Lead University: Lehigh University
PI: Rick Blum

The ability to precisely synchronize clocks among distributed components is critical in fields such as electrical power systems, industrial automation, and telecommunication. One of the popular timing synchronization protocols is the IEEE 1588 standard (also referred to as the “Precise Time Protocol” (PTP)) which can provide microsecond-level sychronization accuracy for packet-switched networks. The packet-switched networks inherently suffer from unpredictable network traversal times, a phenomenon referred to as Packet Delay Variation (PDV). PTP adopts a straightforward approach, wherein a slave node synchronizes to the master node via two-way timing message exchanges. One of the most effective attacks in PTP is the delay attack, wherein a malicious attacker deliberately delays the transmission of time synchronization messages in order to degrade the accuracy of the packet-based synchronization schemes. This type of attack cannot be typically countered using conventional security measures. Under previous PITA grants, the statistical nature of PDV was studied under many different network conditions, theoretical performance limits for PDV cancellation were derived, and new PDV cancellation methods were developed for scenarios when a slave node tries to synchronize to a single master node. In the current PITA grant, various existing approaches addressing the problem of delay attack were studied and analyzed. Some preliminary results on theoretical performance limits on the best acheivable performance using multiple masters in the presence of delay attacks were derived, and a new method for PDV cancellation in the presence of delay attacks using multiple masters is being developed. Synchronizing the slave node in the presence of delay attacks using multiple master nodes when complete information of the distribution of the PDV is unavailable was not considered in the previous work. This would be studied under the requested funding. The project is a collaboration between the Lehigh team and Netizen Corporation, a strong local company focused on cybersecurity.