In-Vehicle Network Counter Synchronization for Replay Attack Prevention
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Solution Overview
Problem
Existing onboard vehicle communication networks lack effective security measures, particularly in freshness value synchronization, leading to vulnerabilities such as replay attacks and complex implementation difficulties.
Innovation Solution
A method for secure onboard network communication that synchronizes freshness values monotonically within a vehicle lifecycle without additional synchronization mechanisms, using an N-bit integer counter and predetermined value increments to ensure freshness, reducing complexity and resource consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a timestamp scheme is used for freshness value synchronization, then the synchronization mechanism is simple, but clock jitter and timestamp synchronization exceptions cause receiver to fail to receive CAN messages, leading to system function security problems
Solution Approach 1:
The patent extracts the time-dependent element (timestamp) from the freshness value synchronization mechanism and replaces it with a counter-based approach. The sender maintains a counter that increments with each message, and the receiver synchronizes by receiving the counter value in messages rather than relying on timestamp comparisons. This removes the problematic timestamp synchronization while preserving the freshness verification functionality.
2Reliability
If a monotonic counter scheme is used for freshness value synchronization, then message reception reliability is improved, but implementation complexity increases and timely periodic synchronization cannot be guaranteed, resulting in enlargement of replay attack window
Solution Approach 1:
The patent merges the freshness value synchronization with the existing message transmission process. The counter value is included directly in the CAN messages that are already being transmitted for other purposes, eliminating the need for separate synchronization messages or additional communication overhead. This combines two functions (message transmission and freshness synchronization) into a single efficient process.
Solution Approach 2:
The receiver autonomously updates its local counter value based on the counter value received in incoming messages, without requiring external synchronization commands or complex coordination with the sender. Each received message automatically serves to synchronize the receiver's freshness value, making the system self-synchronizing and eliminating replay attack windows immediately.
3Reliability
If conventional security measures are deployed in CAN bus communication, then message authentication is improved, but the broadcast bus network architecture and message-oriented protocol make direct deployment difficult
Solution Approach 1:
The patent implements security at the local message level by adding a counter field to individual CAN messages rather than requiring system-wide architectural changes. Each message carries its own freshness indicator (counter value) that can be independently verified by the receiver. This localized approach to security is compatible with the existing broadcast CAN bus architecture and message-oriented protocol without requiring complex reconfiguration of the entire system.
Data Source
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AI summary
This application provides a secure onboard network communication method, an apparatus, and a device, to ensure that a freshness value is effectively synchronized within a vehicle lifecycle of a vehicle, and prevent a replay attack in onboard network communication. The device includes: a first processing module, configured to obtain an initial value of a first freshness value FV, obtain a second value based on the initial value, and refresh the initial value to the second value; a first sending module, configured to send a first message, where the first message includes the second value of the first FV; a first receiving module, configured to receive the first message; and a second processing module, configured to obtain an initial value of a second freshness value FV, and when a first condition is met, refresh the second FV to the second value, where the first condition includes a condition that the second value of the first FV is greater than or equal to a sum of the initial value of the second FV and a predetermined value.