As quantum technology quickly moves into the real world—onto factory floors, into data centers and across other critical infrastructure—it’s reshaping expectations for how networks are built, how data moves and how problems are solved.
Because quantum computing can evaluate many possible solutions in parallel, it can resolve long-standing challenges that classical systems have struggled to solve efficiently, such as complex routing, scheduling and inventory optimization.
Progress on the quantum hardware side continues to accelerate, with an IBM quantum network solution on the horizon within the next few years, and Fujitsu targeting 2030 for its own system.
But with this progress also comes risk: The same advances that make quantum computers powerful optimizers threaten current encryption methods. In fact, by 2029, experts predict that quantum machines will likely be able to break widely used public‑key encryption schemes within minutes. (This milestone is dubbed Q-Day, marking the day when today’s cryptography will no longer be considered safe.)
Because bad actors will have access to quantum computers in the near future, networks will need to be able to withstand classical and quantum attacks.
Understanding what quantum can do—and how it changes networking and security—is essential to building quantum‑ready infrastructure that supports new capabilities without putting systems and data at risk.
Classical vs. quantum networking: How are they different?
To understand quantum and how it can unlock new possibilities, it helps to compare it to the classical networks in use today.
Classical Networking
Classical networking is the world you already know and interact with daily: It involves switches and routers moving data over copper and fiber, with protocols designed to keep traffic moving, even when the signal isn’t perfect (“good enough” is okay in many cases). As long as applications still receive the information they need in an acceptable amount of time, the network is performing. There’s no requirement to preserve the exact state of every signal.
Data in these environments is represented as bits. When these bits are distorted or lost due to noise or signal loss, the problem most often is fixed through error‑correction and/or retransmission.
Quantum Networking
Quantum systems store and process data in qubits encoded in extremely delicate states. Small perturbations can corrupt a quantum network, which is why its links must aim for maximum fidelity (very high quality).
This quality requirement allows quantum computers to tackle challenges that classical machines can’t. They leverage the principles of quantum mechanics to address complex problems involving a vast number of variables and conflicting constraints. Consider machine maintenance: Given possible repair times, repair technician availability and resource requirements, scheduling maintenance for even 80 machines can create too many possibilities for traditional computers to evaluate within a reasonable timeframe.
Design realities of quantum networking
The need for high‑quality qubits and clean transmission paths quickly turns conversations about quantum networking into discussions about what’s required to keep quantum information intact from one point in the network to another.
Here are a few examples of what quantum networking will require.
Designing low-loss links
Creating a physical network to support quantum interactions from computer to computer requires links with incredibly low loss and extremely high-quality optical characteristics.
Meeting these requirements often calls for more advanced fiber designs than those used in typical production networks. This can include new or specialized glass compositions, or structures such as hollow‑core fiber, which can both reduce loss and better preserve quantum information across long distances.
Giving quantum traffic its own lane
To keep performance predictable, quantum networking traffic needs its own path. To accomplish this, one option is to create a separate physical network for quantum traffic, similar to how you might dedicate a physical network to backup or storage traffic.
In this model, a server or system would have two network ports:
- One connected to the quantum network segment
- One connected to the production network that supports everyday operations
This approach lets you tune one network specifically for quantum traffic without having to redesign every part of the existing production network.
Extending the quantum path
Quantum networking happens between buildings or across a city, but it also happens inside quantum systems themselves. Between the outside world and the quantum processing unit (QPU) is a control stack that receives classical traffic, manages quantum operations and connects to the QPU over RF cables.
Inside the quantum computer, those RF links enter a refrigeration stack (a cryostat) where pressure drops to a near‑vacuum level and temperatures fall below those in outer space.
From there, the signal travels out of the cryostat, through the control stack and out to the fiber links that connect quantum systems. Along that path, everything has to be engineered to move quantum information reliably. This calls for cabling that can transition from standard, room-temperature RF designs to highly specialized designs that operate at extremely low temperatures and pressures.
Building a quantum-safe network
The same advances that will let quantum computers tackle optimization problems also put typical encryption methods at risk. This means you must rethink how networks are connected and how traffic is protected long before Q‑Day arrives.
In many operational environments, networking and control equipment stay in the field for a decade or longer. The devices you’re installing now will likely still be in service when quantum attacks take hold, which means the decisions you make today could affect how exposed you are to security risk in the future.
To help organizations adopt quantum-safe networks, the National Institute of Standards and Technology (NIST) finalized its first set of post‑quantum cryptography standards in 2024 and recommends broad adoption by 2030. The standards are meant to give you a path to protect data and connections when attackers have access to powerful quantum computers.
Post‑quantum cryptography (PQC) is the next generation of encryption for a quantum world. It refers to new families of public‑key algorithms designed so that a powerful quantum computer can’t break them significantly faster than a classical machine. This makes the algorithms resistant to the kinds of attacks that will eventually break today’s ciphers.
Moving toward quantum-safe networks means swapping out existing public‑key ciphers for quantum‑safe ones so your network is protected from classical and quantum attacks. Over time, you’ll need to understand where non‑quantum‑safe ciphers are used (in VPNs, TLS sessions, device certificates and management channels, for example) and develop a plan to migrate those uses to PQC in line with emerging standards and guidance.
That way, data captured and stored today won’t be decrypted by tomorrow’s quantum machines. Your network can continue to protect systems and information as quantum computing matures.
Preparing networks for a future with quantum
Quantum networking is opening up new ways to move, secure and use information so organizations can connect to what’s possible. The teams that begin exploring quantum networking and quantum security now will be well on their way toward connecting future quantum systems and protecting long‑lived data in the decades to come.
Belden is actively evaluating emerging quantum capabilities and how they’ll affect the networks and systems already in the field. We’re engaging with quantum exchanges around the world and collaborating with other knowledgeable organizations, while also driving internal initiatives to educate our teams and our customers on what it means to build quantum‑ready, quantum‑safe infrastructure.
By combining this work with our complete connection solutions, we’re ready to help customers build networks that can evolve as quantum technologies move into everyday operations.
Learn more about our recent partnership