# Blind Computing and Quantum Networks – Towards a Quantum Internet

In the search for new ways to increase the speed and quality of content transfer (there will be a webinar on this soon, join us), sooner or later the question arises: is it possible to transfer data instantly and securely, regardless of distance? Our ideas about how to exchange information on the Internet may soon be changed by a quantum network.

Quantum communications are becoming more accessible, not least thanks to cloud computing. The cloud allows researchers and companies to experiment with quantum algorithms without having to own expensive hardware.

It is safe to say that full-fledged quantum machines will continue to work with virtual infrastructure. To ensure their operation, engineers have already developed protocols that protect data and ensure its privacy when processed by a quantum computer in the cloud.

We can already roughly imagine the future *quantum internet*.

## Quantum Clouds

The concept of quantum computing was proposed in the early 1980s by physicist Paul Benioff, who in one of his articles described a quantum mechanical model of a Turing machine.

But the first significant breakthrough in quantum computing didn't come until 1994, when Peter Shor, a mathematician at Bell Labs, introduced a quantum algorithm for multiplying large numbers that was many times faster than classical approaches.

The early 2000s saw another round of development in quantum systems: Shor, together with his colleague Raymond Laflamme, developed quantum error correction codes to make calculations more reliable and resistant to external interference.

As a result, Shor and his colleagues were able to show that *Quantum computers may be able to outperform classical computing systems*.

Later, theoretical physicist John Preskill even coined a special term – “quantum supremacy”. Today, among representatives of the scientific and IT community, one can find the opinion that it has already been achieved. Back in 2019, the 53-qubit quantum computer Sycamore performed calculations according to an experimental algorithm in 200 seconds, while the IBM Summit supercomputer would have needed 10,000 years to do so.

At the same time, a number of experts note that it is premature to talk about achieving quantum supremacy, and a fully functional quantum machine, according to the most optimistic estimates, will not appear earlier than in ten years.

The results of past and current experiments can be interpreted in different ways. For example, IBM engineers found an error in Google's calculations and proved that the company's supercomputer can cope with the task in just 2-3 days, and with greater accuracy.

That is why experts increasingly talk not about “quantum supremacy,” but about “quantum advantage”: an approach in which technology will not replace classical systems, but *will complement* their.

Experts disagree on when fully functional quantum computers will appear, but a significant number of them are confident that such systems will generally work *from the cloud*The fact is that their operation requires special conditions.

A data center is the perfect place for IT equipment. It doesn’t matter whether it’s a quantum computer from the future or a regular five-kilowatt customer rack. A good data center provides stable temperature and humidity levels, multi-layered backup power systems using UPS and diesel generators, and security measures that prevent, for example, the construction of a highway through the building.

In this context, remote connection to a computing system and renting its capacity seems like a logical step. And this is already happening – dozens of companies are experimenting with this format.

## Secure “blind computing”

Another factor that significantly influences the development of cloud quantum computing is security. You can request certificates of compliance with international standards from a regular data center, such as Tier III. You can also use a VPN channel and connect cloud cybersecurity services, from antivirus to web application protection.

To solve this problem for quantum computers, researchers have proposed several protocols. For example, a protocol for conducting “blind quantum computations” based on coupled ions. The concept of this type of computation implies that the server performs them without having full information about the tasks being solved and the data being processed.

Similar systems and algorithms have been worked on in this area for a long time, but previous approaches had shortcomings related to the accuracy of calculations, and engineers faced the problem of building interfaces for exchanging data in a pair of “classical computer – quantum computer”.

The classic approach involves working with photonic qubits. However, the operation of such systems is largely probabilistic in nature. Oxford specialists used qubits consisting of electrically charged atoms, or ions. A strontium ion played the role of a “network qubit” that sends photons to the client. A calcium ion was called a “memory qubit” because it stores information that can be used in subsequent iterations of the protocol. Photons are exchanged via a fiber optic cable. Confidentiality is achieved through polarization and data encryption.

Despite the great potential of “blind quantum computing”, the protocol still requires improvement. Thus, to perform complex calculations, it is necessary to increase the number of qubits, which is technically difficult, although proposals for creating such systems already exist. Therefore, the likelihood of improving the approach is high.

## Transition to a Quantum Internet

cOne of the main requirements for a data center is connectivity. Both with global traffic exchange points and with other data centers. For example, in MWS, in order to synchronously replicate disk arrays, data centers in one region can be located at a distance of 10 to 70 km from each other. Thanks to the configured connectivity, at least one independent copy of the data is always available.

In the “quantum” context, technologies are being developed to bring the emergence of a quantum internet closer. In 2022, engineers managed to establish quantum entanglement at a distance of 12.5 kilometers. The ability to maintain quantum entanglement in urban conditions is an important step in the development of quantum networks and distributed quantum systems.

*Quantum entanglement is a phenomenon in quantum mechanics where two particles are linked. When one changes state, the other changes state as well. This property plays a key role in quantum computing: entanglement of qubits allows for greater parallelism when working with data, so quantum computers can solve some problems faster than classical systems.*

In June 2023, an international team of researchers succeeded *combine two quantum memory devices* based on diamond into the network. In its crystal lattice, two carbon atoms were replaced by one silicon atom. The resulting “defect” allowed the particles to entangle and maintain their quantum state for one second. Importantly, the experiment was conducted outside the laboratory using a fiber-optic channel more than 35 kilometers long.

Another experiment with quantum memory was conducted by researchers from the Spanish Institute of Photonics. They managed to create and maintain entanglement between two memory devices located 10 meters apart. To do this, they used multiplexing, a technology that allows several messages to be transmitted simultaneously over a single communication channel. As a result, they managed to maintain a superposition state for 25 microseconds.

In addition, work is already underway to integrate quantum machines into existing infrastructure. In November 2023, Microsoft and Photonic were able to transmit information between two qubits at a communication wavelength. This experiment demonstrated that **existing networks can be used to build a quantum internet**.

Also recently, specialists have developed a new method for forming quantum light emitters (color centers) in silicon. A color center is a defect in the structure of a solid substance that, by absorbing visible light, infrared or ultraviolet radiation, allows the generation of polarized single photons suitable for data transmission.

Typically, defects are created by continuously irradiating a material with a stream of ions. But scientists have found that pulsed ion beams are much more effective. The results of the experiment could lay the foundation for a quantum internet, as they will provide a deeper understanding of the properties of quantum emitters.

## What else to read on the topic

While scientists are working on the fundamental aspects of quantum machines and networks, it is quite possible to prepare for the onset *quantum future*To get a better understanding of quantum computing, you can start with these books.

A new book by theoretical physicist, futurologist and popularizer of science Michio Kaku. The scientist is known for explaining complex scientific topics in simple terms. In addition, Michio Kaku is one of the co-authors of string theory. In his new work, he explores the potential of quantum computers in solving human problems. Among them are hunger, incurable diseases and others. The author also considers the impact of quantum computing on cryptography and data security. He assesses the risks associated with the fading of classical computer systems into the background and analyzes the technological gap between countries.

“Dancing with Qubits: How Quantum Computing Really Works”

A book by Robert Sator, one of the developers of IBM Q. The author methodically reveals complex topics to readers: from the basics of quantum mechanics to the operation of a quantum computer. He does not simply offer theoretical reasoning, but gives examples of the use of quantum computing in the field of cryptography, modeling, and the development of new materials. “Dance with Qubits” is a good guide to the world of quantum technologies in Russian.

“Quantum in Pictures: A New Way to Understand the Quantum World”

The book offers a new approach to studying quantum mechanics using visualizations. The authors use the graphical language ZX-calculus to explain key concepts of quantum physics such as entanglement, teleportation, and quantum uncertainty. This method of presenting the material allows for the avoidance of complex mathematical terms and makes the most intricate topics accessible.