Brazil tests quantum-secure communication over Recife fibre network

Researchers in Brazil have developed the Recife Quantum Network, a quantum key distribution system that uses inactive optical fibre already installed in the city’s urban infrastructure to test secure communications outside a laboratory setting.

The project, led by Professor Daniel Felinto at the Federal University of Pernambuco, connects university departments through dark fibre and uses quantum key distribution to protect information exchange.

Quantum key distribution relies on quantum properties that make interception detectable: any attempt to observe or copy the security key disrupts the quantum state, alerts the system and prevents secure key exchange.

The work has grown into a broader institutional effort through the Institute of Quantum Technologies, known as Quanta, based at the university’s ParqueTec. Researchers from the Federal Rural University of Pernambuco are also involved. The initiative received recognition through the 2025 Finep Innovation Award in the Northeast Region, in the research and development infrastructure category.

Initial tests over 7 kilometres have been completed, and the team now aims to expand the Recife quantum network to 40 kilometres with support from development institutions linked to Brazil’s Ministry of Science, Technology and Innovation. The project has also received support from the ministry through the National Education and Research Network and its Point of Presence in Pernambuco.

The initiative is presented as a step towards applying quantum key distribution-based secure communications to strategic cybersecurity needs, including defence and financial systems. Its use of existing telecommunications infrastructure is significant because it suggests that quantum-secure communication systems can be tested in urban environments without requiring entirely new fibre deployment.

Why does it matter?

Quantum key distribution is being explored as a way to protect sensitive communications against future threats, including advances in computing that could weaken current encryption methods. The Recife project is significant because it moves testing beyond laboratory conditions and into existing urban fibre infrastructure, which is a practical requirement for any wider deployment of quantum-secure networks.

For Brazil, the project also links cybersecurity with national research capacity, regional innovation and digital infrastructure development, showing how quantum technologies are beginning to move from academic experimentation towards applied communications security.

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