UWB Communication Device Clock Verification for SS-TWR Security
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Solution Overview
Problem
Ultra-wideband (UWB) communication systems are vulnerable to clock-offset based attacks in single-sided two-way ranging (SS-TWR) methods, which can lead to inaccurate distance measurements and compromise the security of handsfree object access systems.
Innovation Solution
A communication device and method that measures and verifies the frequency offset correlation between its own clock and the counterpart clock during a UWB ranging session, using additional communication units like Bluetooth or reference clocks, to detect and counteract unidirectional and bidirectional clock-offset attacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If single-sided two-way ranging (SS-TWR) method is used for distance measurement, then resource consumption is reduced and operation is simplified, but security is compromised due to vulnerability to clock-offset based attacks
Solution Approach 1:
The patent applies preliminary action by measuring the frequency offset of the device clock before executing the ranging session, and using this measurement to verify the counterpart clock's frequency offset. This pre-measurement allows the system to detect potential clock-offset attacks before they can compromise the ranging result, thereby maintaining security while keeping the SS-TWR method simple and resource-efficient
2Reliability
If frequency offset measurement and verification is added to detect clock-offset attacks, then security is improved, but device complexity increases
Solution Approach 1:
The patent implements feedback by measuring the frequency offset of the device clock, communicating this measurement to the counterpart device, and receiving the counterpart's frequency offset measurement in return. Both devices then verify whether their respective frequency offset measurements are consistent with each other. This feedback mechanism enables security verification without requiring complex additional hardware, as it utilizes existing communication channels and processing capabilities
3Reliability
If double-sided two-way ranging (DS-TWR) method is used to achieve higher security, then security is improved, but resource consumption and complexity increase
Solution Approach 1:
The patent applies copying by using the frequency offset measurement approach from DS-TWR and adapting it for use in SS-TWR. Instead of implementing the full DS-TWR protocol which requires four message exchanges and two ranging results, the invention copies the essential security verification mechanism (frequency offset measurement and comparison) and applies it within the simpler SS-TWR framework, achieving comparable security with reduced resource consumption
Data Source
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AI summary
In accordance with a first aspect of the present disclosure, a communication device is provided, comprising: a communication unit configured to execute a time-of-flight ranging session with an external communication counterpart; a clock offset measurement unit configured to measure a frequency offset of a device clock, wherein said device clock is configured to be used by the communication unit when said ranging session is executed; a processing unit configured to determine whether the measured frequency offset of the device clock has a predefined correlation with a frequency offset of a counterpart clock, wherein said counterpart clock is configured to be used by the external communication counterpart when said ranging session is executed. In accordance with a second aspect of the present disclosure, a corresponding method of operating a communication device is conceived. In accordance with a third aspect of the present disclosure, a corresponding computer program is provided.