FIG. 3 schematically illustrates the architecture of the communications equipment implementing the method of FIG. 1.
• FIG. 1 is schematically represented a diagram of the steps of the method according to the invention of linking together sets of information relating to the same person among a plurality of sets of information relating to several people. These steps are implemented, on the one hand, in an information equipment Ei and, on the other hand, in a central equipment Ec. Each information device is intended to store a set of information that is associated with a fingerprint issued from a PIN number. Two sets of information are related, according to the method, when the fingerprints associated with them correspond or even are identical. This association is performed in the central equipment Ec after the one has received from at least one equipment Ei an encrypted associated fingerprint and a first key encrypted by a second key, as explained below.
• a fingerprint of person ID numbers also called simply fingerprint, associated with a set information, and noted DH (NIP) is the result of applying a hash function on a PIN person ID number.
• a DH (NIP) fingerprint is the result of the application of a hash function on a code obtained by concatenation of a prefix followed by a PIN number.
• a fingerprint denoted DH (NIP)
• NIP DH
• NIP hash function
• This variant is particularly effective in limiting the possibility for equipment involved during a statistical analysis of the information collected by different equipment to be able to go up to the anonymized person identification number because only a limited number of equipment can know the first prefix and an even more limited number can know both prefixes.
• the hash function used implements an algorithm of the SHA (Secure Hash Algorithm) family that can be found for example on the site (http // en.wikipedia.org / wiki / SHA_hash unctions).
• SHA Secure Hash Algorithm
• the method further includes a step 3 of encrypting each DH (NIP) fingerprint with a key lk.
• This key lk called the first key, is obtained in step 2 of the method from the PIN person identifier number from which the DH (NIP) fingerprint is issued or directly from the DH fingerprint (PIN ) as shown in FIG. 1, for example, by applying a hash function.
• the method further comprises a step 4 of encrypting the first key lk with another key Pw, said second key.
• Steps 3 and 4 are implemented in an information equipment Ei.
• the method further comprises, implemented in a central equipment Ec, a decryption step 5, from the encrypted key C (Pw, lk) transmitted by an information device Ei, of the first key with the second key Pw and a decryption step 6, from the transmitted encrypted footprint C (lk; DH (NIP)) by the same information equipment Ei, the identifier number DH (NIP) with the first key lk obtained after decryption in step 5.
• Fig. 2 is a diagram illustrating a system for chaining sets of information relating to persons using the method of FIG. 1.
• each information equipment E i has collected sets of information relating to J persons identified by their personal identifier numbers NIPj and therefore by their fingerprints DH (NIPj).
• the equipment El respectively E2, knows, beforehand, a first encryption key denoted 1k1, respectively lk2, and a second key Pw1, respectively Pw2.
• the central equipment EC knows, beforehand, the two keys Pwl and Pw2.
• the equipment El does not know the key lk2 nor the key Pw2 and in the same way the equipment E2 does not know either the key 1k1 or the key PW1 and this in order to secure the system against dictionary attacks .
• Two pieces of information Ei can know and use the same key PWi. This is the case, for example in the field of health, where the sets of information of people are collected by two pieces of information for the same epidemiological study for example which is associated with a single specific PWi key. However, even in this case, two devices Ei can never know the encryption key lki used by another remote device.
• an information equipment Ei Once an information equipment Ei has collected its information sets Ei, it transmits to the central equipment EC the associated encrypted footprint C (lki; DH (NIPj)) to each of these sets of information.
• This encrypted footprint is thus obtained, according to an embodiment of the method explained above, by hashing the PIN number and then encrypting by means of the key lki. Other methods for obtaining the impression are of course possible without departing from the scope of the present application.
• the sets of information remain, in turn, stored by the information equipment Ei who collected them.
• the central equipment EC is then able, for each of these sets of information to decrypt each first key lki received from a second key Pwi, known beforehand, and then decrypt each encrypted footprint C (lki; NIPj)) received from a first key lki thus decrypted and thus obtain the fingerprint DH (NIPj).
• the central equipment EC is then able to retrieve the fingerprints of person identifier numbers DH (NIPj) which are associated with the different sets of information transmitted by the equipment Ei, to compare these number fingerprints with each other. identifying a person and connecting two sets of information to each other when their associated DH ID (NIPj) fingerprints match or are identical.
• the advantage of this method is to allow the chaining of sets of information that are stored in information equipment comprising remote databases and which are related to the same person while ensuring the confidentiality of this information.
• Each piece of information equipment Ei will store the information sets of each person with a PIN person identifier number and create an associated encrypted fingerprint C (lki; DH (NIPj)) of its own. It is therefore impossible for equipment to decrypt and thus find the person ID numbers and thus find the person who is associated with this information dictionary attack.
• the EC central equipment that knows the decryption keys could go back to the identities of the people from the encrypted person ID number fingerprints but could not make the link between these people and the sets of information collected because these Sets of information remain stored on the information equipment Ei which collected them and are therefore not accessible to this central equipment EC.
• the first key lki is a public key of an asymmetric encryption method.
• This embodiment makes it possible to have different keys for encryption and decryption, which increases the security of the encryption method because the public key (corresponding to a key Pwi) is then known only equipment Ei which in need to encrypt their fingerprints of person ID numbers.
• the decryption of the collected information sets that are stored by the different information equipment Ei is then possible only if these devices know the private key that corresponds to the public key Pwi and encrypted person identifier numbers fingerprints received by the EC equipment are then decrypted by this equipment only if he knows this private key.
• This embodiment therefore prevents information equipment Ei from being able to exchange decryption keys and thus facilitates access control to these decryption keys compared to the use of secret keys.
• the time to encrypt the person ID numbers is relatively small and the encryption / decryption of these numbers is not a predominant criterion, it is preferable to use this embodiment rather than a symmetric key encryption method.
• Fig. 3 schematically illustrates the architecture of information equipment Ei or central equipment implementing the method of FIG. 1.
• the communication equipment 300 comprises, connected by a communication bus 306:
• processors a processor, micro-processor, microcontroller (denoted ⁇ ) or CPU (Central Processing Unit in English or Central Processing Unit in French) 301;
• Random Access Memory in English or Random Access Memory in French
• a 305 medium storage drive such as a SD card reader (Secure Digital Card in English or Secured Digital Card in French);
• interface means 303 with a communication network, such as for example an Internet-type network;
• human-machine interface means 304 allowing, for example, to manage a touch screen and / or a set of keys.
• the microcontroller 301 is capable of executing instructions loaded into the RAM 307 from the ROM 302, an external memory (not shown), a storage medium, such as an SD card or the like, or a communication network. When the device 300 is turned on, the microcontroller 300 is able to read instructions from RAM 307 and execute them. These instructions form a computer program that causes the implementation by the microcontroller 301 of all or part of the methods described below in relation to FIGS. 1 and 2. All or part of the methods described above in relation to FIGS.
• 1 and 2 may be implemented in software form by executing a set of instructions by a programmable machine, such as a DSP (Digital Signal Processor in English or Digital Signal Processing Unit in French) or a microcontroller, such as the microcontroller 301, or be implemented in hardware form by a machine or a dedicated component, such as an FPGA (Field-Programmable Gate Array in English or Programmable Gate Matrix on Field in French) or an ASIC (Application-Specific Integrated Circuit in English or Integrated Circuit Specific to an Application in French).
• a programmable machine such as a DSP (Digital Signal Processor in English or Digital Signal Processing Unit in French) or a microcontroller, such as the microcontroller 301, or be implemented in hardware form by a machine or a dedicated component, such as an FPGA (Field-Programmable Gate Array in English or Programmable Gate Matrix on Field in French) or an ASIC (Application-Specific Integrated Circuit in English or Integrated Circuit Specific to an Application in French).
• the microcontrollers 301 and the RAMs 307 and ROM 302 cooperate with each other to form encryption means of a fingerprint ID of a person identifier DH (NIP) with a key lk, and to form encryption means of the first key lk with another key Pw.
• NIP person identifier DH
• the microcontrollers 301 and the RAMs 307 and ROM 302 cooperate with each other to form means for decrypting a first key which depends on a fingerprint of the person identification number with another key, and to form means for decrypting an identifier number fingerprint with the first key thus decrypted.
• These encryption means are required for the implementation of the method by the communication equipment 300.
• the microcontrollers 301 and the RAMs 307 and ROMs 302 also cooperate with each other to form means for connecting sets of information relating to the same person when the associated person ID numbers are associated. to each of these sets are identical.

Landscapes

• Engineering & Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Health & Medical Sciences (AREA)
• Bioethics (AREA)
• General Health & Medical Sciences (AREA)
• Theoretical Computer Science (AREA)
• Databases & Information Systems (AREA)
• Computer Hardware Design (AREA)
• Software Systems (AREA)
• Physics & Mathematics (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Medical Informatics (AREA)
• Power Engineering (AREA)
• Storage Device Security (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=46880739

Family Applications (1)

Country Status (3)

Family Cites Families (4)

• 2011
  • 2011-10-28 FR FR1159836A patent/FR2982104B1/fr active Active
• 2012
  • 2012-09-24 EP EP12761637.3A patent/EP2772003A1/de not_active Withdrawn
  • 2012-09-24 WO PCT/EP2012/068789 patent/WO2013060539A1/fr not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events