Robust storage

Abstract

Robust Storage This description relates to a method comprising: - transmitting, via at least one peripheral circuit of a storage system for a motor vehicle, one or more data items to be stored, to at least two circuits of the vehicle; - searching for a proof-of-work; - when one of the at least two circuits has found a potential proof-of-work, transmitting the potential proof-of-work to each of the other circuits; - verifying the potential proof-of-work; and - if the verification confirms that the potential proof-of-work corresponds to the proof-of-work sought, storing, in each of the circuits, one or more data items in a current block of a blockchain, the data item(s) being stored in association with an identifier value from the previous block, the proof-of-work, and an identifier value from the current block. Figure for the abstract: Fig. 3

Description

Title of the invention: Robust storage technical field

[0001] This description relates generally to the storage of parameters describing events and / or states of a motor vehicle. Previous technique

[0002] During the operation of a motor vehicle, data describing states, such as, for example, speed, engine speed, tire pressure, braking times, etc., are recorded and stored periodically in a non-volatile memory of the vehicle.

[0003] Storing this data makes it possible to trace the history of the vehicle, for example following an accident.

[0004] However, in the event that the non-volatile memory in which this data is stored is damaged, for example during a shock, the data may be lost.

[0005] There is a need to improve the way this data is stored in order to reduce the risk of losing access to this data in the event of an accident damaging the vehicle. Furthermore, it is desirable that the accessible data be intact. Summary of the invention

[0006] One embodiment provides a method comprising: - the transmission, by at least one peripheral circuit of a data storage system for a motor vehicle, of one or more data to be stored, to at least two circuits of the motor vehicle; - the search, by each of the at least two circuits, for proof of work; - when a first of the at least two circuits has found a potential proof of work, the transmission, by said first circuit, of the potential proof of work found to each of the other circuits among the at least two circuits; - the verification, by each of the other circuits, of the potential proof of work; and - if the verification confirms that the potential proof of work corresponds to the proof of work sought, the storage, in each of the circuits, of one or more data in a current block of a blockchain, the data being stored in association with an identification value of the directly preceding block in the blockchain, the proof of work and an identification value of the current block, the identification value of the current block being calculated on the basis of the identification value of the directly preceding block, one or more data and the proof of work.

[0007] According to one embodiment, the above process further includes, before storage in each of the at least two circuits, the calculation of a signature value on the basis of the data(s), the identification value of the current block being further calculated on the basis of the signature value.

[0008] According to one embodiment, the identification value of the current block is a hash value.

[0009] According to one embodiment, the search for proof of work, by each of the at least two circuits, comprises: a) the generation, by a number generator of said circuit, of a candidate value; b) the provision of the candidate value to a processor of said circuit; c) checking whether the candidate value corresponds to a target challenge value for a given response value; and d) if the candidate value does not match, repeat a), b) and c) one or more times.

[0010] According to one embodiment, the candidate value corresponding to the target challenge value is the proof of work.

[0011] According to one embodiment, the data corresponds to recordings of parameters of the motor vehicle when its engine is running.

[0012] According to one embodiment, the above process further includes other transmissions, by at least one peripheral circuit, of one or more other data to be stored, to at least two circuits, the other transmissions taking place at regular time intervals.

[0013] One embodiment provides a data storage system for a motor vehicle, the system comprising: - at least one peripheral circuit configured to transmit one or more data items to be stored to at least two circuits; - at least two circuits configured to: search for proof of work; As soon as a potential proof-of-work has been found by at least one of the two circuits, said first circuit is further configured to: transmit the potential proof-of-work found to each of the other circuits among the at least two circuits, said other circuits being further configured to verify the potential proof-of-work; and If the potential proof-of-work matches the required proof-of-work, the at least two circuits are further configured to: to store one or more data points in a block of a blockchain, the data point(s) being stored in association with an identification value of the directly preceding block in the blockchain, the proof of work and a value current block identification, the current block identification value being calculated based on the identification value of the directly preceding block, one or more data points, and proof of work.

[0014] One embodiment provides for a motor vehicle comprising the above system, in which the at least two circuits are distributed in a network within the motor vehicle, each circuit being connected to each of the other circuits by a communication link.

[0015] According to one embodiment, the communication link between the circuits uses a wired communication protocol, for example of the Ethernet type or of the area control network type, CAN.

[0016] According to one embodiment, the network formed by the circuits uses a wireless communication protocol.

[0017] According to one embodiment, at least 5, and for example at least 10, circuits form the network.

[0018] According to one embodiment, at least one peripheral circuit is configured to record one or more vehicle parameters, one or more parameters corresponding to the transmitted data.

[0019] One embodiment provides a secure circuit comprising: - a number generator configured to generate candidate values; - a processor configured to check if each generated candidate value corresponds to a target challenge value; and - a non-volatile memory comprising a blockchain, the circuit further being configured to, when a candidate value matches the target challenge value, transmit said candidate value as a proof of work to other circuits, or to receive a proof of work, transmitted by another circuit, the processor then further being configured to check whether the proof of work matches the target challenge value, the non-volatile memory being configured to store, in a current block of the blockchain, the data in association with an identification value of the block directly preceding the current block, an identification value of the current block and the proof of work, the processor further being configured to generate the value of the current block on the basis of the identification value of the block directly preceding, the data and the proof of work. Brief description of the drawings

[0020] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0021] [Fig.1] is a block diagram representing a data storage system, according to an embodiment of the present description;

[0022] [Fig.2] is a block diagram representing a network of secure circuits;

[0023] Figure 3 illustrates a data storage structure in secure circuits, according to an embodiment of this description; and

[0024] [Fig.4] is a flowchart illustrating steps in a data storage process, according to an embodiment of the present description. Description of the implementation methods

[0025] The same elements have been designated by the same reference numerals in the different figures. In particular, structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0026] For the sake of clarity, only the steps and elements necessary for understanding the described embodiments have been shown and are detailed. In particular, the hashing and signature calculation operations are not described in detail. Similarly, the proof-of-work validation protocols are not described in detail and are known to those skilled in the art.

[0027] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") together, this means that these two elements can be connected or linked through one or more other elements.

[0028] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures.

[0029] Unless otherwise specified, the expressions "approximately", "roughly", and "in the order of" mean within 10%, preferably within 5%.

[0030] Figure 1 is a block diagram representing an electronic system 100, according to an embodiment of the present description. In one embodiment, the system 100 is a data storage system for a motor vehicle.

[0031] The system 100 includes, for example, a router 102 (ROUTER) adapted to receive and transmit data 104 (DATA). In one example, the router 102 is an internet communication module, such as a module with access to a fifth-generation (5G) mobile network, or a module with internet access via a Wi-Fi wireless communication protocol. The router 102 is therefore adapted to receive and transmit data within system 100, but also with one or more other electronic systems external to system 100.

[0032] The system 100 is, for example, adapted to implement a multitude of functionalities that are grouped into several operating domains. The system 100 comprises, for example, N operating domains 106-1 (DCU1), 106-2 (DCU2), ... and 106-N (DCUN), N being an integer greater than or equal to two. Each operating domain 106-i, i being an integer ranging from 1 to N, comprises at least one circuit 108-i and one or more, generally several, electronic devices 110 (ECUs), each adapted to implement one or more functionalities. In some embodiments, the circuits 108-i are secure circuits or secure elements, including secure storage means.

[0033] A first area of ​​operation may relate to the engine and include electronic devices managing, for example, fuel injection, engine operating modes, sensors for monitoring engine function and / or wear, etc. A second area of ​​operation may relate to safety within the vehicle and include electronic devices managing, for example, tire pressure, brakes, emergency calls, etc. A third area of ​​operation may relate to the vehicle's interior and include electronic devices managing, for example, air conditioning, heating, lighting, etc. A fourth area of ​​operation may relate to the vehicle's multimedia content and include electronic devices managing, for example, a radio or car stereo, a sound system, one or more screens, etc.

[0034] In one example, one or more of the operating domains are configured to record historical data, such as, for example, vehicle speed, engine running time, brake wear, tire pressure, the vehicle's GPS (Global Positioning System) location, engine temperature, engine speed, and many other examples. This historical data is, for example, provided to router 102. In one embodiment, router 102 is configured to control the storage of historical data in each of the secure circuits. By way of example, router 102 is configured to control the storage of historical data acquired, for example, by the operating domains and / or other peripheral circuits of the motor vehicle, at regular time intervals, for example, every second, every minute, or every hour.Router 102 is, for example, further configured to control the storage of historical data acquired each time the vehicle's engine is switched off. In this case, system 100 remains powered for a certain period of time, for example about ten seconds. following the engine shutdown, in order to be able to proceed with the storage of historical data in the secure 108-i circuits.

[0035] Figure 2 is a block diagram of the secure circuits 108-i (ESE) distributed in a network 200 within a data storage system, for example, within a motor vehicle. Although the network 200 shown in Figure 2 comprises the secure circuits 108-1 to 108-5, it is entirely possible for the network 200 to consist of a larger, or smaller, number of secure circuits. For example, the network 200 comprises ten secure circuits. For example, each secure circuit 108-i belongs to a different operating domain of the vehicle. In another example, two secure circuits among the secure circuits of the network 200 are located in the same operating domain of the vehicle.

[0036] By way of example, each 108-i secure circuit is connected to each of the other 108-i secure circuits via a 201 link. For clarity, [Fig. 2] illustrates only some 201 links between the 108-i secure circuits. For example, the 201 links are wired and implement a wired communication protocol, such as Ethernet. In another example, the 201 links are wireless, implementing a communication protocol such as WiFi or 5G.

[0037] Each secure circuit 108-i includes one or more storage means, such as a register or a non-volatile memory 202, for securely storing data. In particular, each secure circuit 108-i is resistant to side-channel attacks. Mechanisms for protecting against such attacks are well known to those skilled in the art and will not be detailed here. In one embodiment, each non-volatile memory 202 is configured to store a historical data sequence in a data structure forming a blockchain.

[0038] Each secure circuit 108-i includes, for example, a processor 204 (CPU) and a number generator 206 (RNG). When the router 102 commands the storage of the history data 104, each number generator 206 is configured, for example, to generate a value and transmit it to the processor 204 of the secure circuit. The processor 204 is then configured to check whether the generated value solves a mathematical problem predefined upstream.

[0039] By way of example, the mathematical problem to be solved consists of finding a challenge value for a given answer value. For example, a main processor, which may be another processor of the system 100 (not shown) connected to the network 200, or one of the processors 204 of the secure circuits 108-i, generates a target hash value, for example randomly, and transmits it to each of the secure circuits 118-i. Each number generator 206 then generates a candidate value which it transmits to the corresponding 204 processor. Each 204 processor is then configured to apply a hash function, such as SHA-256, SHA-512, etc., to the candidate value and to verify whether the resulting hash value matches the target hash value transmitted by the main processor. As soon as a 108-i secure circuit detects that a generated candidate value matches a value that, after hashing, results in the target hash value, the generated candidate value becomes a potential proof-of-work, and this value is transmitted by the secure circuit in question to each of the other 108-i secure circuits. Each of the other 108-i secure circuits is then configured to verify that the potential working value transmitted by the secure circuit in question does indeed result, after application of the hash function, in the target hash value.The value generated then constitutes proof of work.

[0040] Generally, as an alternative to a hash function, other mathematical problems can be provided to the 108-i secure circuits. The principle is that each 108-i secure circuit tests, one by one, the values ​​generated by its 206 number generator to verify whether they correspond to a challenge value for a given answer value, for example, provided by the main processor, and for a predefined "challenge-answer" type mathematical problem. The mathematical problem is such that the challenge value is difficult to find but easily verifiable. Thus, the relationship between the challenge value and the answer value can be a hash function or another cryptographic operation. The operation linking the challenge value to the answer value is a bijective operation; for example, each answer value is associated with a unique challenge value.

[0041] According to one embodiment, the storage of history data in each of the secure circuits 108-i is conditional upon the search for proof of work.

[0042] Figure [Fig. 3] illustrates an example of a data storage structure 300 in the secure circuits 108-i of Figures [1] and 2, according to an embodiment of the present description.

[0043] According to one embodiment, each secure circuit 108-i comprises the storage structure 300. In some embodiments, the structure 300 and the data contained therein are exactly identical from one secure circuit 108-i to another.

[0044] According to one embodiment, the structure 300 takes the form of a blockchain. Each time router 102 commands the storage of historical data, a new block is added to the existing blocks. The blockchain thus comprises a history of parameters and / or states describing the operation of the motor vehicle since, for example, its registration.

[0045] Fig. 3 illustrates in particular three successive blocks 302 (BLOCK Nl), 304 (BLOCK N) and 306 (BLOCK N+l) of the 300 block chain.

[0046] Block 302 includes, for example, an identification value 308 (N-2 HASH) from the directly preceding block in the 300 block chain. As an example, the identification value 308 is a value obtained following the application of a hashing operation on the content of the directly preceding block.

[0047] Block 302 further includes historical data 310 (DATA Nl) associated with the Nth storage command, where N is an integer greater than or equal to 1. Block 302 further includes a signature value 312 (SIGNATURE Nl). For example, the signature value 312 is a signature obtained from the data 310.

[0048] According to one embodiment, block 302 further includes the value of a proof-of-work 314 (POW Nl). The proof-of-work 314 is, for example, a value generated by one of the secure circuits 108-i and solving a mathematical problem. This value is verified by the other secure circuits 108-i, and if the verification is successful, the value is stored as a proof-of-work in block 302. The search for the proof-of-work 314 is performed following the data storage command 310. The construction of block 302 is carried out once the proof-of-work 314 has been found and verified by all the secure circuits 108-i.

[0049] Block 302 further includes an identification value 316 (HASH Nl) of block 302. The identification value 316 is, for example, calculated by each processor 204 by applying a hash operation to the identification value 308, the data 310, the signature 312 and the proof of work 314. As an example, the hash operation is applied to a concatenation of the values ​​and data 308, 310, 312 and 314.

[0050] Block 304 is then added to the chain of blocks 300, directly following block 302. As an example, block 304 is added following the command to store new historical data 318 (DATA N) acquired, for example, directly following historical data 310.

[0051] The identification value 316 of block 302 is stored in block 304. Storing the identification value 316 in block 304 allows blocks 302 and 304 to be linked together. It is then impossible for a third party to add another block between blocks 302 and 304.

[0052] Block 304 further includes the history data 318 and a signature value 320 (SIGNATURE N). The signature value 320 is, for example, a signature of the history data 318. Just like block 302, block 304 includes a proof-of-work 322 (POW 322).

[0053] Proof-of-work 322 is retrieved following data storage command 318. In particular, the value of proof-of-work 322 differs from the value of proof-of-work 314 because it solves a different mathematical problem than that used for proof-of-work search 314. As an example, the main processor generates a new hash value at each history data storage command and provides it as the response value to each of the secure circuits 108-i. The proof-of-work for each block in the blockchain 300 then corresponds to the resulting challenge value divided by the provided response value.

[0054] Block 304 further includes an identification value 324 (HASH N). As an example, the identification value 324 is obtained by applying a hashing operation to the values ​​and data 316, 318, 320 and 322.

[0055] The identification value 324 will then be stored in block 306, directly following block 304 in order to directly link the two blocks. The structure of block 306 is identical to that of blocks 302 and 304. In other words, block 306 includes, in addition to the identification value 324, historical data 326 (DATA N+1) acquired following data 318, a signature 328 (SIGNATURE N+1) and a proof of work 328 (POW N+1). Proof-of-work 330 is sought based on a different response value than those used for blocks 302 and 304. Block 306 will also include an identification value 332 (N+1 HASH) calculated based on the values ​​and data 324, 326, 328, and 330. The identification value 332 will then also be stored in the block directly following block 306 in order to link them directly.

[0056] By way of example, for each of the blocks in the 300 blockchain, and in particular for blocks 302, 304 and 306, the identification values ​​308, 316 and 324 of the directly preceding block are stored at the beginning of the block, followed respectively and in order, by the history data 310, 318 and 326, the signature 312, 320 or 328, the proof of work 314, 322 or 330 and then the identification value 316, 324 or 332. By way of example, each block in the 300 blockchain begins with the identification value of the directly preceding block and ends with its own identification value.

[0057] Fig. 4 is a flowchart illustrating steps in a data storage process, according to an embodiment of the present description.

[0058] In a 401 (SAVING REQUEST) step, a request to store historical data is initiated. For example, the request is made by router 102 or by the main processor, and is transmitted to the secure circuits 108-i.

[0059] By way of example, the process continues in a step 402 (SIGNATURE COMPUTATION) in which a signature of the historical data is calculated. By way of example, the signature is calculated by each processor 204 of the secure circuits 108-i.

[0060] In a step 403 (POW BY ALL ESE), the main processor provides, for example, the same mathematical problem to each of the secure circuits 108-i. As an example, the main processor provides a value, for example generated randomly, to the 108-i secure circuits. As an example, the value corresponds to a hash value, or more generally to the result of a bijective cryptographic operation on a challenge value. Solving the mathematical problem involves each of the 108-i secure circuits independently finding the challenge value, which, when the hash operation, or more generally the bijective cryptographic operation, is applied to it, results in the value generated by the main processor.

[0061] The search for the challenge value includes the generation, by each of the number generators 206 of each of the safety circuits 108-i, of a candidate value and the verification, for example by the processors 206, of whether the generated candidate value corresponds to the challenge value for the response value provided by the main processor. The safety circuits 108-i therefore search, in parallel and independently of each other, for the value corresponding to the challenge for the provided response value.

[0062] During the execution of step 403, the 108-i safety circuits are in competition. As long as the value is not found, the safety circuits are configured to regenerate new values ​​and test them, each on its own.

[0063] When one of the 108-i safety circuits finds the correct challenge value, the value is transmitted, in a step 404 (VERIFICATION), to the other 108-i safety circuits. The other 108-i circuits are then configured to verify, for example via the 204 processors, whether the value is indeed the correct challenge value. If the challenge value provided is ultimately incorrect, all the 108-i safety circuits are configured to resume the search.

[0064] If, following the verification performed by each of the 108-i secure circuits, it is determined that the provided value is indeed the challenge value corresponding to the response value provided by the main processor, the search terminates. The verified challenge value is then stored in memory in each of the 108-i secure circuits and constitutes a proof of work.

[0065] In a 405 step (HASH), a hashing operation is, for example, applied by each of the processors 206 to the identification value of the last block of the block chain 300 stored, for example, in each of the volatile memories 204. The hashing operation is further applied to the history data, for example provided by the router 102, to the signature value calculated during the execution of step 402 and to the proof of work, verified during the execution of step 404. The result of the hashing operation then constitutes an identifier of the block of the block chain in which the history data will be stored.

[0066] Following the calculation of the identification value, a new block is added, for example by each processor 204, to the chain of blocks stored, for example, in the non-volatile memory 202. Each processor 204 is further configured to store, in this new block and in a step 406 (STORAGE BY ALL ESE), the identification value of the directly preceding block, the history data, the signature value, the proof and work and the identification value calculated in step 405. An example of the structure of the block chain stored in memory 202 and of the structure of each block is described in relation to [Fig.3].

[0067] Following the completion of step 406, each 108-i secure circuit comprises a blockchain, stored in its non-volatile memory 202. For each 108-i secure circuit, the blockchain is identical to the other blockchains stored in the other 108-i secure circuits. Thus, each 108-i secure circuit comprises a historical data sequence, each element of the sequence being stored, in a block of the chain, in association with other values, such as identification values, the signature value, and the proof-of-work.

[0068] Following step 405, the process resumes in a new embodiment of step 401 when further historical data needs to be stored. For example, when the motor vehicle is running, the process repeats at regular time intervals. For example, turning off the engine also triggers step 401. In each embodiment of the sequence of steps 401 to 406, the answer value provided by the main processor for solving the mathematical problem differs. Furthermore, following each embodiment of the sequence of steps 401 to 406, a new block is added to the existing blocks in each block chain.

[0069] One advantage of the described embodiments is that a history of the vehicle's operation is stored simultaneously in several secure circuits distributed throughout the vehicle. Thus, if one circuit is damaged, for example following an impact, the history can still be retrieved from the other secure circuits.

[0070] Another advantage of the described embodiments, and more specifically an advantage arising from the historical data storage structure, is that the blockchain is immutable, and in particular cannot be modified by a third party. Indeed, due to the use of identification values, it is not possible to insert a block between two existing blocks. Similarly, it is not possible to add a block without knowing the checksum of the immediately preceding block. It is also not possible to modify the content of a block. In fact, the identification value of a block is calculated from the historical data provided by router 102. Thus, modifying the data would cause a complete loss of consistency in the structure of the blocks and the blockchain.

[0071] Various embodiments and variations have been described. A person skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art.

[0072] Finally, the practical implementation of the described embodiments and variants is within the reach of a person skilled in the art, based on the functional indications given above. In particular, with regard to the search for proof of work, mathematical problems other than those described can of course be used. Since the principle of proof of work is known to a person skilled in the art, they will be able to adapt and choose a suitable type of mathematical problem.

Claims

Demands

1. A method comprising: - the transmission, by at least one peripheral circuit of a data storage system (100) for a motor vehicle, of one or more data items to be stored, to at least two secure circuits (108-1, 108-2, 108-3, 108-5, 108-N) of the motor vehicle; - the search, by each of the at least two secure circuits, for a work proof (322); - when a first of the at least two secure circuits has found a potential work proof, the transmission, by said first secure circuit, of the potential work proof found to each of the other secure circuits among the at least two secure circuits; - the verification, by each of the other secure circuits, of the potential work proof;and - if the verification confirms that the potential proof of work corresponds to the proof of work sought, the storage, in each of the secure circuits, of one or more data in a current block (304) of a blockchain (300), the data being stored in association with an identification value (316) of the directly preceding block in the blockchain, the proof of work (322) and an identification value of the current block (324), the identification value of the current block being calculated on the basis of the identification value of the directly preceding block, one or more data and the proof of work.;

2. A method according to claim 1, further comprising, before storage in each of the at least two secure circuits (108-1, 108-2, 108-3, 108-5, 108-N), the calculation of a signature value (320) on the basis of the data(s), the identification value (324) of the current block (304) being further calculated on the basis of the signature value.

3. Method according to claim 1 or 2, wherein the identification value (324) of the current block (304) is a hash value.

4. A method according to any one of claims 1 to 3, wherein the search for proof of work (322), by each of the at least two secure circuits (108-1, 108-2, 108-3, 108-5, 108-N), comprises: a) the generation, by a number generator (206) of said secure circuit, of a candidate value; b) the provision of the candidate value to a processor (204) of said secure circuit; c) the verification of whether the candidate value corresponds to a target challenge value for a given response value; and d) if the candidate value does not correspond, the repetition of a), b) and c) one or more times.

5. Method according to claim 4, wherein the candidate value corresponding to the target challenge value is the proof of work (322).

6. A method according to any one of claims 1 to 5, wherein the data corresponds to parameter recordings of the motor vehicle when its engine is running.

7. A method according to any one of claims 1 to 6, further comprising other transmissions, by at least one peripheral circuit, of one or more other data to be stored, to the at least two secure circuits (108-1, 108-2, 108-3, 108-5, 108-N), the other transmissions taking place at regular time intervals.

8. A data storage system (100) for a motor vehicle, the system comprising: - at least one peripheral circuit configured to transmit one or more data items to be stored to at least two secure circuits (108-1, 108-2, 108-3, 108-5, 108-N); - the at least two secure circuits configured to: search for a proof of work (314, 322, 330); as soon as a potential proof of work has been found by at least one of the first two secure circuits, said first secure circuit is further configured to: transmit the potential proof of work found to each of the other secure circuits among the at least two secure circuits, said other secure circuits being further configured to verify the potential proof of work;and if the potential proof of work does indeed correspond to the proof of work sought, the at least two circuits are further configured to: store one or more data in a block (302, 304, 306) of a chain of blocks (300), the data being stored in association with an identification value (308, 316, 324) of the block; directly preceding in the blockchain, the proof of work and an identification value (316, 324, 332) of the current block, the identification value of the current block being calculated on the basis of the identification value of the directly preceding block, one or more data points and the proof of work.

9. Motor vehicle comprising the system (100) according to claim 8, wherein the at least two secure circuits (108-1, 108-2, 108-3, 108-5, 108-N) are distributed in a network within the motor vehicle, each secure circuit being connected to each of the other secure circuits by a communication link.

10. Motor vehicle according to claim 9, wherein the communication link between the secure circuits (108-1, 108-2, 108-3, 108-5, 108-N) uses a wired communication protocol, for example of the Ethernet type or of the area control network type, CAN.

11. Motor vehicle according to claim 9, wherein the network formed by the secure circuits uses a wireless communication protocol.

12. Motor vehicle according to any one of claims 9 to 11, wherein at least 5, and for example at least 10, secure circuits (108-1, 108-2, 108-3, 108-5, 108-N) form the network.

13. Motor vehicle according to any one of claims 8 to 12, wherein at least one peripheral circuit is configured to record one or more vehicle parameters, one or more parameters corresponding to the transmitted data.

14. A secure circuit (108-1, 108-2, 108-3, 108-5, 108-N) comprising: - a number generator (206) configured to generate candidate values; - a processor (204) configured to verify whether each generated candidate value corresponds to a target challenge value; and - a non-volatile memory (202) comprising a block chain (300), the circuit further being configured to, when a candidate value corresponds to the target challenge value, transmit said candidate value as a proof-of-work (314, 322, 330) to other secure circuits, or to receive a proof-of-work (322) transmitted by another secure circuit, the processor then further being configured to verify whether the proof-of-work corresponds to the target challenge value, the non-volatile memory being configured to store, in a current block (304) of the blockchain, the data(s) associated with an identification value (316) of the block directly preceding the current block, an identification value (324) of the current block, and the proof of work, the processor is further configured to generate the value of the current block based on the identification value of the directly preceding block, the data(s) and the proof of work.

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