In-Vehicle Counter Value Synchronization via Segmented Transmission
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Solution Overview
Problem
In conventional message authentication systems for in-vehicle networks, count value synchronization is inefficient due to the need for resynchronization after message filtering, leading to potential mismatches and increased data traffic, especially in protocols like CAN where data capacity is limited.
Innovation Solution
A communication system that divides the counter value into high-order and low-order values, where the high-order value is transmitted separately in a synchronization message to facilitate rapid resynchronization without increasing data traffic, ensuring security by verifying the integrity of messages using message authentication codes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire count value is transmitted for resynchronization, then security is ensured through complete verification, but data traffic increases and transmission time extends
Solution Approach 1:
The count value is segmented into high-order count value and low-order count value. The low-order count value is transmitted with normal messages for routine verification, while only the high-order count value is transmitted during resynchronization. This segmentation reduces the data traffic during resynchronization while maintaining security through hierarchical verification.
2Reliability
If resynchronization is performed by broadcasting initial counter values, then count value synchronization is achieved, but the process takes long time due to data transmission requirements
Solution Approach 1:
By segmenting the count value into high-order and low-order parts, the patent enables transmission of only the high-order count value during resynchronization. This significantly reduces the data transmission time while ensuring synchronization accuracy, as the high-order value contains the critical synchronization information.
Solution Approach 2:
The patent changes the parameter being transmitted during resynchronization from the complete count value to only the high-order count value. This parameter change reduces transmission time while maintaining synchronization accuracy, as the high-order value is sufficient for re-establishing count value alignment between transmitter and receiver.
3Reliability
If MAC is added to count value for secure transmission, then security against foreign attacks is ensured, but data amount transmitted increases
Solution Approach 1:
The patent applies segmentation by transmitting only the high-order count value during resynchronization rather than the complete count value with MAC. The low-order count value is handled separately in normal message transmission. This reduces the total data amount transmitted while maintaining security through the hierarchical verification process.
Data Source
AI summary
A communication system includes multiple nodes connected with each other. Each of the multiple nodes generates a message authentication code using a count value of a counter. The multiple nodes include a transmission node and a reception node. The count value of the counter is includes a high-order count value and a low-order count value. In the transmission node, a normal message generation portion generates a normal message to include a transmission data, the low-order count value, and the message authentication code, and a synchronization message generation portion generates a synchronization message. In the reception node, a message verification portion verifies the received normal message, a resynchronization request portion transmits a resynchronization request of the counter to the transmission node, and a count value update portion updates the high-order count value stored in the reception count value storage portion when the synchronization message is received.