CAN Transceiver Secure Bus Idle Detection
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Solution Overview
Problem
In Controller Area Network (CAN) bus systems, malicious devices can disrupt communication by creating glitches, leading to incorrect bus idle detection, which can allow them to manipulate the bus and prevent proper communication among nodes.
Innovation Solution
A secure transceiver is introduced that monitors CAN bus data frames for CRC or error delimiters, allowing only a predetermined data pattern to be sent until the bus is idle, and invalidates or suppresses frames that do not conform to this pattern, thereby preventing malicious interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a transceiver allows any data pattern to be sent on the CAN bus, then the ease of operation is improved, but the reliability deteriorates due to malicious devices disrupting communication
Solution Approach 1:
The transceiver is configured to detect delimiters (CRC delimiter, error delimiter, or error signal) in advance and preemptively restrict data transmission to predetermined patterns only after delimiter detection. This preliminary action prevents malicious devices from sending arbitrary data patterns that could disrupt bus idle detection, thereby maintaining communication integrity while allowing normal transmission flexibility.
2Reliability
If a transceiver monitors and validates data frames, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The transceiver implements localized validation by monitoring only specific critical portions of the CAN frame (delimiter detection) rather than validating the entire data frame. The validation logic is confined to checking whether data patterns follow predetermined rules after delimiter detection, without requiring comprehensive analysis of all frame contents. This localized approach improves bus idle detection accuracy while minimizing the increase in device complexity.
3Reliability
If a transceiver restricts data transmission to predetermined patterns, then the reliability is improved, but the adaptability deteriorates
Solution Approach 1:
The transceiver applies partial restriction by allowing predetermined data patterns (which cover normal operational needs) while blocking only the excessive arbitrary patterns that malicious devices might send. The restriction is not absolute but targeted at specific problematic scenarios, thereby maintaining communication security while preserving sufficient data transmission flexibility for legitimate applications.
Data Source
AI summary
A transceiver for sending and receiving data from a controller area network (CAN) bus is disclosed. The transceiver includes a microcontroller port, a transmitter and a receiver. The transceiver is configured to detect a CRC delimiter or an error signal in a CAN frame and after the detection, allow a microcontroller coupled with the microcontroller port to only send a predetermined data pattern until a bus idle is detected.