QNu Labs

What it Takes to Build the Best Quantum Networks

What it Takes to Build the Best Quantum Networks

MARCH 14, 2024 | QNu Labs


Quantum technology has been the most revolutionary phenomenon of the 21st century. Quantum computing hogs the limelight for its immense processing power and the ability to transform many areas of our technological life. It also has the potential to tackle some of our most pressing global issues, from climate change to food security.

Another important quantum technology in the offing is quantum communications. It connects systems and transmits data securely among them using principles of quantum mechanics. Quantum communications security will replace the current classical counterparts although the classical networking components will remain the foundation of this technology. Quantum security will extend the existing networks to enable the secured exchange of data/information between today’s classical endpoints and applications to the workloads in the cloud, and data centres enabling various stakeholders to connect to resources from wherever they are. The beauty of this technology is that it is future-safe – meaning even the best of the quantum computers will not be able to compromise the data security of current communications networks.

How Quantum Networks Work?

At the heart of quantum networks lies quantum communication technology that involves sending and receiving quantum mechanics-induced information to secure data. The process of securing network information is dependent on the medium of use – for example on terrestrial fibre networks quantum superposition is leveraged while on ethernet or wireless communications security quantum-resistant cryptography is leveraged. This renders utmost confidentiality and privacy of communications between the sender and the receiver without having to worry about the presence of any eavesdropper on the communications path.

Quantum Networking could be implemented in three stages.

  • Point-to-Point The initial stage of quantum network development will be defined by establishing secured communications between two separate locations.
  • Many-to-One: As there are limitations to scaling point-to-point connections both from a cost and technology perspective, the next stage of quantum networking will be defined by technology that enables multi-point network connectivity.
  • Quantum Internet: The final stage would be characterised by technology that enables a “network layer” for reliable any-distance, any-network type quantum communications through a complex web of nodes across the network, which relies on resilient quantum hardware or software at each location.

Once a quantum transmission link is established, the communications channel is intrinsically secure. It can’t be intercepted or copied without corrupting the data. Quantum networking is, therefore, attractive in any use case requiring completely secure networking, within a data centre, across a campus, on a metro area network, or a WAN.

QKD in Quantum Networks

A huge amount of investment and research has gone into the problem of how to create quantum-safe networks. Quantum Key Distribution (QKD) has proven to be an exciting field in this space.

QKD technology takes advantage of the laws of quantum physics to ensure that bad actors cannot decrypt data in transit even with the use of powerful new quantum computers, while still maintaining security against other high-performance computers.

For telecom providers, QKD technology offers a way to protect customers from current and future cyber security threats. However, integrating QKD into existing networks has traditionally presented complications, including the need to introduce dedicated dark fibre cables alongside the original infrastructure to carry the quantum signal.

But, there’s a solution.

Multiplexing: An opportunity 

Wavelength division multiplexing (WDM) is a common technique used in fibre optic networks that involves placing many different optical data wavelength channels on the same fibre, greatly increasing the fibre’s data-carrying capacity.

WDM, or simply ‘multiplexing’, is the simplest solution to integrating QKD onto telecom providers’ existing fibre, with the secret encryption keys transmitted on the fibres that are already carrying conventional telecoms data services.

An alternative approach is the use of post-quantum cryptography in conjunction with QKD. While QKD over dedicated fibres has been available for some time, this hybrid innovation makes the creation of quantum networks economically viable for the first time. Using this approach, it’s possible to easily implement quantum security on an existing network infrastructure, without the need to introduce significant additional costs —radically reducing the TCO of making a current infrastructure quantum-safe.

The Path Forward

True quantum networks are being embraced by data-sensitive organisations like defence networks, government networks, critical infrastructure, and the like today but the day is not far when enterprises will embrace them directly or through their telecom service providers, cloud providers, etc.  The holy grail is considered to be the quantum internet where technology becomes pervasive everywhere on devices, networks, and applications.

If your organisation is thinking about forward security and confidentiality of data for the long haul, do reach out to us for a free consultation – our experts will work with you to define ‘how’ and ‘where’ to start implementing quantum security that has the highest benefit and impact for your organisation.