The UK’s internet cables can hear ships – now the government wants the data
Key Points
- Fibre-optic sensing turns undersea cables into detectors for ships and seabed activity
- Operators would have to give government six months’ notice of new deployments
- Government could impose conditions on deployments or ban them outright
- Operators would have to share sensing data with government on request
- Consultation closes on 14 January 2027
Cable operators would have to hand over undersea sensing data to the UK government when asked.
The Department for Digital, Culture, Media and Sport and the Department for Energy Security and Net Zero set out the plans in a white paper published on Thursday (22 October).
Fibre-optic sensing uses the glass fibres inside subsea cables to detect vibrations and temperature changes along their length. The technology can pick up passing vessels, seismic activity, anchor drags and disturbances on the seabed.
The technologies in scope include:
- Distributed Acoustic Sensing (DAS), which detects vibrations and acoustic signals along the cable
- Distributed Temperature Sensing (DTS), which measures temperature changes along the cable
- Optical interferometry, which tracks changes in light to detect movement or strain
- State of Polarisation (SoP) sensing, which analyses how light changes as it travels through the fibre
The government said sensing data could compromise UK defence interests if a hostile state gained access to it. It added that the technology gives operators early warning of cable damage and supports earthquake monitoring and marine research.
Six months’ notice
The company that controls the fibre would have to notify government at least six months before a permanent deployment on an existing cable.
Operators building new cables with built-in sensing would have to notify government at the planning stage, typically at least 12 months before installation.
Operators already running sensing technology would have 90 days to notify government once the law takes effect.
Notifications would include who owns the cable, who operates the sensors, which third parties can access the data, and the location of the interrogator units.
An interrogator unit is the equipment, usually at a cable landing station, that sends light pulses down the fibre and reads the returning signals.
For urgent uses such as finding a cable fault, operators could file a provisional notice in advance and switch sensing on with 72 hours’ notice.
Operators would not have to wait for the government’s review to finish, which could take up to six months, before switching sensing on.
The government could issue an interim order blocking a deployment where it sees an imminent threat to national security.
Conditions and outright bans
The government would review each deployment based on the operator’s identity and any links to hostile actors, the technology’s capabilities, and its location.
It could impose conditions on how operators configure and run the technology, and in rare cases ban a deployment outright.
Every operator would also have to meet baseline security requirements, including complying with government requests for sensing data.
The government said regulations could require operators to share data in the form and at the frequency it requests.
Other possible requirements include:
- Encrypting sensing data in storage and in transit
- Keeping sensing systems separate from corporate IT
- Controls on where operators store data, including in the cloud
- Restricting access to vetted staff and sharing a list of those staff with government
- Housing sensing equipment in a locked cage or secure room with CCTV and alarms
The rules would cover sensing on cables that connect to the UK where the technology can detect activity in UK waters, including the exclusive economic zone that stretches 200 nautical miles from the coast.
They would also cover cables that pass through UK waters without landing in the UK, because these could equally reveal UK military activity.
Standalone seabed sensors and buoys would fall outside the rules, as would sensing used only to monitor a cable’s own condition.
Breaches would carry fines based on a percentage of annual turnover, with daily penalties for continuing breaches.
The government is also considering criminal penalties for deliberate breaches that endanger national security.
The proposals form part of a wider package that includes jail terms of up to 14 years for deliberately damaging undersea cables.
