Method for authenticating central unit connected to peripheral unit using secure server
By using secure external servers and dynamic encryption keys in the tire pressure monitoring system, the security and confidentiality problems of sensitive operations under Internet links in the prior art are solved, and sensitive operations and data exchange with high security levels are achieved.
Patent Information
- Application Number
- CN202380036535.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-04-27
- Filing Date
- 2023-04-21
- Publication Date
- 2024-12-13
AI Technical Summary
Existing tire pressure monitoring systems are difficult to ensure high security levels and confidentiality of data exchange when performing sensitive operations over Internet links, especially in the face of challenges in avoiding undesirable interventions and data exchange burdens by third parties.
By using a secure external server, using specific identifiers and shared encryption keys for the central and peripheral wheel units, a two-way authentication process is established to generate dynamic temporary encryption keys, ensuring security when performing sensitive operations on peripheral wheel units in an Internet connection. sex.
It realizes sensitive operation of peripheral wheel units under high security levels and high confidentiality, simplifies the server encryption process, avoids the burden of data exchange, and improves the protection capabilities of the system.
Smart Images
Figure CN119137987A_ABST
Abstract
Description
[Technical field]
[0001] The invention relates to a method for authenticating the authority of a central unit to communicate with peripheral wheel units in order to perform sensitive operations on these peripheral units, using a secure server connected via an Internet link, and to a unit and a motor vehicle comprising a device implementing the method. [Background Technology]
[0002] Document FR-A1-3084310 describes in particular a method for communication between a tire pressure monitoring system (TPMS) of a motor vehicle and a smart device of a user of the vehicle, the method comprising a peripheral unit mounted on each wheel of the vehicle, which measures parameters such as inflation pressure and tire temperature, which are transmitted by radio, and in particular using the Bluetooth standard, to a central unit located in the vehicle, which receives the information in order to process it and notify / alert the driver or repairman if a problem is detected.
[0003] In particular, the wheel units periodically transmit information to the central unit using a specific unique identifier allowing identification of the wheel in question. Each wheel unit also possesses a radio receiver which receives signals from the central unit in order to perform diagnostic, configuration or learning operations on that wheel unit.
[0004] The method uses UHF waves (UHF stands for ultra-high frequency) with a frequency of more than one gigahertz, thus allowing new applications such as communication with devices outside the vehicle, in particular the user's smartphone.
[0005] Furthermore, generally speaking, where a system (e.g., these tire pressure monitoring systems) performs radio exchanges between a central unit of a user or client and peripheral units that record data, it may be necessary to use the Internet and cloud computing services to perform sensitive operations on these peripheral units, such as reprogramming these peripheral units.
[0006] Each unit has a specific MAC (MAC stands for Media Access Control) address stored in a physical memory as an identifier. Authentication of the user's central unit by the peripheral unit in order to perform sensitive operations on the peripheral unit (such as reprogramming) is problematic, since it is difficult to simply ensure a high level of security to avoid unwanted intervention by third parties (such as cracking) and confidentiality of the data exchange without burdening the server with a large amount of data exchange.
[0007] The object of the present invention is in particular to avoid these problems of the prior art. [Summary of the invention]
[0008] To this end, the invention proposes a method for authenticating the authority of a central unit of a user to communicate bidirectionally by radio with one or more peripheral units, the one or more peripheral wheel units performing measurements on the tires of the wheels of a motor vehicle, the measurement results being transmitted to the central unit in order to perform sensitive operations on the peripheral units, each central unit and peripheral unit possessing a specific identifier, the method using a secure external server via the Internet which possesses in a database the identifiers of the peripheral wheel units and a symmetric encryption key shared with each peripheral wheel unit, the method notably comprising the following successive steps:
[0009] - in a first step, the central unit makes itself identifiable to each peripheral wheel unit using its identifier and a password, while in parallel it establishes a secure link with the server by authenticating itself so that the server can recognize in its database the identifier of the peripheral wheel unit in question;
[0010] - In a second step, the peripheral wheel unit generates a new random session code and notifies it to the central unit;
[0011] - in a third step, the central unit transmits to the server its identifier, the identifier of the peripheral wheel unit and a session code in order to request the server to prove its authentication in order to obtain management rights for this peripheral wheel unit;
[0012] - in a fourth step, the server performs a first encryption using the shared encryption key identified by the identifier of the peripheral wheel unit and the session code to form a random and shared dynamic temporary first encryption key, and then, in a fifth step, performs a second encryption using the identifier of the central unit and this dynamic temporary first encryption key to obtain encrypted central unit information by means of an authentication certificate;
[0013] - in a sixth step, transmitting the encrypted central unit information to the central unit, which then, in a seventh step, in turn transmits the encrypted central unit information to the peripheral wheel unit;
[0014] - in an eighth step, the peripheral wheel unit performs a first encryption in parallel using its shared encryption key and its session code, which is the same as the first encryption performed by the server in the fourth step to form a temporary second encryption key, and then, in a ninth step, the peripheral wheel unit performs a reverse decryption of the second encryption of the fifth step using the temporary second encryption key and the encrypted information to obtain a decrypted identifier; and finally
[0015] In a tenth step, the peripheral wheel unit compares the decrypted identifier with the identifier of the central unit so that, if the two identifiers match, the central unit is granted authentication.
[0016] An advantage of the authentication method according to the invention is that it allows simplifying the encryption process of the source files stored in the server in order to avoid overloading the server, the encrypted files having to be created only once for all peripheral wheel units.
[0017] The method for authenticating authority according to the present invention may further include one or more of the following features, which may be combined with each other.
[0018] Advantageously, in the next step, the secure server that generates and hosts the dynamic private encryption key uses the dynamic private encryption key to encrypt the software source file to obtain an encrypted file, and then, in the next step, the server uses the dynamic shared first encryption key to encrypt the private encryption key to obtain a new encryption key, and then, in the next step, the server delivers the encrypted file and the new encryption key to the central unit, and in the next step, the central unit in turn delivers the encrypted file and the new encryption key to the peripheral wheel unit.
[0019] In this case, advantageously, in the next step, the peripheral wheel unit uses the new encryption key and the dynamic temporary first encryption key to form a dedicated encryption key that is identical to the encryption key held by the server, and then, in the next step, the peripheral wheel unit uses the dedicated encryption key to decrypt the encrypted file by performing a reverse operation to the encryption operation previously performed by the server in order to deliver the source file.
[0020] Advantageously, the source file is then verified using a checksum and then programmed into the memory of the peripheral wheel unit.
[0021] Advantageously, the secure link with the server uses the HTTPS protocol, which stands for Hypertext Transfer Protocol Secure.
[0022] Advantageously, once the secure link with the server has been established, the server verifies in its database whether the central unit is authorized to communicate with the peripheral wheel unit.
[0023] Advantageously, during a given communication session opened with the peripheral wheel unit, the central unit again sends encrypted information to the peripheral wheel unit as authentication proof without using the server.
[0024] Another subject of the invention is a system comprising a central unit and a peripheral wheel unit performing the measurements, the central unit and the peripheral wheel unit being connected to each other by radio, the system comprising a device for implementing a method comprising any of the aforementioned features.
[0025] The invention also relates to a motor vehicle comprising a central unit and peripheral wheel units performing measurements on the tires of wheels of the vehicle, the motor vehicle comprising a device implementing a method comprising any of the preceding characteristics. [Drawings]
[0026] [ Figure 1 ] is a functional schematic diagram illustrating a method according to the invention for authenticating a central unit located in a motor vehicle, the central unit being connected to a peripheral wheel unit fastened to a wheel of the vehicle; and
[0027] [ Figure 2 ] is a functional schematic diagram showing the reprogramming of the peripheral wheel unit after this authentication. [Specific implementation method]
[0028] Figure 1 A central unit 2 in a motor vehicle is shown, which forms a client with a central unit identifier 4 and one peripheral wheel unit 6 on each wheel, which peripheral wheel unit comprises a pressure sensor and a temperature sensor of the wheel tire and has a peripheral wheel unit identifier 8 and a symmetrically shared specific encryption key 10 recorded during the manufacture of the unit. The central unit 2 and the peripheral wheel unit 6 use in particular Standards communicate with each other.
[0029] An Internet network 14 using a radio link allows the central unit 2 to connect to a secure external server 12 containing a database comprising, for each peripheral wheel unit 6 , its identifier 8 and its shared encryption key 10 .
[0030] The method for authenticating the central unit 2 to allow sensitive operations to be performed on the peripheral wheel unit 6 comprises a first step 20 of using the central unit identifier 4 and a password to make the central unit recognized by one specific peripheral wheel unit 6 and to allow the connection to be accepted.
[0031] In parallel, the central unit 2 is connected to the server 12 via a secure link 14, so that the server can identify in its database the identifier of the particular unit 6 in question. Advantageously, an HTTPS (HTTPS stands for Hypertext Transfer Protocol Secure) secure link is used, for example a link established using the identifier 4 of the central unit and a password.
[0032] In a second step 22 , the peripheral wheel unit 6 generates a new session code, which can in particular be a random session number (n), and communicates it to the central unit 2 .
[0033] In a third step 24, the central unit 2 transmits its identifier 4, the identifier 8 of the peripheral wheel unit 6 and the session number (n) to the server 12, requesting the server to prove its authentication in order to obtain management rights for the peripheral wheel unit. The server 12 then verifies in its database whether the central unit is authorized to communicate with the peripheral wheel unit using the respective identifiers 4, 8 of the central unit 2 and the peripheral wheel unit 6.
[0034] If the central unit 2 is authorized to communicate with the peripheral wheel unit 6, in a fourth step 26, the server 12 performs a first encryption using the shared encryption key 10 (identified by the identifier 8 of the peripheral wheel unit) and the session number (n) to form a random and shared dynamic temporary first encryption key 28.
[0035] Then, in a fifth step 30 , the server 12 performs a second encryption using the identifier 4 of the central unit and the dynamic temporary first encryption key 28 in order to generate encrypted central server information 32 forming the authentication proof.
[0036] In a sixth step 34, the server 12 transmits the encrypted authentication proof information 32 to the central unit 2. In a seventh step 36, the central unit 2 in turn transmits the encrypted authentication proof information 32 to the specific unit 6.
[0037] While the secure server 12 is performing operations, in the eighth step 50, the peripheral wheel unit 6 performs the same steps as the fourth step, i.e., the server 12 performs the first encryption 26, by using its shared encryption key 10 and its session number (n) to form a temporary second encryption key 38. Then, in the ninth step 40, the peripheral wheel unit 6 reversely decrypts the second encryption of the fifth step 30 using the temporary second encryption key 38 and the encrypted authentication proof information 32 to obtain a decrypted identifier 42.
[0038] In a final tenth step 44, the peripheral wheel unit 6 compares the decrypted identifier 42 with the central unit identifier 4 and, if the two identifiers coincide, grants the central unit authentication. In this way, the remote security server 12 can verify the authentication of the central unit 2, which is then authorized to perform sensitive operations on the peripheral wheel unit 6, such as reprogramming it, with a high level of security and confidentiality.
[0039] In this way, the central unit 2 can subsequently provide the certificate to the peripheral wheel unit 6 again, without having to resort to the server 12, but only during the same communication session with the peripheral wheel unit. In this way, an outsider who wants to crack the system by seeking a connection during the next session cannot provide the certificate again and impersonate themselves as a client.
[0040] Figure 2 A secure server 12 is shown generating and hosting a dynamic private encryption key 60 that is used in an encryption operation 66 to encrypt a software source file 62, resulting in an encrypted file 64 that is loaded into the peripheral wheel unit 6. In any case, the server 12 retains the same image of the file as exists in the peripheral wheel unit 6. In particular, the dynamic private encryption key 60 may be unique and may be used to encrypt a single source file 62 or may be used to encrypt each file.
[0041] After the above series of authentications are performed on the central unit 2 , the central unit 2 obtains the administrator status, and the dynamic temporary first encryption key 28 is shared between the server 12 and the peripheral wheel unit 6 .
[0042] In a following step 70 , the server 12 encrypts the dedicated encryption key 60 using the shared dynamic temporary first encryption key 28 , thereby obtaining a new encryption key 72 that can be shared with the peripheral wheel unit 6 .
[0043] In a subsequent step 78 , the server 12 delivers the encrypted file 64 and the new encryption key 72 to the central unit 2 , which in turn delivers them to the peripheral wheel unit 6 in a subsequent step 80 .
[0044] In the following step 84, the peripheral wheel unit 6 uses the new encryption key 72 and the new shared dynamic encryption key 28 to form a dedicated encryption key 60 that is identical to the key held by the server 12. Finally, in the following step 86, the peripheral wheel unit 6 uses the dedicated encryption key 60 to decrypt the encrypted file 64 by performing the reverse operation of the encryption operation 66 previously performed by the server 12 to deliver the source file 62. The source file 62 is then verified using a checksum and then programmed into the memory of the peripheral wheel unit 6 for use.
[0045] The principle of the method according to the invention is to always use the same dedicated encryption key 60 to encode and decode the file 62, which avoids systematic encoding and decoding stages. Since the dedicated encryption key 60 is unknown to the peripheral wheel unit 6, the new encryption key 72 is transmitted encrypted by means of the shared dynamic encryption key 28 advantageously created during the authentication stage.
[0046] Decryption of the encryption key 72 is not possible on the central unit 2, since the cracker does not possess the shared dynamic temporary encryption key 28 created after authentication. As long as the cracker does not know the private encryption key 60, the method remains secure.
[0047] Advantageously, encryption and decryption are performed according to AES-128 (AES stands for Advanced Encryption Standard).
[0048] The authentication method according to the invention is particularly suitable for monitoring tires of motor vehicles in order to signal a fault to a user or repairer or to prevent a fault from occurring. The authentication method also allows motor vehicle manufacturers or tire manufacturers to receive information on external servers in order to track their products and improve quality.
Claims
1. A method for authenticating the right of a central unit (2) of a user to communicate bidirectionally by radio with one or more peripheral wheel units (6), the one or more peripheral wheel units performing measurements on the tires of the wheels of a motor vehicle, the measurement results of which are transmitted to the central unit (2) in order to perform sensitive operations on the peripheral wheel units, each central unit (2) and peripheral wheel unit (6) having a specific identifier (4, 8), the method using a secure external server (12) via the Internet (14) having in a database the identifiers (8) of the peripheral wheel units (6) and a symmetric encryption key (10) shared with each peripheral wheel unit (6), characterized in that The method comprises the following consecutive steps: - in a first step (20), the central unit (2) makes itself identifiable to each peripheral wheel unit (6) using its identifier (4) and a password, while in parallel the central unit (2) establishes a secure link (14) with the server (12) by authenticating itself so that the server can identify in its database the identifier (8) of the peripheral wheel unit (6) in question; - In a second step (22), the peripheral wheel unit (6) generates a new random session code (n) and communicates it to the central unit (2); - in a third step (24), the central unit (2) transmits its identifier (4), the identifier (8) of the peripheral wheel unit (6) and the session code (n) to the server (12) in order to request the server to prove its authentication in order to obtain management rights for the peripheral wheel unit (6); - in a fourth step (26), the server performs a first encryption using the shared encryption key (10) identified by the identifier (8) of the peripheral wheel unit and the session code (n) to form a random and shared dynamic temporary first encryption key (28), and then, in a fifth step (30), performs a second encryption using the identifier (4) of the central unit and the dynamic temporary first encryption key (28) to obtain encrypted central unit information (32) by means of an authentication certificate; - in a sixth step (34), the encrypted information (32) is transmitted to the central unit (2), and then, in a seventh step (36), the central unit (2) in turn transmits the encrypted information to the peripheral wheel unit (6); - in an eighth step (50), the peripheral wheel unit (6) performs a first encryption in parallel using its shared encryption key (10) and its session code (n), which is identical to the first encryption performed by the server (12) in the fourth step (26) to form a temporary second encryption key (38), and then, in a ninth step (40), the peripheral wheel unit performs a reverse decryption of the second encryption of the fifth step (30) using the temporary second encryption key (38) and the encrypted information (32) to obtain a decrypted identifier (42); and finally In a tenth step (44), the peripheral wheel unit (6) compares the decrypted identifier (42) with the identifier (4) of the central unit so that, if the two identifiers coincide, authentication is granted to the central unit (2).
2. The method according to claim 1, characterized in that In the next step (66), the secure server (12) that generates and hosts the dynamic private encryption key (60) uses the dynamic private encryption key to encrypt the software source file (62) to obtain an encrypted file (64), and then, in the next step (70), the server (12) uses the dynamic temporary first encryption key (28) to encrypt the private encryption key (60) to obtain a new encryption key (72), and then, in the next step (78), the server (12) delivers the encrypted file (64) and the new encryption key (72) to the central unit (2), and in the next step (80), the central unit (12) further delivers the encrypted file and the new encryption key to the peripheral wheel unit (6).
3. The method according to claim 2, characterized in that In the next step (84), the peripheral wheel unit (6) uses the new encryption key (72) and the new shared dynamic encryption key (28) to form a dedicated encryption key (60) that is identical to the encryption key held by the server (12), and then, in the next step (86), the peripheral wheel unit (6) uses the dedicated encryption key (60) to decrypt the encrypted file (64) by performing a reverse operation to the encryption operation (66) previously performed by the server (12) in order to deliver the source file (62).
4. The method according to claim 3, characterized in that The source file (62) is then verified using a checksum and then programmed into the memory of the peripheral wheel unit (6).
5. The method according to any one of the preceding claims, characterized in that The secure link (14) with the server (12) uses the HTTPS protocol, which stands for Hypertext Transfer Protocol Secure.
6. A method according to any one of the preceding claims, characterised in that Once the secure link (14) is established with the server (12), the server verifies in its database whether the central unit (2) is authorized to communicate with the peripheral wheel units (6).
7. A method according to any one of the preceding claims, characterised in that During a given communication session opened with the peripheral wheel unit (6), the central unit (2) again sends the encrypted information (32) to the peripheral wheel unit as authentication proof without using the server (12).
8. A system comprising a central unit (2) and peripheral wheel units (6) for performing measurements on the tires of wheels of a motor vehicle, the central unit and the peripheral wheel units being connected to each other by radio, characterized in that The system comprises apparatus for implementing the method as claimed in any one of the preceding claims.
9. A motor vehicle comprising a central unit (2) and peripheral wheel units (6) for performing measurements on the tires of the wheels of the vehicle, characterized in that The motor vehicle comprises equipment for carrying out the method as claimed in any one of claims 1 to 7.