METHOD FOR THE SECURED RECORDING OF DATA, CORRESPONDING DEVICE AND PROGRAM

• US 20170132435A1
• Filed: 11/04/2016
• Published: 05/11/2017
• Est. Priority Date: 11/06/2015
• Status: Active Grant

• Current Assignee: Banks And Acquirers International Holding
• Original Assignee: Ingenico Group
• Inventors: ROLIN, Christian, MULLER, Laurent, BELLAHCENE, Mohammed, ROYER, Jessica, POMMARET, Jean-Christophe
• Granted Patent: US 10,318,766 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions

Abstract

A method for the secured recording of data, implemented in a data-recording device having a first non-secured memory and a second secured memory, is disclosed. The method has the steps of: obtaining a derived key corresponding to the data in the second memory from a root key recorded in the second memory; encrypting data using the derived key, delivering encrypted data; recording the encrypted data in the first memory; determining a hash imprint of said data; recording said hash imprint in a hash file recorded in the first memory; recording a general hash imprint, representing the content of the hash file comprising said hash imprint, in the second memory; and eliminating the data in the second memory.

Claims

1. Method for the secured recording of data, implemented in a data-recording device comprising a first non-secured memory and a second secured memory, the method comprising the following steps:

obtaining a derived key corresponding to the data recorded in the second memory from a root key recorded in the second memory;

encrypting data using the derived key, delivering encrypted data;

recording the encrypted data in the first memory;

determining a hash imprint of said data;

recording said hash imprint in association with the data in a hash file recorded in the first memory;

recording a general hash imprint, representing the content of the hash file comprising said hash imprint, in the second memory; and

eliminating the data in the second memory subsequently to said recording of encrypted data in the first memory.

2. Method according to claim 1 wherein, after it is obtained, the derived key is recorded in the second memory, the method furthermore comprises a step for eliminating the derived key from the second memory after the encryption of said data.

3. Method according of claim 1, wherein the root key is generated randomly in the data-recording device.

4. Method according to claim 1 wherein, during the step for obtaining, the derived key is obtained from:

a user identifier representing a user of the data-recording device; and

a data identifier.

5. Method according to claim 4, wherein, during said recording of the encrypted data, said encrypted data are recorded in the first memory in the form of an encrypted file to which a file name is assigned comprising the user identifier and the data identifier.

6. Method according to claim 1 comprising, after said recording of the hash imprint in the hash file, a recording of a copy of the hash file in a secured back-up memory of the data-recording device.

11. Computer program comprising instructions for the execution of the steps of a method for the secured recording of data according to claim 1, when said program is executed by a computer.

7. Method for the secured retrieval of data, implemented in a data-recording device comprising a first non-secured memory and a second secured memory, the method comprising:

a verification of the integrity of a hash file recorded in the first memory from a general hash imprint recorded in the second memory; and

when the hash file is detected as having integrity, the method furthermore comprises, upon reception of a request for access to data, the following steps;

obtaining a derived key corresponding to encrypted data recorded in the first memory, from a root key recorded in the second memory;

decrypting encrypted data using the obtained derived key so as to retrieve said data;

recording said data in the second memory;

determining the hash imprint of said data;

verifying the integrity of the data recorded in the second memory by comparing the hash imprint determined for the data with a hash imprint recorded in the hash file in association with said data; and

authorization of access to the data in the second memory in response to said access request, only if the data has been determined as having integrity.

8. Method according to claim 7, comprising a step for obtaining a user identifier representing a user of the data-recording device and a data identifier, in which the derived key is obtained from the root key by using the user identifier and the data identifier.

9. Method according to claim 7 comprising, subsequently to an access to the data:

encrypting data using the derived key, delivering encrypted data;

recording the encrypted data in the first memory;

determining the hash imprint of said data;

recording said hash imprint in association with the data in the hash file recorded in the first memory;

recording the general hash imprint, representing the content of the hash file comprising said hash imprint, in the second memory; and

eliminating the data in the second memory subsequently to said recording of encrypted data in the first memory.

10. Method according to claim 7, further comprising the following steps after an access by the user to the data in the second memory:

determining a second hash imprint of said data following said access; and

comparing said second hash imprint with the hash imprint recorded in the hash file in association with the data, in order to detect whether the data have been modified during said access;

wherein, only if it has been detected that the data have been modified during said access, the method further comprising;

encrypting data using the derived key, delivering encrypted data;

recording the encrypted data in the first memory;

determining the hash imprint of said data;

recording said hash imprint in association with the data in the hash file recorded in the first memory;

recording the general hash imprint, representing the content of the hash file comprising said hash imprint, in the second memory; and

eliminating the data in the second memory subsequently to said recording of encrypted data in the first memory.

12. Computer program comprising instructions for the execution of the steps of a method for the secured retrieval of data according to claim 7, when said program is executed by a computer.

13. Data-recording device comprising:

a first non-secured memory;

a second secured memory;

an obtaining module configured to obtain a derived key corresponding to data recorded in the second memory from a root key recorded in the second memory;

an encryption module configured for the encryption, using the derived key, of said data so as to deliver encrypted data;

a first recording module configured for the recording of the encrypted data in the first memory;

a determining module configured to determine a hash imprint of said data;

a second recording module configured for the recording of said hash imprint, in association with the data, in a hash file recorded in the first memory;

a third recording module configured for the recording, in the second memory, of a general hash imprint representing the content of the hash file comprising said hash imprint; and

an elimination module configured to eliminate the data in the second memory after said recording of the encrypted data in the first memory.

14. Device according to claim 13, wherein:

the obtaining module is configured for the recording, in the second memory, of said derived key obtained from the root key; and

the elimination module is configured to eliminate the derived key recorded in the second memory after the encryption of said data by the encryption module.