CAN Bus Intermediary for Source-Aware Message Validation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The CAN bus architecture lacks source information in bus messages, making it difficult to identify and filter messages from unsecured devices like infotainment systems, which poses a security risk as hackers can potentially control vehicle systems.
Innovation Solution
A bus control device is introduced between the input port and the CAN bus, which creates a notification message with source information, allowing an intrusion detection device to validate messages and optionally block or reconstruct them, ensuring only valid messages are transmitted on the common bus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bus control device is introduced to add source information to messages, then security is improved, but device complexity increases
Solution Approach 1:
The bus control device serves as an intermediary component positioned between the input port and the CAN bus. It intercepts messages from unsecured devices, adds source information to create notification messages, and forwards them to the CAN bus. This intermediary approach enables security enhancement without requiring modification of existing CAN bus architecture or devices.
Solution Approach 2:
The system segments the message handling function by separating the original message transmission from the security validation function. The bus control device creates a duplicate notification message with source information while the original message continues through the CAN bus. This segmentation allows security features to be added without disrupting the existing CAN bus communication flow.
2Reliability
If message validation is implemented to block malicious messages, then security is improved, but message transmission time increases
Solution Approach 1:
The bus control device performs preliminary action by adding source information to messages before they are transmitted on the CAN bus. This pre-processing of message data allows receiving devices to quickly identify and validate message sources without requiring complex real-time analysis during message reception, thereby minimizing transmission delays.
Solution Approach 2:
The system creates a copy of the original message with added source information (notification message) that travels alongside the original message on the CAN bus. This copying approach allows the validation function to operate on the notification message while the original message maintains its original transmission characteristics and timing, preventing validation overhead from delaying critical message delivery.
3Loss of information
If source information is added to messages, then message identification capability is improved, but information loss in original protocol is prevented
Solution Approach 1:
The bus control device acts as an intermediary that adds source information to messages without modifying the original CAN bus message structure. By creating separate notification messages that contain source information while preserving the original message format, the system prevents information loss about message origins while maintaining compatibility with existing CAN bus protocols and devices.
Data Source
AI summary
A bus control device is enabled for placement between an input port to which a suspect device would be connected and the bus. In this manner, all message received from the suspect device, such an infotainment system, must pass through the bus control device. A separate intrusion detection device is coupled to the bus. The bus control device is arranged to output a notification message to the intrusion detection device, the notification message comprising information about the received message. The intrusion detection device is arranged to determine the validity of the received message responsive to the received notification message.