Network security
QED-C assesses six applications: QKD, blind quantum computing, quantum-secure direct communication, quantum position verification, quantum secret sharing and quantum digital signatures.
QKD nearer; others mixedPost-Digital Primer 11
Quantum networks
Quantum networking is not one market or one timeline. Security, distributed computing and sensing need different network performance, components and commercial models.
Why it matters
A useful quantum network must do more than carry a delicate optical signal between two laboratories. It must connect quantum computers, sensors or other quantum nodes with sufficient fidelity, synchronisation, transmission rate, distance, scale and connectivity for a specific application. This creates potential roles for fibre and satellite operators, network vendors and specialist integrators, but those roles vary sharply by use case.
QED-C Quantum Networking Applications Roadmap ↗What it is
A quantum network connects quantum nodes and distributes quantum information, including quantum states or entanglement. Endpoints may be quantum computers, sensors, memories or security devices. Fibre, free-space optical links and satellites can carry photons, while light sources, detectors, light-matter interfaces, frequency converters, memories, repeaters and quantum-compatible switches form the wider system. Conventional networks remain essential for coordination, control, timing, management and application data.
What it is not
A quantum network is not the same as post-quantum cryptography, which runs on ordinary computers and networks. It is also more than a QKD link, and entanglement does not permit faster-than-light communication. A distance record does not demonstrate a useful network if fidelity, availability, switching, synchronisation or endpoint readiness remain inadequate. The phrase 'quantum internet' can therefore conceal several distinct systems with different buyers, economics and timescales.
Telecoms read-acrossThe QED-C roadmap provides a useful systems view because it maps ten applications to seven performance metrics and the components each requires. Nearer-term operator roles are most plausible in QKD, managed optical transport and metro testbeds. Clustered quantum computing may remain an internal datacentre interconnect controlled by quantum vendors or hyperscalers. Longer-distance connectivity could eventually create opportunities around qualified fibre and satellite paths, quantum-compatible switching, precise timing, orchestration and assurance, but fibre ownership alone will not be enough.
How it works
01Create and interface
Quantum light sources and light-matter interfaces generate photons or connect stationary qubits in computers, sensors and memories to a transmissible optical state.
02Transmit
Fibre or free-space optical paths carry the quantum state. Frequency conversion may be needed to match an endpoint to the wavelength best suited to the network.
03Switch and extend
Quantum-compatible optical switches select paths. Future repeaters, memories and satellite links may extend distance without measuring and recreating an unknown quantum state.
04Synchronise and assure
Classical control systems coordinate nodes, timing and recovery while operators monitor fidelity, qubit rate, distance, node count, network size and connectivity.
Use cases
Potential uses.
Status labels show use-case maturity.
Clustered quantum computing
Connect processors within a datacentre or campus so several quantum systems can work on a larger task. QED-C estimates a horizon of roughly five years, but this may remain a proprietary datacentre fabric.
QED-C estimate: about 5 yearsLong-distance distributed computing
Connect quantum computers across separate facilities. The roadmap finds large gaps in performance and enabling technology and places this at about ten years.
QED-C estimate: about 10 yearsNetworked sensing
QED-C assesses quantum-enhanced time synchronisation and distributed quantum sensing. Limited point-to-point sensing links are possible today, although sensor readiness may be the main bottleneck.
Research and specialist trialsTelecom relevance
Possible telecom roles.
Fibre operators
Qualify routes for wavelength, loss, drift, maintenance events and coexistence, then expose more than undifferentiated dark fibre or capacity.
Satellite and free-space providers
Explore very-long-distance and hard-to-reach segments while accounting for weather, pointing, background light, ground stations and trust boundaries.
Network and OSS vendors
Develop quantum-compatible switching, inventory, orchestration, synchronisation, assurance, fault diagnosis and recovery across mixed media.
Research and wholesale teams
Use metro testbeds and managed optical transport to learn where repeatable services and customer demand exist before promising a general quantum network.
Reality check
Pre-requisites and proof-points needed
These questions test whether the technology can become a practical, supportable system.
- 01Which of the ten applications is the network intended to support?
- 02Which required metric or component has actually improved?
- 03Can the system recover from rerouting, repairs, connector changes, drift and adjacent-channel loading?
- 04Are endpoint readiness, operating cost and a credible paying customer included in the claim?
Related signal coverageSignals 041, 045 and 047–049
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