The pros and cons of quantum networking

What is quantum networking?

A quantum network directly relates to quantum physics and communication. Its physical infrastructure comprises multiple quantum processors that exchange information in the form of qubits. Quantum networking is the process of transmitting and receiving information encoded in states of qubits within a quantum network.

The principles of quantum physics govern quantum networking protocols, and algorithms exchange information with high levels of encryption between multiple nodes that are distributed across vast distances. These principles initiate quantum networking protocols to provide fast, reliable and secure communication.

Because quantum networking is such a new networking technology, it can be a challenge for providers to commercialize it. This article discusses some pros and cons of quantum networking and the challenges related to its implementation.

Benefits of quantum networking

Although still nascent, quantum networking has the potential to offer several next-generation advantages. Benefits of quantum networking include the following:

• Wide variety of applications.
• Shared problem-solving.
• Long-distance communication.
• Reliable transmission.
• Enhanced security.
• Quantum cryptography.
• Error detection and correction.

Wide variety of applications

In quantum networking, the network sends and receives information in qubits, often called logical qubits. The entangled, or superpositioned, states of the qubits encode the information. These qubits exist in multiple states -- 0, 1 or both -- at the same time but change at the time of measurement due to wave-function collapse.

Photon energy drives most quantum networking technologies. The dual-particle and wavelike nature provide a variety of quantum-related applications, like quantum sensing, quantum teleportation, quantum simulation and more.

Shared problem-solving

Ideally, a certain number of quantum networks can deploy multiple nodes to fix a shared problem. Quantum networking requires high computational power and speed to compute complex problems.

For example, distributed quantum computing is a quantum network cluster in which multiple quantum processors connect to fix complex problems and perform high-speed computing together. Quantum networking infrastructure can also connect to the quantum internet to form quantum IoT with quantum processors, sensors, repeaters, controllers and other devices.

Long-distance communication

Quantum entanglement describes the transmission of qubits over long distances. In quantum networking, two or more qubits are in a state of entanglement with the same or opposite spins. These qubits first intertwine but then separate over large distances.

If the state of one qubit changes upon measurement, the other qubit changes automatically. Quantum entanglement is sometimes called quantum teleportation, as the actual qubits don't transfer over the channel to the router and other networking devices.

Reliable transmission

The TCP/IP model describes the transmission of data packets over a network and an acknowledgment from the receiver. Quantum networking eliminates the need for acknowledgment because it's possible to predict the intertwined states.

Quantum repeaters deploy at a single or multiple locations to enhance the reliability, computing power and range of quantum networks. In other words, quantum repeaters reduce the effects of decoherence and signal loss to provide accurate information.

Enhanced security

The no-cloning theorem states it's impossible to reproduce the quantum information of an unknown state onto another. A hacker, known as an eavesdropper, can't create a perfectly independent and identical copy of the unknown entangled quantum state.

However, a hacker can try to manipulate qubits in a quantum network to obtain a certain degree of replication. Quantum networking protocols can detect the manipulation on the channel and offer quantum error detection and correction capabilities to ensure high levels of security.

Quantum cryptography

Quantum networking incorporates quantum cryptography to cipher and decipher information. Quantum key distribution (QKD) is a quantum cryptographic protocol that enables secret key sharing in the form of qubits, or polarized photons, over an insecure network.

In quantum cryptography, Heisenberg's uncertainty principle states it's impossible to measure the speed and position of a particle at the same time for an ultrasecure connection. The sender and receiver compare the measurements to eliminate the error, detect third-party attempts and decrypt the secret key. QKD protocols include BB84, decoy-based QKD and more.

Error detection and correction

Quantum networking can help attain high accuracy with quantum error detection and correction algorithms. Many error correction algorithms detect deviations in the received qubit state from the transmitted photons.

These protocols enable users to find out possible hacking attempts made to the quantum network. Some of the error correction codes are Shor, bosonic and bit flip.

Challenges of quantum networking

Despite the several benefits of quantum networking, it isn't without challenges. Disadvantages of quantum networking include the following:

• Fragile nature of quantum information.
• Complex manipulation.
• Slow communication.
• Scalability issues.
• High costs.
• Complex integrations.

Fragile nature of quantum information

Quantum information is fragile in nature, which makes it susceptible to environmental factors, like quantum interference, decoherence and signal loss. Network professionals can deploy quantum repeaters at multiple segments as a way to maintain the accuracy of quantum networking. In addition, quantum operators need to operate on the qubits during error correction procedures.

Complex manipulation

From an enterprise perspective, the inability to copy the quantum state might limit many applications on a routine basis. In these cases, quantum logic gates manipulate quantum information between nodes to enable transmission. However, quantum logic gates can't violate the no-cloning theorem.

Slow communication

A common misconception is that quantum communication is faster than the speed of light. However, quantum networking often uses conventional communication methods to eliminate the possibility of faster-than-the-speed-of-light communication. Quantum networking uses optical fiber for communication, like the traditional internet.

Scalability issues

Long-distance quantum communication is currently hypothetical because a quantum network with many nodes uses short distances to separate them. Quantum networks typically have fewer processors than classical networks. Quantum processors can practically generate fewer superpositioned or entangled qubits in quantum networking protocols.

High costs

The implementation and maintenance of quantum networking require a high-cost investment. Quantum networking hardware and software need high investments in technology, engineering and costs. High-budget industries, like government, deep-space research and cryptographic projects, better suit quantum networking.

Complex integration

Quantum networking has its own standardization and interoperability required for hybrid networks. To integrate with the classical internet, a network must deploy a large number of quantum processors. Moreover, the TCP/IP communication model and quantum networking work on different technologies, and it's difficult to combine them.

The future of quantum networking

Large-scale enterprises and organizations are interested in quantum networking to enable optimized computing and fast communication and address complex problems.

It will take years for quantum networks to operate commercially at affordable prices like current computer networks. In the next few decades, several sectors like IT, space, research, healthcare and retail can attain fast communication and high-performance computing with quantum networking.