Protecting Network Timing from Byzantine Attacks within Time-Sensitive IoT Networks
Research Problem
Ensuring network time synchronization is super important for time-sensitive IoT networks such as 5G and automotive Ethernet because they have very stringent time synchronization requirements and failing to meet them (even for a millisecond-level desynchronization) can cause significant system performance degradation.
Technically, precision time protocol (PTP) is the widely-used network timing protocol that ensures time synchronization for many distributed networks.
PTP Testbed.
In this research, we first propose a powerful insider time shifting attack launched by a malicious PTP client that is able to gradually shift the system time of an arbitrarily chosen victim node, even when the network is protected by the existing authentication mechanisms.
Time shifting attack results over PTP implementation PTPD and LinuxPTP. The overall trend shows the effective manipulation of the victim clock offset.
As a countermeasure, we propose a multi-source time synchronization mechanism named MS-PTP that aggregates the timing measurements of multiple sources. We devise a Byzantine resilient aggregation mechanism, which can defend Byzantine timing attacks when less than one-third of the sources are affected and overcomes unavoidable benign noise during the timing measurement process.
We provide a mathematical guarantee for the maximum error of our mechanism and validate the effectiveness of our mechanism on hardware testbeds.
Results
We verify the consequence of our attack on a real Turtlebot robotic platform demonstrating that the robots will go to the wrong trajectories when the attack is launched.
The consequence of de-synchronization attack on Turtlebot3.
We implement our defense mechanism on our PTP hardware testbed and the results show that our proposed defense can effectively defend against various timing attacks.
Our mechanism is compatible with the current industrial PTP standard.
MS-PTP accuracy performance under attack (𝑐𝑢 – cumulative delay, 𝑐𝑠 – constant delay, 𝑟𝑑 – random delay).
Reference
Shanghao Shi, Yang Xiao, Changlai Du, Md Hasan Shahriar, Ao Li, Ning Zhang, Y. Thomas Hou, and Wenjing Lou. 2023. MS-PTP: Protecting Network Timing from Byzantine Attacks. In Proceedings of the 16th ACM Conference on Security and Privacy in Wireless and Mobile Networks (WiSec 23). Association for Computing Machinery, New York, NY, USA, 61–71. [PDF]
