Vehicle Key Management System for Secure Communication

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Solution Overview

Problem

Current vehicle communication systems lack a secure and efficient method for key management and authentication, particularly in establishing trusted communication paths between vehicles and external services, leading to vulnerabilities in data integrity and security.

Innovation Solution

A method for generating and managing cryptographic keys within the vehicle manufacturer's sphere of influence, creating a circle of trust through deterministic derivation of keys from a master key, enabling secure key distribution and authentication using asymmetric and symmetric keys, with a centralized key management system and public key infrastructure (PKI) for bidirectional communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cryptographic key material is provided for each vehicle function using standalone solutions or existing systems, then cryptographic protection is achieved, but system complexity and key management difficulty increase

Engineering Contradiction:
Improvecryptographic protectionVSAvoidkey management system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple cryptographic key management functions into a single centralized key management system. Instead of using separate standalone solutions for each vehicle function, the system consolidates key generation, storage, distribution, and rotation operations into one unified infrastructure that serves all cryptographic needs across the vehicle and its communication partners.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The key management system is designed to be universal, supporting multiple cryptographic functions and communication scenarios through a single system. It can manage symmetric keys for efficient communication, asymmetric key pairs for authentication, and rotate keys across different vehicle functions and external service providers without requiring function-specific key management solutions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If existing cryptographic systems are used for vehicle functions, then implementation is straightforward, but they are not ideally suited for vehicle-specific authentication and communication security requirements

Engineering Contradiction:
Improvesystem implementationVSAvoidauthentication security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent adapts cryptographic systems to meet vehicle-specific requirements by implementing localized security measures tailored to automotive contexts. This includes generating vehicle-specific key pairs, implementing authentication protocols designed for vehicle-external service communication, and managing keys in a way that addresses the specific threat model and communication patterns of modern vehicles.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes cryptographic parameters and configurations to suit vehicle applications. It implements vehicle-specific key derivation functions, custom authentication protocols, and key rotation schedules that differ from generic cryptographic systems, thereby achieving both ease of implementation and high security suitability for automotive environments.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a centralized key management system with deterministic key derivation is implemented, then key distribution and authentication become more secure, but the system requires complex infrastructure within the manufacturer's sphere of influence

Engineering Contradiction:
Improvekey distribution securityVSAvoidkey management infrastructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary key generation and distribution actions during vehicle manufacturing and initial setup. The master key is established beforehand, and all vehicle-specific cryptographic materials are derived and distributed in advance through secure channels, eliminating the need for complex real-time key management operations during vehicle operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a centralized key management system as an intermediary between the vehicle manufacturer and the vehicle. This intermediary handles all complex key generation, derivation, distribution, and rotation operations, thereby securing key distribution while managing the infrastructure complexity in a centralized location rather than distributing it across multiple vehicle systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If bidirectional authentication is implemented for all communication partners, then communication security is improved, but the authentication process becomes more time-consuming and complex

Engineering Contradiction:
Improvecommunication securityVSAvoidauthentication time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary authentication setup by pre-distributing public keys and authentication credentials to all communication partners during vehicle manufacturing or initial registration. This allows bidirectional authentication to proceed efficiently during actual communication by using pre-established trust relationships rather than performing full authentication rituals each time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The authentication process is segmented into different levels and scenarios. The system implements efficient authentication mechanisms for different communication partners (e.g., simplified authentication for trusted internal vehicle components versus more rigorous authentication for external service providers), thereby reducing overall authentication time while maintaining security where required.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3157281B1Method for secure communication of a vehicle
Publication Date: 2020.12.16 VOLKSWAGEN AG
  • EP3157281B1 patent drawingFigure 1
  • EP3157281B1 patent drawingFigure 2
  • EP3157281B1 patent drawingFigure 3

AI summary

The invention relates to a method for secure communication of a vehicle (14). The following steps are provided: - Generating a key pair (22) consisting of a private key and a public key and/or one or more symmetric keys for the vehicle (14) or for a control unit (28, 30, 32) of the vehicle (14) within the vehicle manufacturer's sphere of influence, - Generating an initial certificate (24) with the key pair (22), - Introducing the key pair (22) and the initial certificate (24) and/or the symmetric keys into the vehicle (14) or the control unit (28, 30, 32), - Authenticating the vehicle (14) or the control unit (28, 30, 32) to a new communication partner (38, 40) by generating a new key pair (50) for this communication channel and sending a signed message together with the certificate (24), and - Authenticating a new communication partner (38,40) to the vehicle or the control unit (28, 30, 32) with a signed message and a public key created by the new communication partner based on certification by the vehicle manufacturer.