Bus Controller Message Filtering for Vehicle ECU Security
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Solution Overview
Problem
Vehicle electronic control systems, increasingly complex and interconnected, are vulnerable to security attacks due to inadequate attention to their security environment, with malicious platforms potentially reprogramming controllers and sending harmful messages, necessitating specific security enhancements that may lead to duplication of efforts among Original Equipment Manufacturers (OEMs).
Innovation Solution
Implementing a rule-based message filter in the firmware of a bus controller, protected from unauthorized manipulation, with secure message filtering rules verified for authenticity, using a trusted rule-signing key and digital signatures to ensure only trusted rules are applied, and limiting programmability access to the bus controller firmware to enhance security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If message filtering rules are made programmable and updateable, then system adaptability and responsiveness to new threats improve, but security vulnerability increases due to potential unauthorized manipulation
Solution Approach 1:
The system separates message filtering functionality into distinct components: updateable filtering rules stored in memory and immutable verification logic embedded in firmware. This segmentation allows the filtering rules to be adaptable while the verification mechanism maintains security integrity, resolving the contradiction between programmability and security.
Solution Approach 2:
A firmware-based verification mechanism acts as an intermediary between message filtering rule updates and their implementation. This intermediary verifies the authenticity and integrity of filtering rules before they take effect, enabling adaptability while preventing unauthorized manipulation through cryptographic verification.
2Reliability
If security enhancements are implemented at each individual embedded controller, then security coverage improves, but device complexity and manufacturing overhead increase
Solution Approach 1:
The patent implements a universal security mechanism where firmware verification logic is deployed across all bus controllers in the vehicle network. This single approach provides security coverage for multiple controllers simultaneously, reducing manufacturing overhead and complexity compared to implementing different security enhancements at each individual controller.
Solution Approach 2:
The system changes the state of security from static (presumed safe) to dynamic (verified through cryptographic parameters). By introducing verification flags and authenticity checks as configurable parameters in the firmware, the system achieves comprehensive security coverage without significantly increasing controller complexity.
3Reliability
If firmware programmability is limited to enhance security, then security integrity improves, but system adaptability and update capability deteriorate
Solution Approach 1:
The firmware is segmented into immutable verification logic and updateable filtering rules. The verification logic portion remains fixed and cannot be modified, ensuring security integrity, while the filtering rules portion can be updated through verified update mechanisms, maintaining adaptability without compromising firmware security.
Solution Approach 2:
The firmware performs preliminary verification of filtering rule authenticity before applying updates. This preliminary action ensures that only authorized and intact filtering rules are implemented, maintaining firmware security while enabling safe adaptability through controlled update capability.
Data Source
AI summary
A method according to one embodiment includes the operations of configuring a host processor to receive a message filtering rule, the host processor associated with a vehicle; configuring a bus controller to verify authenticity of the message filtering rule, wherein the bus controller is programmed through an interface, the interface inaccessible from the host processor; filtering messages from the host processor using the verified message filtering rule, wherein the filtering is performed by the bus controller; and transmitting the filtered messages from the bus controller over a bus to one or more electronic control units (ECUs), the ECUs communicatively coupled to the bus.