Method and apparatus for sending and receiving consumption data and implementing the method

Abstract

The present invention relates to a method for sending consumption data, a method for receiving the same, and an apparatus for implementing the methods. A sending method for a meter to send consumption data to a meter data management system is described. The meter obtains (S301) consumption data, which is obtained by metering software. The meter generates (S302) a tag based on a triple, which includes the serial number of the meter, a cyclic redundancy code calculated based on the metering software, and a certificate number proving that the meter is authorized for consumption settlement. Then, the meter encrypts (S304) the tag with a private key known only to the meter to obtain a signature. Finally, the meter sends (S306) a frame to the consumption data management system, and the frame includes the identifier of the meter, the obtained consumption data, and the signature.

Description

Technical Field

[0001] At least one embodiment relates to a sending method for a meter to send consumption data to a system for managing the consumption data. At least one other embodiment relates to a receiving method for the consumption data. Devices for implementing the sending method and the receiving method are also described. Background Art

[0002] Known smart meters, such as electricity meters, heat meters or fluid meters, such as gas meters or water meters, include communication interfaces that enable an automated management system to remotely collect consumption data. For example, these smart meters include (one or more) communication interfaces of the CPL (acronym for "Courant Porteur en Ligne", meaning power line communication) type and / or radio type. The meter then sends the consumption data of the customer through these communication interfaces, for example in the form of frames, so as to upload these consumption data to an information system that processes them in a centralized manner at regular or irregular intervals. The information system uses these consumption data, in particular for the settlement operations of service providers with consumer customers. To this end, the meter uses metering methods or software to generate these consumption data based on measurements that should comply with legal metrology requirements. Metrology is the science of measurement and its applications. It includes all theoretical and practical aspects of measurement. Legal metrology is a part of metrology that relates to activities arising from legal requirements and applies to measurements, measurement units, and measuring instruments. Therefore, legal metrology also includes the infrastructure necessary for establishing legal requirements, verifying / evaluating the compliance of regulated products and regulated activities, monitoring regulated products and regulated activities, and the traceability of installed regulated measurements and measuring instruments. For example, Directive 2014 / 32 / EU, known by the acronym MID for "Measuring Instruments Directive", regulates the placing on the market of most measuring instruments covered by legal metrology, such as electricity meters, gas meters, heat meters or water meters. This directive sets out the technical requirements applicable to the design and production of these measuring instruments. Therefore, only meters certified by MID can be used for settlement. In the certification, the certification body assigns a MID certificate number to the meter.

[0003] The consumption data for settlement should be free of any errors to avoid possible disputes related to price disputes. Errors may particularly come from the modification of the consumption data during the sending of the frame including the consumption data. Errors may also come from the meter using an incorrect version of the metering software, such as an outdated version.

[0004] Currently, in the case of a dispute between a customer and a service provider regarding the price of consumed data, one solution is for the service provider to send an operator to the customer's premises to directly read the consumed data on the customer's meter display. Such a solution is not satisfactory because it requires, on the one hand, the meter to be equipped with a display and, on the other hand, the operator to travel to the customer's home, both of which incur costs.

[0005] It is desirable to mitigate these various drawbacks of the prior art. In particular, it is desired to propose a method for sending consumed data that is reliable and, in particular, enables proof that the consumed data received by the information system indeed comes from the certified software of the meter from which it should originate and that it was indeed generated by the correct version of the metering software. Summary of the Invention

[0006] At least one embodiment relates to a method for a meter to send consumed data to a meter data management system. The method includes the following steps implemented by the meter:

[0007] - Obtaining consumed data, which is obtained by metering software;

[0008] - Generating a mark (empreinte) based on a triple, the triple including the serial number of the meter, a cyclic redundancy code calculated based on the metering software, and a certificate number proving that the meter is authorized for consumption settlement;

[0009] - Encrypting the mark with a private key known only to the meter, and the encrypted mark then becomes a signature; and

[0010] - Sending a frame to the system for managing the consumed data, the frame including the identifier of the meter, the obtained consumed data, and the signature.

[0011] The described method advantageously enables proof that the received consumed data indeed comes from the correct meter, i.e., the meter that should have sent the consumed data, and enables proof that the consumed data was obtained by the correct version of the metering software.

[0012] According to a particular embodiment, generating the mark includes applying a hash function to the triple.

[0013] According to a particular embodiment, the hash function belongs to a group of hash functions including the following:

[0014] - SHA-224 of the SHA-3 family;

[0015] - SHA-256 of the SHA-3 family;

[0016] - SHA-384 of the SHA-3 family;

[0017] - SHA-512 of the SHA-3 family;

[0018] - SHA-224 of the SHA-2 family;

[0019] - SHA-256 of the SHA-2 family;

[0020] - SHA-384 of the SHA-2 family;

[0021] - SHA-512 of the SHA-2 family;

[0022] - MD-4;

[0023] - MD-5; and

[0024] - SHA-1.

[0025] According to a specific embodiment, encrypting the tag with a private key known only to the meter includes applying asymmetric elliptic curve encryption.

[0026] According to a specific embodiment, the consumption data is consumption data of electricity, gas, gasoline, heat energy or water.

[0027] At least one embodiment relates to a receiving method for a system for managing consumption data to receive the consumption data. The system for managing the consumption data stores, in a memory, a triple for each meter in a group of meters, the triple including the serial number of the meter, the cyclic redundancy code of the metering software, and the relevant certificate number proving that the meter is authorized for consumption settlement. The method includes the following steps implemented by the system for managing the consumption data:

[0028] - Receiving a frame including an identifier of a meter, consumption data, and a signature;

[0029] - Decrypting the signature with the public key associated with the meter identified by the identifier;

[0030] - Generating a tag based on the triple associated with the meter identified by the identifier in the memory;

[0031] - Comparing the decrypted signature and the generated tag, and sending an alarm signal if the two are not equal.

[0032] At least one embodiment relates to a method for a meter to send consumption data to a system for managing the consumption data. The system for managing the consumption data stores triples in a memory for each meter in a group of meters. The triples include the serial number of the meter, a cyclic redundancy code of the metering software, and a relevant certificate number proving that the meter is authorized for consumption settlement. The method includes the following steps implemented by the meter:

[0033] - Obtain consumption data, which is obtained by metering software;

[0034] - Generate a tag based on the triple, which includes the serial number of the meter, a cyclic redundancy code calculated based on the metering software, and a certificate number proving that the meter is authorized for consumption settlement;

[0035] - Encrypt the tag with a private key known only to the meter, and the encrypted tag then becomes a signature; and

[0036] - Send a frame to the system for managing the consumption data, the frame including the identifier of the meter, the obtained consumption data, and the signature.

[0037] The method further includes the following steps implemented by the system for managing the consumption data:

[0038] - Receive the frame;

[0039] - Decrypt the signature with the public key associated with the meter identified by the identifier;

[0040] - Generate a tag based on the triple associated with the meter identified by the identifier in the memory; and

[0041] - Compare the decrypted signature and the generated tag, and send an alarm signal if the two are not equal.

[0042] At least one embodiment relates to a meter configured to send consumption data to a system for managing the consumption data. The meter includes:

[0043] - A component for obtaining consumption data, which is obtained by metering software;

[0044] - A component for generating a tag based on a triple, which includes the serial number of the meter, a cyclic redundancy code calculated based on the metering software, and a certificate number proving that the meter is authorized for consumption settlement;

[0045] - A component for encrypting the tag with a private key known only to the meter, and the encrypted tag then becomes a signature; and

[0046] - A component for sending a frame to a system for managing the consumption data, the frame including the identifier of the meter, the obtained consumption data, and the signature.

[0047] At least one embodiment relates to a meter data management system that stores, in a memory, a triple for each meter in a group of meters, the triple including the serial number of the meter, the cyclic redundancy code of the metering software, and the relevant certificate number proving that the meter is authorized for consumption settlement. The meter data management system includes:

[0048] - A component for receiving a frame including the identifier of the meter, the consumption data, and the signature;

[0049] - A component for decrypting the signature with the public key associated with the meter identified by the identifier;

[0050] - A component for generating a tag based on the triple associated with the meter identified by the identifier in the memory; and

[0051] - A component for comparing the decrypted signature and the generated tag and sending an alarm signal if the two are not equal.

[0052] At least one embodiment relates to an automated management system configured to remotely collect consumption data. The automated management system includes at least one meter according to one of the foregoing embodiments and a meter data management system according to one of the foregoing embodiments.

[0053] At least one embodiment relates to a computer program product including instructions for implementing a sending method or a receiving method according to any one of the foregoing embodiments when the program is executed by a processor.

[0054] At least one embodiment relates to a storage medium storing a computer program including instructions for implementing a sending method or a receiving method according to any one of the foregoing embodiments when the program is executed by a processor. Description of the Drawings

[0055] The above and other features of the present invention will become clearer upon reading the following description of the embodiments, which is made in conjunction with the drawings, in which:

[0056] Figure 1 Schematically shows an automated management system according to a specific embodiment, which is configured to transcribe consumption data from a communicable measuring device;

[0057] Figure 2 Schematically shows an example of the hardware architecture of an intelligent meter of an automated management system according to a specific embodiment;

[0058] Figure 3 Schematically shows an example of the hardware architecture of a meter data management system according to a specific embodiment;

[0059] Figure 4 Shows a method for a meter to send consumption data according to a specific embodiment;

[0060] Figure 5 Shows the frame sent by the meter to the meter data management system;

[0061] Figure 6 Shows a method for a consumption data management system to receive consumption data according to a specific embodiment;

[0062] Figure 7 Shows a method for a meter to send consumption data according to a specific embodiment; and

[0063] Figure 8 Shows a method for a consumption data management system to receive consumption data according to a specific embodiment. Detailed Description

[0064] Therefore, Figure 1 Schematically shows an automation management system 100 in which the present invention can be implemented. The automation management system 100 is configured to transcribe consumption data from communicable measuring devices 140a and 140b, such as smart meters SM (short for "Smart Meters" in English). The smart meters SM 140a and 140b are, for example, electricity meters, gas meters, heat meters, or water meters, or meters for any other type of fluid (such as gasoline) whose consumption can be measured by metering software. These smart meters 140a and 140b have the ability to communicate with the information system SI 110 via radio transmission and / or CPL. The information system SI 110 includes a network head-end system HES (acronym for "Head-End System", meaning head-end system), a meter data management system MDMS (acronym for "Meter Data Management System"), and a key management system KMS (acronym for "Key Management System").

[0065] The role of the information system SI 110 is to monitor the measurement operations performed by the smart meters SM 140a and 140b. To this end, the information system SI 110 entrusts the management of the network to a data concentrator DC (acronym for "Data Concentrateur"). Figure 1Two DCs 120a, 120b are shown as examples. The automated management system 100 generally includes a plurality of such DCs, which send frames to the network head system HES.

[0066] Each system in the SI communicates with each other via a network ( Figure 1 not shown in the figure), such as a VPN-type private network or the Internet. The network head system HES exchanges data with the data concentrators DC 120a, 120b via the communication network NET 101. The communication network NET 101 is, for example, the Internet. In other embodiments, the communication network NET 101 is a wireless communication network, such as GPRS (General Packet Radio Service), UMTS (Universal Mobile Telecommunication System), LTE (Long-Term Evolution), NB-IoT (Narrowband Internet of Things), 2G, 3G, 4G or 5G.

[0067] Each data concentrator DC 120a, 120b manages the communication with a group of smart meters SM via the communication network LR_NET 102. The communication network LR_NET 102 is a CPL (Courant Porteur en Ligne) type communication network or a wireless communication network, such as a Long Range wireless network.

[0068] Preferably, the communication network LR_NET 102 is a low power wide area network LPWAN, such as according to LoRaWAN or NB-IoT technology. According to a variant, the smart meter SM can communicate with the data concentrator DC by using two different networks, such as a CPL network and a wireless network.

[0069] With the help of the communication network LR_NET 102, the data concentrator DC 120a communicates directly or indirectly (e.g., via a smart meter assigned the role of repeater REL) with the paired smart meters SM 140a, 140b.

[0070] Therefore, the data concentrator DC collects consumption data from the paired smart meters SM 140a, 140b and sends it to the information system SI 110 periodically, such as once a day or several times a day.

[0071] InFigure 1 In an implementation variant not shown, the smart meter SM can communicate directly with the SI 110 without going through the DC.

[0072] In the context of legal metrology, a cyclic redundancy code or CRC (acronym for "Cyclic Redundancy Code" in English) is calculated as per the regulations when generating the metrology software (CRC32 is calculated on 32 bits using a normalization polynomial). This cyclic redundancy code is integrated into the metrology software. The metrology software is verified and then sent an authentication to obtain MID authentication. Once the MID authentication is obtained, the authentication number is sent to the meter data management system MDMS, which then stores in memory the CRC code of the metrology software and the MID authentication number associated with the serial number of the meter concerned for each MID-authenticated meter.

[0073] Figure 2 An example of the hardware architecture of the smart meter 200 of the automation management system 100 according to a specific embodiment is schematically shown.

[0074] The smart meter 200 includes, connected by a communication bus 210: a processor or CPU (English "Central Processing Unit", meaning central processing unit) 201; a read-write memory RAM (English "Random Access Memory", meaning random access memory) 202; a read-only memory ROM (English "Read Only Memory"), such as a flash memory; a data storage device, such as a hard disk HDD (English "Hard Disk Drive", meaning hard disk drive), or a storage medium reader, such as an SD (English "Secure Digital", meaning secure digital) card reader 204; at least one input / output interface I / O 205, in particular a communication interface with the communication network LR_NET 102 and, in the case of direct communication with the SI, a communication interface with the communication network NET 101 if necessary.

[0075] The processor 201 is capable of executing instructions loaded into the RAM 202 from the ROM 203, an external memory (not shown), a storage medium such as an SD card, or a communication network (not shown). When the smart meter 200 is powered on, the processor 201 is capable of reading instructions from the RAM 202 and executing them. These instructions form a computer program that causes the processor 201 to implement the steps and methods described later in conjunction with Figure 4 the steps and methods described later.

[0076] later in conjunction with Figure 4All or part of the described steps and methods can thus be implemented in software by a programmable machine, such as a DSP (Digital Signal Processor) or a microcontroller, executing a set of instructions, or in hardware by a dedicated component (a chip), or a machine, or a set of dedicated components (a chipset), such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). Generally, the smart meter 200 includes electronic circuitry arranged and configured to implement the steps and methods described hereinafter in connection with Figure 4 the steps and methods.

[0077] Figure 3 An example of the hardware architecture of the meter data management system MDMS 300 of the automation management system 100 according to a particular embodiment is schematically shown.

[0078] The meter data management system MDMS 300 includes, connected by a communication bus 310: a processor or CPU (Central Processing Unit) 301; a read-write memory RAM (Random Access Memory) 302; a read-only memory ROM (Read Only Memory) 303, such as a flash memory; a data storage device, such as a hard disk HDD (Hard Disk Drive), or a storage medium reader, such as an SD (Secure Digital) card reader 304; at least one input / output interface I / O 305, which particularly includes a communication interface with the network NET.

[0079] The processor 301 is capable of executing instructions loaded into the RAM 302 from the ROM 303, an external memory (not shown), a storage medium such as an SD card, or a communication network (not shown). When the meter data management system MDMS 300 is powered on, the processor 301 is capable of reading instructions from the RAM 302 and executing them. These instructions form a computer program that causes the processor 301 to implement the steps and methods described hereinafter in connection with Figure 6 the steps and methods.

[0080] Hereinafter in connection with Figure 6All or part of the described steps and methods can thus be implemented in software by a programmable machine (such as a DSP (short for "Digital Signal Processor") or a microcontroller) executing a set of instructions, or in hardware by a dedicated component (a "chip") or a machine or a set of dedicated components (a "chipset"), such as an FPGA (short for "Field-Programmable Gate Array") or an ASIC (short for "Application-Specific Integrated Circuit"). Generally speaking, the metering data management system MDMS 300 includes electronic circuits arranged and configured to implement the steps and methods described hereinafter in conjunction with Figure 6 the steps and methods.

[0081] Figure 4 Shows a method of sending consumption data (denoted as Idx) by a meter according to a particular embodiment. The consumption data is, for example, the reading of an electricity meter, a water meter, etc.

[0082] The method starts at step S300.

[0083] In step S301, the meter obtains the consumption data by means of metering software.

[0084] In step S302, the meter generates a tag, denoted as HASH, based on a triple that includes the serial number of the meter, a cyclic redundancy code or CRC (the acronym for "Cyclic Redundancy Code") calculated based on the metering software used by the meter, and the MID certificate number assigned to the meter, which certifies that the meter is authorized for consumption settlement operations. For this purpose, a hash function is used, for example, a function of the SHA-2 family. A particular function is called the hash function H(.), in English "hash function": it calculates a digital tag based on the data provided as input, which is used to quickly identify the initial data. In other words, a given triple corresponds to a unique tag, i.e., the result of the hash function. Thus, for two different triples T1 and T2, the meter generates two tags S1 = H(T1) and S2 = H(T2), where S1 and S2 are different.

[0085] In one embodiment, the function H(.) is a function of the SHA-2 family, such as SHA-224, SHA-256, SHA-384 or SHA-512. In the case where the function H(.) is of the SHA-256 type, the resulting tag HASH consists of 256 bits. In the case where the function H is of the SHA-512 type, the resulting tag HASH consists of 512 bits. Other functions can be used, such as the SHA-3 function, the MD4 function, the MD5 function, the SHA-1 function, which are well known in the field of cryptography; these examples are clearly not restrictive.

[0086] In an implementation variant, an optional padding step is applied to the triple in order to obtain an integer number of bytes before applying the hash function H(.).

[0087] In step S304, the meter encrypts the generated tag with a private key known only to the meter. The encrypted tag is a signature and is denoted as HASH'. This private key is generated in advance by the meter based on its serial number. In a particular embodiment, the private key is generated by applying the "exclusive OR" operator between an N-bit random value specific to the meter and H(serial number), for example N = 256 and H() is the SHA-256 function, to obtain a 256-bit private key. The public key associated with this private key is known in particular to the key management system KMS. The encryption is asymmetric encryption, such as elliptic curve or RSA. Asymmetric encryption is a technique that uses two encryption keys: a public key and a private key. The public key is shared unrestrictedly, while the private key is known only to the meter that generated it. The public key associated with the private key of the meter is known in particular to the SI and more particularly to the key management system KMS. Thus, the meter uses its private key to encrypt the tag HASH to obtain the signature HASH', and the recipient (in this case the meter data management system MDMS) can decrypt the signature HASH' with the public key of the meter. The meter data management system MDMS will retrieve it from the KMS, thereby authenticating the meter that sent the frame.

[0088] The use of elliptic curve encryption advantageously makes it possible to limit the size of the signature HASH'. In fact, asymmetric encryption of the RSA type uses larger-sized encryption keys than elliptic curve asymmetric encryption using encryption keys with a size of 256 to 384 bits, such as 2048 to 8192 bits. The size of HASH' depends on the size of HASH on the one hand and on the size of the meter's private key on the other hand. Thus, when both the tag HASH and the meter's private key are 256 bits, the size of the signature HASH' is 512 bits. When both HASH and the meter's private key are 384 bits, the size of HASH' is 768 bits.

[0089] In step S306, the meter sends a frame T including a header and payload (in English, "payload" means the effective load) to the meter data management system MDMS. Figure 5 Such a frame T is shown. The frame is generated according to a communication protocol such as G3-PLC, PRIME, 2G, 3G, 4G or 5G. The header of the frame particularly includes the identifier Id of the meter that sends the frame cpt and other data, such as check data and synchronization data required for demodulating the data frame, depending on the communication protocol used for sending. The payload includes the signature HASH′ and the consumption data Idx of the meter. The frame is sent to the meter data management system MDMS via a data concentrator as shown, for example, according to the selected communication protocol Figure 1 shown.

[0090] The method ends in step S308.

[0091] A particularly advantageous aspect of the method is that only the consumption data is sent in the payload of the frame. In fact, the CRC and MID certificate number of the metering software are not sent. Thus, the network load is reduced.

[0092] Figure 6 A receiving method for a meter data management system to receive consumption data from a meter according to a specific embodiment is shown. The method is implemented in the information system SI, and more particularly by the meter data management system MDMS of the information system SI. The meter data management system MDMS particularly includes a non-volatile memory in which the serial numbers of the meters registered with the information system SI are stored. For each meter, and thus for each serial number, the meter data management system MDMS also stores the MID certificate number and the CRC of the metering software.

[0093] The method starts in step S400.

[0094] In step S402, the meter data management system MDMS receives the frame T, which includes the signature HASH′ and the consumption data from the meter in its payload and includes the identifier Id of the meter in its header cpt .

[0095] In step S404, the meter data management system MDMS uses the public key associated with the meter identified by the identifier Id in the header of the frame cpt to decrypt the signature. In fact, the MDMS finds the serial number of the meter based on the identifier Id of the meter present in the header of the frame cpt and then finds the associated public key. The MDMS notifies the KMS that it wishes to retrieve the public key associated with the serial number and / or identifier Id cptThe public key associated with the identified meter. For this, the MDMS sends a request to the KMS, and the KMS sends back to it the public key associated with the meter. This public key is used to decrypt the received signed HASH′.

[0096] In step S406, the MDMS generates a tag HASH″ based on a triple associated with the meter identifier Id cpt The triple includes a serial number, the CRC of the metering software, and the MID certificate number associated with the meter identified by Id cpt These data are stored in the non-volatile memory of the MDMS. In other words, the MDMS uses the data that the MDMS has for the meter identified by Id cpt That is, the serial number, the CRC of the metering software, and the MID certificate number, to perform the same operations as those performed by the meter in step S302. In particular, the MDMS uses the same hashing function in step S406 as that used in step S302.

[0097] In step S408, the MDMS compares the tag HASH″ generated in step S406 with the tag obtained from the signed HASH′ decrypted in step S404. If the two are equal, the method proceeds to step S412. In fact, if the two are equal, the MDMS determines that the consumption data present in the payload of frame T indeed comes from the correct meter, that is, the meter that should have sent the consumption data, and also determines that the data consumption was obtained through the correct version of the metering software. If the two are not equal, the method proceeds to step S410.

[0098] In step S410, the MDMS sends an alarm signal to the information system SI 110 to indicate that there is a problem with the received consumption data, either because it does not come from the meter it should come from, or because the metering software used to obtain the consumption data is incorrect, such as the wrong version of the metering software.

[0099] The method ends in step S412.

[0100] Reference Figure 4 and Figure 6 The described method runs when new metering software is downloaded to the meter. When new metering software is downloaded to the meter, the private key and the public key are advantageously retained. As a variant, the keys are updated. In the latter case, in order to provide the SI with the new public key, the new public key is signed with the new private key and the whole is signed again with the old private key to prove that the new public key indeed comes from the correct meter, and the new public key is then sent to the KMS in plain text.

[0101] Again referring to Figure 1 , consider the implementation of meter 140a with referenceFigure 4 The described method. Thus, the meter 140a generates a frame T that includes in its payload the power consumption data and the signature obtained by implementing steps S302 and S304. The meter 140a then sends its frame to the data concentrator DC 120a via the power line, for example, through the power network. The generated frame is, for example, according to the G3-PLC or PRIME communication protocol.

[0102] The data concentrator DC 120a receives the frame T and sends it again to the information system SI 110 on the communication network 101NET (e.g., a cellular network of the GPRS type), more precisely, to the HES of the information system SI 110. For this purpose, the data included in the received frame T is recovered to be unpacked and then repacked in a frame compatible with the communication network 101NET.

[0103] The HES of the SI, which is the network header, receives the frame T and sends it to the MDMS.

[0104] The MDMS retrieves from the KMS the public key required to verify the signature included in the payload of the verification frame "A".

[0105] Figure 7 Shows a method for sending consumption data (denoted as Idx) by a meter according to a particular embodiment. The consumption data is, for example, the reading of an electricity meter, a water meter, etc.

[0106] The method starts at step S700.

[0107] In step S702, the meter generates a tag, denoted as HASH, based on a quadruple that includes the serial number of the meter, a cyclic redundancy code or CRC (abbreviation of the English "Cyclic Redundancy Code") calculated based on the metering software used by the meter, the MID certificate number assigned to the meter, and the consumption data Idx. The certificate certifies that the meter is authorized for consumption settlement operations. For this purpose, a hash function is used, for example, a function of the SHA-2 family. A particular function is called the hash function H(.), in English "hash function": it calculates a digital tag based on the data provided as input, and the digital tag is used to quickly identify the initial data. In other words, a given quadruple corresponds to a unique tag, which is the result of the hash function. Thus, for two different quadruples T1 and T2, the meter generates two tags S1 = H(T1) and S2 = H(T2), where S1 and S2 are different.

[0108] In one embodiment, the function H(.) is a function of the SHA-2 family, such as SHA-224, SHA-256, SHA-384 or SHA-512. In the case where the function H(.) is of the SHA-256 type, the resulting tag HASH consists of 256 bits. In the case where the function H is of the SHA-512 type, the resulting tag HASH consists of 512 bits. Other functions can be used, such as SHA-3 function, MD4 function, MD5 function, SHA-1 function, which are well known in the field of cryptography; these examples are obviously not restrictive.

[0109] In an implementation variant, an optional padding step is applied to the quadruple in order to obtain an integer number of bytes before applying the hash function H(.).

[0110] In step S704, the meter encrypts the generated tag with a private key known only to the meter. The encrypted tag is a signature and is denoted as HASH'. This private key is generated in advance by the meter based on its serial number. In a particular embodiment, the private key is generated by applying the "exclusive OR" operator between an N-bit random value specific to the meter and H(serial number), for example N = 256 and H() is the SHA-256 function, to obtain a 256-bit private key. The public key associated with this private key is known in particular to the key management system KMS. The encryption is asymmetric encryption, such as elliptic curve or RSA. Asymmetric encryption is a technique that uses two encryption keys: a public key and a private key. The public key is shared without restriction, while the private key is known only to the meter that generated it. The public key associated with the meter's private key is known in particular to the SI and more particularly to the key management system KMS. Thus, the meter uses its private key to encrypt the tag HASH to obtain the signature HASH', and the recipient (in this case the meter data management system MDMS) can decrypt the signature HASH' with the meter's public key, and the meter data management system MDMS will retrieve it from the KMS, thereby authenticating the meter that sent the frame.

[0111] The use of elliptic curve encryption advantageously makes it possible to limit the size of the signature HASH'. In fact, asymmetric encryption of the RSA type uses larger-sized encryption keys than elliptic curve asymmetric encryption using encryption keys of size 256 to 384 bits, such as 2048 to 8192 bits. The size of HASH' depends on the size of HASH on the one hand and on the size of the meter's private key on the other hand. Thus, when both the tag HASH and the meter's private key are 256 bits, the size of the signature HASH' is 512 bits. When both HASH and the meter's private key are 384 bits, the size of HASH' is 768 bits.

[0112] In step S706, the meter sends frame T including a header and payload (English for "payload") to the meter data management system MDMS. Figure 5 Such a frame T is shown. The frame is generated according to a communication protocol such as G3-PLC, PRIME, 2G, 3G, 4G or 5G. The header of the frame particularly includes the identifier Id of the meter that sends the frame cpt and other data, such as check data and synchronization data required for demodulating the data frame, depending on the communication protocol used for sending. The payload includes the signature HASH' and the consumption data Idx of the meter. The frame is sent to the meter data management system MDMS via a data concentrator as shown, for example, according to the selected communication protocol Figure 1 as shown.

[0113] The method ends in step S708. Thus, in this embodiment, the consumption data is used to generate the signature HASH' in addition to being sent.

[0114] A particularly advantageous aspect of the method is that only the consumption data is sent in the payload of the frame. In fact, the CRC and MID certificate number of the metering software are not sent. Thus, the network load is reduced.

[0115] Figure 8 A receiving method by which a meter data management system receives consumption data from a meter according to a specific embodiment is shown. The method is implemented in the information system SI, more particularly by the meter data management system MDMS of the information system SI. The meter data management system MDMS particularly includes a non-volatile memory in which the serial numbers of the meters registered with the information system SI are stored. For each meter, and thus for each serial number, the meter data management system MDMS also stores the MID certificate number and the CRC of the metering software.

[0116] The method starts in step S800.

[0117] In step S802, the meter data management system MDMS receives frame T, which includes the signature HASH' and consumption data from the meter in its payload and the identifier Id of the meter in its header cpt .

[0118] In step S804, the meter data management system MDMS uses the public key associated with the meter identified by the identifier Id in the header of the frame cpt to decrypt the signature. In fact, the MDMS is based on the identifier Id of the meter present in the header of the frame cptFind the serial number of the meter and then find the associated public key. The MDMS notifies the KMS that it wishes to retrieve the public key associated with the meter identified by the serial number and / or identifier Id cpt The MDMS sends a request to the KMS for this purpose, and the KMS sends back to it the public key associated with the meter. This public key is used to decrypt the received signed HASH'.

[0119] In step S806, the MDMS generates a tag HASH″ based on the quadruple associated with the meter identifier Id cpt The quadruple includes the serial number of the meter, the CRC of the metering software, the MID certificate number associated with the meter identified by Id cpt and the consumption data of the meter from the frame received by the MDMS. These data are stored in the non-volatile memory of the MDMS. In other words, the MDMS uses the data that the MDMS has for the meter identified by Id cpt i.e., the serial number, the CRC of the metering software, the consumption data Idx, and the MID certificate number, to perform the same operations as the meter did in step S702. In particular, the MDMS uses the same hashing function in step S806 as it used in step S702.

[0120] In step S808, the MDMS compares the tag HASH″ generated in step S806 with the tag obtained from the signed HASH′ decrypted in step S804. If the two are equal, the method proceeds to step S812. In fact, if the two are equal, the MDMS determines that the consumption data present in the payload of frame T indeed comes from the certified software of the correct meter (i.e., the meter that should have sent the consumption data), and also determines that the data consumption was obtained through the correct version of the metering software. If the two are not equal, the method proceeds to step S810.

[0121] In step S810, the MDMS sends an alert signal to the information system SI 110 to indicate that there is a problem with the received consumption data, either because it does not come from the meter it should come from, or because the metering software used to obtain the consumption data is incorrect, such as the metering software version is wrong.

[0122] The method ends in step S812.

[0123] Reference Figure 7 and Figure 8The described method runs in the case where new metering software is downloaded to the meter. When new metering software is downloaded to the meter, the private key and the public key are advantageously retained. As a variant, the keys are updated. In the latter case, in order to provide the new public key to the SI, the new public key is signed with the new private key and the whole is signed again with the old private key to prove that the new public key really comes from the right meter, and the new public key is then sent in clear text to the KMS.

[0124] Referring again to Figure 1 , consider the implementation of the method described with reference to meter 140a Figure 7 The meter 140a generates a frame T that includes in its payload the power consumption data and the signature obtained by implementing steps S702 and S704. The meter 140a then sends its frame to the data concentrator DC 120a, for example, via the power line through the power network. The generated frame is, for example, according to the G3-PLC or PRIME communication protocol.

[0125] The data concentrator DC 120a receives the frame T and sends it again to the information system SI 110 on the communication network 101NET (for example, a cellular network of the GPRS type), more precisely, to the HES of the information system SI 110. For this purpose, the data contained in the received frame T is recovered to be unpacked and then repacked in a frame compatible with the communication network 101NET.

[0126] The HES of the SI, as the network header, receives the frame T and sends it to the MDMS.

[0127] The MDMS retrieves from the KMS the public key required to verify the signature contained in the payload of the verification frame "A".

Claims

1. A method for a meter to send consumption data to a meter data management system, comprising the following steps implemented by the meter: - Obtain (S301) consumption data, which is obtained by metering software; - Generate (S302) a tag based on a quadruple, the quadruple including the obtained consumption data and a triple, the triple including the serial number of the meter, a cyclic redundancy code calculated based on the metering software, and a certificate number proving that the meter is authorized for consumption settlement; - Encrypt (S304) the tag with a private key known only to the meter, and the encrypted tag then becomes a signature; And - Send (S306) a frame to the system for managing the consumption data, the frame including the identifier of the meter, the obtained consumption data, and the signature.

2. The sending method according to claim 1, wherein, generating the tag includes applying a hash function to the quadruple.

3. The sending method according to claim 1, wherein, the hash function belongs to a group of hash functions including the following: - SHA-224 of the SHA-3 family; - SHA-256 of the SHA-3 family; - SHA-384 of the SHA-3 family; - SHA-512 of the SHA-3 family; - SHA-224 of the SHA-2 family; - SHA-256 of the SHA-2 family; - SHA-384 of the SHA-2 family; - SHA-512 of the SHA-2 family; - MD-4; - MD-5; and - SHA-1.

4. The sending method according to any one of claims 1 to 3, wherein, encrypting the tag with a private key known only to the meter includes applying asymmetric elliptic curve encryption.

5. The sending method according to any one of claims 1 to 4, wherein, the consumption data is consumption data of electricity, gas, gasoline, heat energy or water.

6. A receiving method for a system for managing consumption data to receive the consumption data, the system for managing the consumption data stores triples in a memory for each meter in a group of meters, the triples including the serial number of the meter, a cyclic redundancy code of the metering software, and a relevant certificate number proving that the meter is authorized for consumption settlement, the method including the following steps implemented by the system for managing the consumption data: - Receive (S402) a frame including the identifier of the meter, consumption data, and a signature; - Decrypt (S404) the signature with the public key associated with the meter identified by the identifier; - Generate (S406) a tag based on a quadruple, the quadruple including the received consumption data and the triple associated with the meter identified by the identifier in the memory; and - Compare (S408) the decrypted signature and the generated tag, and send an alarm signal if the two are not equal.

7. A method for a meter to send consumption data to a system for managing the consumption data, where the system for managing the consumption data stores triples in a memory for each meter in a group of meters, the triples including the serial number of the meter, the cyclic redundancy code of the metering software, and the relevant certificate number proving that the meter is authorized for consumption settlement. The method includes the following steps implemented by the meter: - Obtain (S301) the consumption data, which is obtained by the metering software; - Generate (S302) a tag based on a quadruple, the quadruple including the obtained consumption data and the triple, the triple including the serial number of the meter, the cyclic redundancy code calculated based on the metering software, and the certificate number proving that the meter is authorized for consumption settlement; - Encrypt (S304) the tag with a private key known only to the meter, and the encrypted tag then becomes a signature; And - Send (S306) a frame to the system for managing the consumption data, the frame including the identifier of the meter, the obtained consumption data, and the signature; and The method further includes the following steps implemented by the system for managing the consumption data: - Receive (S402) the frame; - Decrypt (S404) the signature with the public key associated with the meter identified by the identifier; - Generate (S406) a tag based on a quadruple, the quadruple including the received consumption data and the triple associated with the meter identified by the identifier in the memory; And - Compare (S408) the decrypted signature and the generated tag, and send an alarm signal if they are not equal.

8. A meter configured to send consumption data to a system for managing the consumption data, the meter comprises: - A component for obtaining consumption data, which is obtained by the metering software; - A component for generating a tag based on a quadruple, the quadruple including the obtained consumption data and a triple, the triple including the serial number of the meter, the cyclic redundancy code calculated based on the metering software, and the certificate number proving that the meter is authorized for consumption settlement; - A component for encrypting the tag with a private key known only to the meter, and the encrypted tag then becomes a signature; And - A component for sending a frame to the system for managing the consumption data, the frame including the identifier of the meter, the obtained consumption data, and the signature.

9. A meter data management system that stores triples in a memory for each meter in a group of meters, the triples including the serial number of the meter, the cyclic redundancy code of the metering software, and the relevant certificate number proving that the meter is authorized for consumption settlement. The meter data management system comprises: - A component for receiving a frame including the identifier of a meter, consumption data, and a signature; - A component for decrypting the signature with the public key associated with the meter identified by the identifier; - A component for generating a tag based on a quadruple, the quadruple including the received consumption data and the triple associated with the meter identified by the identifier in the memory; And - A component for comparing the decrypted signature and the generated tag and sending an alarm signal if they are not equal.

10. An automated management system configured to remotely collect consumption data, the automated management system including at least one meter according to claim 8 and a meter data management system according to claim 9.

11. A computer program product including instructions for implementing the sending method according to any one of claims 1 to 5 or the receiving method according to claim 6 when the program is executed by a processor.

12. A storage medium storing a computer program including instructions for implementing the sending method according to any one of claims 1 to 5 or the receiving method according to claim 6 when the program is executed by a processor.

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