Methods and systems for verifying the validity of digital content

Abstract

The present invention relates to the technical field of validation and authentication of digital data, such as digital documents, in particular the validation of the digital content of a digital message, such as an operation that is authenticated by an entity that a controller authorizes to perform that operation.

Claims

1. A method for validating the digital content of a digital message M received by a device DB controlled by a controller B via a communication network CN, A device DA controlled by controller A comprises a processing unit CPU (A) having a memory storing the digital message M, and a communication module CM (A) configured to transmit and receive data via the communication network CN. The device DB comprises a processing unit CPU (B) having a memory storing an aggregated digital signature ADS, and a communication module CM (B) configured to transmit and receive data via the communication network CN, wherein the aggregated digital signature ADS is calculated by applying a one-way accumulator to a plurality of digital signatures, and the plurality of digital signatures include a digital signature x (A) of authorization data AD (A) calculated by a one-way function. The digital message M includes authorization data AD(A) indicating that the controller A of the device DA is authorized by controller C to perform operation Op using the controller of the device that receives the digital message M, The digital message M also includes a verification key VK(A) originating from the controller C, and together with the authorization data AD(A), the verification key VK(A) is used to compute a candidate aggregate digital signature cADS, and the processing unit CPU(B) is configured to compare the candidate aggregate digital signature cADS with the aggregate digital signature ADS stored in the memory of the processing unit CPU(B) of the device DB. The method described above is The steps include: (100b, 200) the communication module CM(B) of the device DB receives the digital message M; The processing unit CPU (B) of the device DB extracts the permission data AD (A) contained in the digital message M (201), The steps include: (400) the communication module CM(B) of the device DB receiving an authentication SA from the communication module CM(A) of the device DA, The process includes the step in which the processing unit CPU (B) of the device DB verifies the certified SA (400b), The processing unit CPU (B) of the device DB is The verification key VK(A) contained in the digital message M is extracted (204), The processing unit CPU (B) calculates a candidate digital signature cx(A) of the authorization data AD(A) using the one-way function programmed in (203), The system is configured to calculate the candidate aggregate digital signature cADS from the verification key VK(A) and the calculated candidate digital signature cx(A) of the authorization data AD(A) (205), The processing unit CPU (B) of the device DB checks (206) whether the aggregate digital signature ADS stored in memory matches the candidate aggregate digital signature cADS (207), and only if there is a positive verification of the certified SA and a positive match between the candidate aggregate digital signature cADS and the aggregate digital signature ADS, the processing unit CPU (B) of the device DB sends an instruction (500) via the communication module CM (B) that the controller A is actually authorized by the controller C to perform the operation Op (500a), method.

2. The memory of the processing unit CPU (A) of the device DA is configured to store a private key PrK (A), and the processing unit CPU (A) is configured to sign data using the private key PrK (A). The processing unit CPU (B) of the device DB is configured to verify the signed data using the corresponding public key provided by the communication module CM (B). The digital message M further includes a public key PuK(A) which corresponds to the private key PrK(A) and is recognized by controller C as being owned by controller A, The aforementioned certified SA is certified data signed using the aforementioned private key PrK(A), Prior to the step in which the processing unit CPU (B) of the device DB verifies the certified SA (400b), the processing unit CPU (B) of the device DB extracts the public key PuK (A) from the digital message M (202), The step of verifying the accredited SA (400b) includes the verification of the accredited SA by the processing unit CPU (B) of the device DB using the public key PuK (A), The method according to claim 1.

3. The communication network CN includes a short-range wireless communication network NFCN, the communication module CM(A) is configured to transmit and receive data via the short-range wireless communication network NFCN, the communication module CM(B) is configured to transmit and receive data via the short-range wireless communication network NFCN, and the short-range wireless communication network NFCN enables communication between the communication module CM(A) and the communication module CM(B) when the distance between them is less than 50 cm. The method according to claim 1.

4. The device DA comprises a display module DD(A) and an optical reader module OR(A), the device DB comprises a display module DD(B) and an optical reader module OR(B), the step of receiving the digital message M by the communication module CM(B) of the device DB includes the step of reading an optically readable representation of a graphical data block GDB displayed by the display module DD(A) with the optical reader module OR(B), the graphical data block GDB includes a digital mark DM, the digital mark DM includes an encoded version EAD(A) of the authorization data AD(A) and an encoded version EVK(A) of the verification key VK(A), the extraction of the authorization data AD(A) includes decoding the encoded authorization data EAD(A), and the extraction of the verification key VK(A) includes decoding the encoded verification key EVK(A). The method according to claim 1.

5. The optically readable representation of the graphical data block GDB includes a digital representation of graphical symbols from a specific finite set of graphical symbols, and the digital representation of graphical symbols is configured to encode the digital mark DM and the machine-readable error-corrected data block. The method according to claim 4.

6. The memory of the device DB stores a private key Prk(B) and a corresponding public key PuK(B) which are certified by controller C as being owned by controller B, the processing unit CPU(B) of the device DB is configured to sign data using the private key PrK(B), and the processing unit CPU(A) of the device DA is configured to verify the signed data using the corresponding public key via the communication module CM(A). The method according to claim 1.

7. Prior to the step of receiving the certified SA from the communication module CM(A) via the communication module CM(B) (400), the device DB includes the step of transmitting a secret generated by the device DB from the communication module CM(B) to the communication module CM(A) (300), wherein the secret is configured to generate the certified SA. The method according to claim 1.

8. Prior to the step of receiving the certified SA from the communication module CM(A) by the communication module CM(B) (400), the device DB transmits a secret generated by the device DB from the communication module CM(B) to the communication module CM(A) (300), wherein the secret is configured to generate the certified SA. The method according to claim 2.

9. The secret is configured to be signed by the processing unit CPU (A) using the private key PrK (A) in order to generate the certified SA (300a), The method according to claim 8.

10. The step of transmitting the secret (300) includes the step of displaying an optically readable representation of a graphic element encoded with the secret and configured to be read by the optical reader module OR(A) of the device DA, by the display module DD(B) of the device DB. The method according to claim 7.

11. Before or after receiving the digital message M, the controller B receives a digital document, and the certifying SA includes a signature on the content of the digital document, and the signature is generated by the processing unit CPU (A) by signing the content using the private key PrK (A) stored in the memory of the processing unit CPU (A). The method according to claim 1.

12. The digital message M is authenticated by the controller C (10), and the method includes a step of verifying that the digital message M is authenticated by the controller C (10b) by the processing unit CPU (B) of the device DB before the step of extracting the authorization data AD(A) contained in the digital message M by the processing unit CPU (B) of the device DB (201), and only in the case of a positive verification that the digital message M is authenticated by the controller C (10) does the processing unit CPU (B) of the device DB extract the authorization data AD(A) contained in the digital message M (201). The method according to any one of claims 1 to 2.

13. A system for validating the digital content of a digital message M received by a device DB controlled by a controller B via a communication network CN, wherein the system A device DA is controlled by a controller A which includes a processing unit CPU (A) having a memory storing the digital message M, and a communication module CM (A) configured to transmit and receive data via the communication network CN. The device DB comprises a processing unit CPU (B) having a memory storing an aggregated digital signature ADS, and a communication module CM (B) configured to transmit and receive data via the communication network CN, wherein the aggregated digital signature ADS is calculated by applying a one-way accumulator to a plurality of digital signatures, and the plurality of digital signatures include a digital signature x (A) of authorization data AD (A) calculated by a one-way function. The digital message M includes authorization data AD(A) indicating that the controller A of the device DA is authorized by controller C to perform operation Op using the controller of the device that receives the digital message M, The digital message M also includes a verification key VK(A) attributable to the controller C, and together with the authorization data AD(A), the verification key VK(A) is used to compute a candidate aggregate digital signature cADS, and the processing unit CPU(B) is configured to compare the candidate aggregate digital signature cADS with the aggregate digital signature ADS stored in the memory of the processing unit CPU(B) of the device DB. The communication module CM(B) of the device DB is configured to receive the digital message M (100b, 200), The processing unit CPU (B) of the device DB is configured to extract the permission data AD (A) contained in the digital message M (201), The communication module CM(B) of the device DB is configured to receive an authentication SA from the communication module CM(A) of the device DA (400), The processing unit CPU (B) of the device DB is configured to verify the certified SA (400b), The processing unit CPU (B) of the device DB is The verification key VK(A) contained in the digital message M is extracted (204), The processing unit CPU (B) calculates a candidate digital signature cx(A) of the authorization data AD(A) using the one-way function programmed in (203), The system is configured to calculate the candidate aggregate digital signature cADS from the verification key VK(A) and the calculated candidate digital signature cx(A) of the authorization data AD(A) (205), The processing unit CPU (B) of the device DB is configured to check (207) whether the aggregate digital signature ADS stored in memory (206) matches the candidate aggregate digital signature cADS, and only if there is a positive verification of the certified SA and a positive match between the candidate aggregate digital signature cADS and the aggregate digital signature ADS, the processing unit CPU (B) of the device DB is configured to send (500) an instruction via the communication module CM (B) that controller A is actually authorized by controller C to perform the operation Op (500a). system.

14. The memory of the processing unit CPU (A) of the device DA is configured to store the private key PrK (A), and the processing unit CPU (A) is configured to sign data using the private key PrK (A). The processing unit CPU (B) of the device DB is configured to verify the signed data using the corresponding public key provided by the communication module CM (B). The digital message M further includes a public key PuK(A) which corresponds to the private key PrK(A) and is recognized by controller C as being owned by controller A, The aforementioned certified SA is certified data signed using the aforementioned private key PrK(A), The processing unit CPU (B) of the device DB is configured to extract the public key PuK (A) from the digital message M (202), The processing unit CPU (B) of the device DB is configured to verify the certified SA using the public key PuK (A) (400b). The system according to claim 13.

15. Device DA comprises a display module DD(A) and an optical reading device module OR(A), and device DB comprises a display module DD(B) and an optical reading device module OR(B), wherein the display module DD(A) of device DA is configured to display an optically readable representation of a graphical data block GDB, and the optical reading device module OR(B) of device DB is configured to read the optically readable representation of the graphical data block GDB, and the graphical data block GDB is digital The digital mark DM includes an encoded version EAD(A) of the authorization data AD(A) and an encoded version EVK(A) of the verification key VK(A), the processing unit CPU(B) of the device DB is configured to extract the authorization data AD(A) by decoding the encoded authorization data EAD(A), and the processing unit CPU(B) of the device DB is configured to extract the verification key VK(A) by decoding the encoded verification key EVK(A). The system according to any one of claims 13 to 14.

16. A use of the system for validating the digital content of a digital message M according to claim 13, for verifying the validity of the execution of an operation Op by a device DB, wherein the operation Op is executed by a device DA, The device DB is provided and controlled in storage room B, the device DA is provided and controlled in robot A, and the operation Op is related to the robot A retrieving a specific product located inside storage room B, or The device DB is provided and controlled by computer B, the device DA is provided and controlled by smartphone A, and the operation Op relates to the smartphone A transmitting a set of data SeD(A) to computer B, or The device DB is provided for and controlled by medical device B, the device DA is provided for and controlled by nurse A, and the operation Op relates to nurse A using medical device B to inject a specific drug into a specific patient, or Device DB is provided to and controlled by citizen B, device DA is provided to and controlled by police officer A, and operation Op is related to police officer A entering citizen B's house to search for evidence, or The device DB is provided to and controlled by citizen B, the device DA is provided to and controlled by public official A, and the operation Op is related to public official A issuing and signing an official digital document. Use of the aforementioned system.

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