In October 2026, Rajiv Shah presented at the Connectivity Innovation Network’s Beyond 5G Summit in Sydney on the role of quantum technology in 6G mobile networks.

The question behind the talk was simple: of all the quantum technologies being promoted to the telecommunications industry, which will actually matter for 6G?

Why this matters now

3GPP is set to publish the first 6G specifications in early 2029, and commercial networks are expected around 2030. Those networks, along with the devices, SIMs and infrastructure connected to them, will still be in service in the 2040s. So decisions taken on 6G today have to hold up against whatever quantum technology delivers over the next 20 years.

Quantum communication: a niche, not a network

Quantum communication and networking have been promoted with some striking promises: unbreakable encryption, ultra-fast transmission and even teleportation. The physics is real. The engineering reality is very different.

Quantum key distribution (QKD) only protects data under tightly caveated assumptions, including near-perfect hardware and a separately authenticated classical channel. Photons are lost over distance, so practical links need trusted relays roughly every 100 km, and each relay sees the key in the clear. And there is no credible path to running QKD over the radio link to a mobile handset, which is where 6G actually lives.

Security agencies agree. The NSA, the UK NCSC, the Australian Signals Directorate and a joint group of French, German, Dutch and Swedish agencies have all declined to support QKD for general secure communications. Some niche, fixed-link uses may remain. QKD is not a 6G technology.

Quantum computing: not fast enough to run the network

6G will depend on complex optimisation and scheduling. Quantum computers may eventually help with some of these problems, possibly within the 2030–2040 period when 6G networks peak. But they will be large, expensive and slow to access, and radio networks make decisions in milliseconds. Real-time network management will still rely on conventional AI and GPUs. Any quantum role is more likely to be in offline planning and resource allocation.

Quantum random numbers: good physics, not the real problem

Quantum random number generators produce high-quality randomness, and some handsets already ship with them. But the real-world failures in cryptographic key generation have been implementation failures: poor seeding, buggy software and weak device design. A better source of randomness doesn’t fix those.

Quantum sensing and timing: genuine value

The most practical quantum technology for operators may be the least glamorous. Mobile networks depend on precise timing, and most of that timing comes from GPS and other satellite navigation systems, which can be jammed and spoofed. Quantum clocks and sensors could keep time and position accurate when GPS is unavailable. Their output is a conventional timing signal, so they fit into existing synchronisation systems without changing the network itself.

The real issue: post-quantum cryptography

The biggest quantum issue for 6G doesn’t need anything quantum in the network.

A sufficiently capable quantum computer would break the public-key cryptography that mobile networks rely on today, including the cryptography that protects subscriber identities, secures links across the core and backhaul, and underpins certificates and firmware signing. No such machine exists yet, but one becoming feasible somewhere between 2030 and 2040 is a credible prospect. Data recorded today could be decrypted then.

The answer is post-quantum cryptography (PQC): new mathematics, running on existing classical hardware, designed to resist quantum attack. NIST published the first PQC standards in 2024, and 3GPP, the IETF and the GSMA are working through what they mean for mobile networks. The hard part is the long chain from algorithm to deployed network: larger keys and signatures, constrained IoT devices, legacy and roaming interoperability, and the slow work of replacing certificate infrastructure.

What this means for 6G

As 6G standards and the protocols that run over them are developed, they should:

• use PQC by default
• be crypto-agile, so algorithms can be updated without redesigning the network
• integrate securely with legacy systems, and fail securely when they can’t

Meanwhile, migration of existing 5G networks needs to start now.