ECU Certificate Chain Authentication for Secure Function Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing number of electronic control units (ECUs) in vehicle systems leads to issues such as invalid replacement of ECUs, unauthorized intrusion of ECU programs, and malicious tampering of ECU key data, resulting in a low security level due to the vulnerability of symmetric keys.
Innovation Solution
A vehicle-mounted device control method that uses digital certificates and private keys for security authentication between ECUs, allowing ECUs to verify the validity of each other's certificates and determine allowed functions based on certificate chain matching degrees, eliminating the need to distinguish between main and key ECUs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If symmetric key technology is used for security authentication between ECUs, then authentication can be implemented, but the security level is low due to vulnerability of symmetric keys to malicious leakage or unauthorized tampering
Solution Approach 1:
The patent transitions from symmetric key technology to asymmetric encryption technology (digital certificates and private keys), where the first ECU holds both a first digital certificate and a first private key, while the second ECU holds only a second digital certificate. This asymmetric structure eliminates the vulnerability of symmetric keys while maintaining authentication capability.
2Reliability
If digital certificates are used for security authentication, then security level is improved, but storage space requirements increase
Solution Approach 1:
The patent applies different storage requirements to different ECUs based on their roles. The first ECU (control device) stores both a first digital certificate and a first private key, while the second ECU (controlled device) stores only a second digital certificate. This localized differentiation reduces overall storage requirements compared to storing complete certificate pairs in all ECUs.
3Ease of operation
If unified authentication results are used for all ECUs, then authentication process is simplified, but ECU resource waste occurs and user experience deteriorates
Solution Approach 1:
The patent implements dynamic authentication results based on certificate chain matching degrees. The second ECU determines allowed functions by comparing the matching degree between its own certificate chain and the first ECU's certificate chain. This dynamic approach allows different authentication outcomes for different ECU pairs, preventing resource waste while maintaining operational simplicity through automated determination.
4Adaptability or versatility
If symmetric key technology is used, then authentication between ECUs can be implemented, but the system cannot adapt to ECU replacement or reuse scenarios
Solution Approach 1:
The patent pre-establishes certificate chains for each ECU before deployment. When an ECU is replaced or reused, the new ECU brings its own pre-configured certificate chain, allowing it to be automatically recognized and authenticated by the first ECU without requiring system reconfiguration. This preliminary preparation enables seamless ECU replacement and reuse.
Data Source
AI summary
A vehicle-mounted device control method includes a digital certificate to perform security authentication between electronic control units (ECUs), and a function that is currently allowed to be accessed is determined based on a matching degree of certificate chains. The method comprises transmitting the digital certificate and an encrypted instruction between the ECUs, determining accessible functions based on the matching degree of certificate chains, and either starting, or failing to start, a function based on permission to access the function.