QNu Labs quantum security passes fibre network test

QNu Labs has validated its ARMOS quantum key distribution platform in an independent study with VIAVI Solutions, which tested the system's performance on standard telecom fibre networks.

Using VIAVI's MAP-300 test platform, the assessment examined how ARMOS performs under conditions intended to reflect deployment in enterprise and critical infrastructure networks. The findings showed that the system generated secure keys over distances of up to 200km on standard fibre with 40 dB loss and no signal amplification, while keeping Quantum Bit Error Rates below 4 per cent.

At shorter metro-scale distances of about 50km, ARMOS delivered secure key generation rates of up to 8,000 secure bits a second. At 200km, that rate fell to about 200 secure bits a second, but the platform continued to operate reliably across different network conditions.

A central result was the platform's ability to run alongside 10 Gbps classical data traffic on the same fibre without measurable degradation to the quantum channel. That matters because coexistence with conventional network traffic has been one of the main practical hurdles to wider use of quantum key distribution in live telecom environments.

The report also found that the system detected and recovered from simulated fibre cuts within minutes without manual intervention. It maintained secure key generation during tests involving attenuation and polarisation fluctuations, which the study described as signs of operational resilience under real-world conditions.

Protocol design

QNu Labs attributed much of the performance to its decoy-state Differential Phase Shift protocol, which it said allows the system to tolerate up to 40 dB of channel loss and extend transmission range beyond that of conventional quantum key distribution systems.

Quantum key distribution is designed to let parties exchange encryption keys using quantum mechanics, with the aim of detecting interception attempts. Interest in the technology has grown as governments, telecom operators, and security vendors prepare for a period in which quantum computing could weaken some widely used cryptographic methods.

For operators and large organisations, a key question has been whether such systems can be added to existing fibre infrastructure without major redesign or reduced performance for conventional traffic. The QNu-VIAVI study sought to address that directly by measuring operation on shared fibre carrying high-speed data.

"As the industry moves closer to a quantum-driven reality, the need for proven, deployment-ready security solutions becomes critical. This validation reflects the depth of engineering and real-world readiness we have built at QNu Labs, with VIAVI's globally recognised testing environment further reinforcing the robustness of our approach. It demonstrates that quantum-safe communication can be implemented at scale, without compromising on performance or disrupting the existing network architectures," said Sunil Gupta, co-founder and chief executive officer of QNu Labs.

VIAVI presented the work as part of a broader push to test quantum security systems under telecom conditions rather than only in laboratory settings.

"VIAVI brings deep expertise in optical, photonics, security, and critical systems testing to accelerate quantum-safe communications into real-world networks. We deliver independent validation with uncompromising rigor so these technologies perform at scale under real telecom conditions. We're proud to partner with QNu Labs to validate the ARMOS QKD platform, a key step toward operational, quantum-resilient infrastructure," said Yamany.

Market context

QNu Labs was incubated at IIT Madras and focuses on quantum-safe cybersecurity products. According to the company, ARMOS has already been deployed globally, while its US-based spin-off enQase serves the American market as a separate entity.

The latest study places the Bengaluru- and Delhi-based firm in a field where vendors are trying to show that quantum key distribution can move beyond pilot projects into practical use for banks, telecom groups, utilities, and government networks. In that market, proof of stable performance over long distances and shared infrastructure is likely to carry more weight than theoretical claims alone.

QNu Labs also used the study to argue for a larger role for Indian-developed cybersecurity technologies in the global market.

"Quantum security is at an inflection point where intent needs to translate into informed adoption. What this study enables is a shift from abstract promise to demonstrable capability, giving stakeholders the confidence to engage with quantum-safe technologies more decisively. For us, it is equally about shaping how these conversations evolve globally, positioning India-built sovereign indigenous innovation like QNu's at the forefront of credible, scalable cybersecurity solutions," said Sudiptaa Paul Choudhury, chief marketing officer of QNu Labs.