# US 12,603,772 B2 · Vehicle diagnostic system, method, and apparatus

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- Number: US 12,603,772 B2
- Document ID: US12603772B2
- Status: Granted
- Kind: B2
- Application number: 18/330,030
- Filed: 2023-06-06
- Published: 2023-10-05
- Granted: 2026-04-14
- Earliest claimed: 2020-12-08
- Assignees: Shenzhen Yinwang Intelligent Technologies Co., Ltd.
- Applicants: Shenzhen Yinwang Intelligent Technologies Co., Ltd.
- Inventors: Feng Geng; Yong Li; Pingping Yi; Min Li
- Web page: https://patentgrep.com/patent/US12603772B2

## CPC

- H04L 9/088: {Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms (network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068)}
- G07C 5/0808: {Diagnosing performance data (testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005)}
- H04L 9/0631: {Substitution permutation network [SPN], i.e. cipher composed of a number of stages or rounds each involving linear and nonlinear transformations, e.g. AES algorithms}
- H04L 9/0637: {Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]}
- H04L 9/0643: {Hash functions, e.g. MD5, SHA, HMAC or f9 MAC}
- H04L 9/0891: {Revocation or update of secret information, e.g. encryption key update or rekeying}
- H04L 9/32: including means for verifying the identity or authority of a user of the system {or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials}
- H04L 63/068: {using time-dependent keys, e.g. periodically changing keys (cryptographic mechanisms or cryptographic arrangements for controlling usage of secret information H04L9/088)}
- H04W 4/48: for in-vehicle communication
- H04W 12/04: Key management, e.g. using generic bootstrapping architecture [GBA]
- G07C 2205/02: using a vehicle scan tool
- H04L 2209/84: Vehicles
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

The vehicle diagnostic system includes a key management system and a to-be-diagnosed unit. The key management system receives a key authorization request sent by a diagnostic device, generates a temporary key based on the key authorization request, and sends a key authorization response to the diagnostic device. The key authorization response carries the temporary key. The key management system configures the temporary key for the to-be-diagnosed unit, so that the diagnostic device and the to-be-diagnosed unit complete a diagnostic based on the temporary key and obtain a diagnostic result. The temporary key is independent of a long-term key in a vehicle. The temporary key is configured to complete the vehicle diagnostic, so that the diagnostic device can be prevented from accessing the long-term key in the vehicle as much as possible.

## Claims

### Claim 1

A vehicle diagnostic system in a vehicle and comprising:
a diagnostic device configured to send a key authorization request;
a to-be-diagnosed device; and
a key management system configured to:
receive the key authorization request from the diagnostic device;
generate a temporary key based on the key authorization request, wherein the temporary key is independent of a long-term key in the vehicle and is for performing diagnostics;
send a key authorization response to the diagnostic device, wherein the key authorization response comprises the temporary key; and
configure the temporary key for the to-be-diagnosed device in the vehicle, wherein the diagnostic device and the to-be-diagnosed device perform a diagnostic based on the temporary key,
wherein the diagnostic device is further configured to:
receive the key authorization response from the key management system;
encrypt to-be-diagnosed information using the temporary key to generate a diagnostic request; and
send the diagnostic request to the to-be-diagnosed device,
wherein the to-be-diagnosed device is configured to:
obtain the temporary key from the key management system;
receive the diagnostic request from the diagnostic device;
decrypt the diagnostic request using the temporary key to obtain the to-be-diagnosed information;
perform a diagnostic operation based on the to-be-diagnosed information to obtain a diagnostic result; and
send the diagnostic result to the diagnostic device, and
wherein the diagnostic device is further configured to receive the diagnostic result from the to-be-diagnosed device.

### Claim 2 (depends on 1)

The vehicle diagnostic system of claim 1, wherein the key management system is further configured to:
periodically receive, from the diagnostic device, a security heartbeat message within a validity duration corresponding to the temporary key; and
set, when the security heartbeat message is not received within a preset period duration, the temporary key in the to-be-diagnosed device to be ineffective.

### Claim 3 (depends on 2)

The vehicle diagnostic system of claim 2, wherein the security heartbeat message comprises first verification information, wherein the first verification information is based on at least one piece of characteristic information used when the temporary key is generated, and wherein the key management system is further configured to:
generate, when the diagnostic device is received within the preset period duration, second verification information based on the at least one piece of characteristic information used when the temporary key is generated; and
continue to set, when determining that the second verification information matches the first verification information, the temporary key to be effective,
wherein the diagnostic device is further configured to:
generate a first random value; and
send the first random value to the key management system,
wherein the key management system is further configured to:
generate a second random value; and
send the second random value to the diagnostic device,
wherein the at least one piece of characteristic information comprises at least one of an initial key, a feature identifier, the first random value, or the second random value that is preset, wherein the feature identifier indicates the to-be-diagnosed device.

### Claim 4 (depends on 3)

The vehicle diagnostic system of claim 3, wherein the key authorization request comprises at least one piece of characteristic information, wherein the at least one piece of characteristic information comprises at least one of the first random value, the feature identifier, or an authorization code, wherein the authorization code indicates the diagnostic device, and wherein the key management system is configured to:
encrypt the at least one piece of characteristic information using a first symmetric key to generate a transmission security key;
encrypt the temporary key using the transmission security key to generate a ciphertext; and
generate the key authorization response based on the ciphertext,
wherein the diagnostic device is configured to perform decryption using the transmission security key and the ciphertext to obtain the temporary key.

### Claim 5 (depends on 1)

The vehicle diagnostic system of claim 1, wherein the key management system is configured to set the temporary key in the to-be-diagnosed device to be ineffective after a validity duration corresponding to the temporary key expires.

### Claim 6 (depends on 5)

The vehicle diagnostic system of claim 5, wherein the validity duration corresponding to the temporary key is pre-configured, indicated by the key authorization request, or corresponds to a time period between a diagnostic start and a diagnostic end.

### Claim 7 (depends on 1)

The vehicle diagnostic system of claim 1, wherein the to-be-diagnosed device is pre-configured or indicated by the key authorization request.

### Claim 8 (depends on 1)

The vehicle diagnostic system of claim 1, wherein the to-be-diagnosed device is configured to:
receive temporary key effective information from the key management system, wherein the temporary key effective information comprises the temporary key; and
store the temporary key in a random-access memory (RAM) based on the temporary key effective information.

### Claim 9 (depends on 8)

The vehicle diagnostic system of claim 8, wherein the to-be-diagnosed device is further configured to:
receive temporary key ineffective information from the key management system in the vehicle, wherein the temporary key ineffective information comprises the temporary key; and
delete, based on the temporary key ineffective information, the temporary key stored in the RAM.

### Claim 10

A vehicle diagnostic apparatus, comprising:
at least one memory configured to store program instructions; and
one or more processors coupled to the at least one memory and configured to execute the program instructions to cause the vehicle diagnostic apparatus to:
receive, from a diagnostic device, a key authorization request comprising at least one piece of characteristic information, the at least one piece of characteristic information comprises an authorization code that indicates the diagnostic device;
generate a temporary key based on the key authorization request, wherein the temporary key is independent of a long-term key in a vehicle;
encrypt the at least one piece of characteristic information using a first symmetric key to generate a transmission security key;
encrypt the temporary key using the transmission security key to generate a ciphertext;
generate a key authorization response based on the ciphertext, wherein the key authorization response comprises the temporary key;
send the key authorization response to the diagnostic device, wherein the diagnostic device is configured to perform decryption using the transmission security key and the ciphertext to obtain the temporary key; and
configure the temporary key for a to-be-diagnosed device in the vehicle,
wherein the diagnostic device and the to-be-diagnosed device perform a diagnostic based on the temporary key.

### Claim 11 (depends on 10)

The vehicle diagnostic apparatus of claim 10, wherein the one or more processors are further configured to execute the program instructions to cause the vehicle diagnostic apparatus to set, when a security heartbeat message from the diagnostic device is not received within a preset period duration, the temporary key in the to-be-diagnosed device to be ineffective, wherein the security heartbeat message is periodically received from the diagnostic device within a validity duration corresponding to the temporary key.

### Claim 12 (depends on 10)

The vehicle diagnostic apparatus of claim 10, wherein the one or more processors are further configured to execute the program instructions to cause the vehicle diagnostic apparatus to set the temporary key in the to-be-diagnosed device to be ineffective after a validity duration corresponding to the temporary key expires.

### Claim 13 (depends on 12)

The vehicle diagnostic apparatus of claim 12, wherein the validity duration corresponding to the temporary key is pre-configured, indicated by the key authorization request, or corresponds to a time period between a diagnostic start and a diagnostic end.

### Claim 14 (depends on 10)

The vehicle diagnostic apparatus of claim 10, wherein the to-be-diagnosed device is pre-configured or indicated by the key authorization request.

### Claim 15

A vehicle diagnostic apparatus, comprising:
at least one memory configured to store program instructions; and
one or more processors coupled to the at least one memory and configured to execute the program instructions to cause the vehicle diagnostic apparatus to:
send a key authorization request to a key management system in a vehicle to generate a temporary key and configure the temporary key for a to-be-diagnosed device in the vehicle, wherein the temporary key is independent of a long-term key in the vehicle;
receive a key authorization response from the key management system, wherein the key authorization response comprises the temporary key;
encrypt to-be-diagnosed information using the temporary key to generate a diagnostic request;
send the diagnostic request to the to-be-diagnosed device; and
initiate a diagnostic operation on the to-be-diagnosed device based on the diagnostic request.

### Claim 16 (depends on 15)

The vehicle diagnostic apparatus of claim 15, wherein the one or more processors are further configured to execute the program instructions to cause the vehicle diagnostic apparatus to send a security heartbeat message to the key management system based on a preset period duration within a validity duration corresponding to the temporary key, wherein the key management system uses the security heartbeat message to continue to set the temporary key to be effective.

### Claim 17 (depends on 16)

The vehicle diagnostic apparatus of claim 16, wherein the one or more processors are further configured to execute the program instructions to cause the vehicle diagnostic apparatus to:
generate first verification information based on at least one piece of characteristic information used when the temporary key is generated; and
generate the security heartbeat message based on the first verification information, wherein the first verification information is used by the key management system to verify the security heartbeat message,
wherein the vehicle diagnostic apparatus is further configured to:
generate a first random value; and
send the first random value to the key management system,
wherein the key management system is further configured to:
generate a second random value; and
send the second random value to the vehicle diagnostic apparatus,
wherein the at least one piece of characteristic information comprises at least one of an initial key, a feature identifier, the first random value, or the second random value that is preset, wherein the feature identifier indicates the to-be-diagnosed device.

### Claim 18 (depends on 16)

The vehicle diagnostic apparatus of claim 16, wherein the validity duration corresponding to the temporary key is pre-configured, indicated by the key authorization request, or corresponds to a time period between a diagnostic start and a diagnostic end.

### Claim 19 (depends on 15)

The vehicle diagnostic apparatus of claim 15, wherein the to-be-diagnosed device is pre-configured.

### Claim 20 (depends on 15)

The vehicle diagnostic apparatus of claim 15, wherein the to-be-diagnosed device is indicated by the key authorization request.