Accurate and secure clock synchronisation based on electric network frequency
Technology title
Accurate and secure clock synchronisation based on electric network frequency
Technology overview
This technology utilises the sine voltage waveform of a utility power grid to synchronise various nodes connected to the same grid. Experimental results show that minute fluctuations in the voltage cycle length encode fine-grained global time information. Building on this observation, a clock synchronisation approach has been developed that achieves sub-millisecond accuracy and is provably secure against packet delay attacks. The designer and operator of a system that relies on distributed grid-connected devices and their synchronised clocks are the target users of this technology. No other technologies in the marketplace can maintain the synchronisation of distributed devices’ clocks in the presence of attacks that delay the network transmissions of synchronisation packets.
Technology specifications
The technology enables secure time synchronisation for time-critical systems by using the electrical network voltage (ENV) signal from an alternating current (AC) utility power grid. Nodes connected to the same power grid can be synchronised using this signal, without relying on network-based timing messages.
The ENV signal is well-suited for this purpose because it is periodic, widely available, and consistent across locations within the same power grid. In addition, it is a physical signal that is difficult to manipulate or forge, providing an inherent level of security.
The technology exploits small, naturally occurring variations in the power grid signal, referred to as a time fingerprint. These variations arise from normal fluctuations in power generation and demand. By comparing time fingerprints captured at different nodes, the system can accurately align clocks across devices. Experimental validation shows that this approach enables reliable and secure clock synchronisation with high time accuracy.
Sector
This invention is applicable to time-critical systems. For example, industrial automation systems; grid-connected Internet of Things; smart meters in advanced metering infrastructures.
Market opportunity
Most smart sensor and actuator devices require synchronised clocks. Malicious activities that cause clock drifts of these smart sensors/actuators may lead to catastrophic consequences. This technology is applicable to all smart sensors and actuators that directly draw power from the alternating current power grid.
Applications
Key applications include industrial Internet of Things (IoT), industrial automation systems, manufacturing systems, advanced metering infrastructures, telecommunications equipment, and microprocessor systems.
Customer benefits
The technology provides secure, highly accurate time synchronisation using existing power grid signals, eliminating reliance on GPS or network-based timing and reducing vulnerability to timing attacks. Relevant technologies include products that implement standardised Network Time Protocol (NTP), Precision Time Protocol (PTP). However, NTP and PTP are susceptible to the attacks that delay the network transmissions of synchronisation packets. This technology can be integrated into the implementations of NTP and PTP to enhance their security.
Technology readiness level
TRL 5
Ideal collaboration partner
Ideal collaboration partners include vendors of systems that use NTP and/or PTP.
Collaboration mode
This technology is suitable for licensing.