Quantum leap: quantum key distribution and the new world of cybersecurity

On 05-01-2023
Reading time : 6 minutes

Quantum physics has the potential to be the next great frontier in computing. Its properties would allow unprecedented speeds and promise new levels of data processing and encryption. However, it is a complicated area and not without security risks. What do you need to know?

Quantum computing is an emerging technology that harnesses quantum mechanics phenomena such as “superposition” and “entanglement” to solve problems that are too difficult for “classical” computers. Quantum entanglement is such a counter-intuitive phenomenon that even Albert Einstein called it “spooky action at a distance”.

One of the key areas of concern regarding quantum computing is data security and protection. While the power of quantum computing is considered the biggest threat to data security, it is also the future of cybersecurity. 

Today’s classical computers cannot crack encryption that uses very large prime number factorization, of around 300+ integers. However, malicious actors using quantum computing could compromise current encryption standards, making them ineffective. Quantum information technologies can help overcome this issue by enabling new types of advanced cryptography, delivering much stronger protection of data and assets. 

How does it work?

The mechanics of quantum computing mean that hacking existing security measures could be performed exponentially faster. At present, classical computers process information using bits that equate to ones or zeroes. Quantum computers utilize quantum bits, also known as qubits, which can be set to one or zero, or both one and zero simultaneously. Working with bits that can exist in two states at the same time, together with entanglement, enables much faster decryption. 

In today’s world, while quantum computing remains outside of the mainstream, malicious actors are already harvesting conventionally encrypted data with the intention of hacking it with quantum computers further down the line. 

In reality, quantum computers could break the cybersecurity we currently use for common practices in daily life. And that could present a much more dangerous threat to healthcare, financial services and other sensitive personal data. It could also make digital documents more vulnerable. In short, quantum computing could conceivably break all currently used encryption, including the RSA code using Peter W. Shor’s algorithm. 

Awareness and activity increasing

Governments and enterprises are increasingly prioritizing quantum computing to protect data. The White House earlier this year issued a national security memo that instructed federal agencies to prepare to move from current encryption algorithms to new “post-quantum cryptography” algorithms, starting in 2024. 

The European Union (EU) is taking quantum computing very seriously too. It plans to “consolidate and expand European scientific leadership and excellence in this research area, to kick-start a competitive European industry in quantum technologies and make Europe a dynamic and attractive region for innovative research, business and investments in this field.” 

The EU’s Quantum Flagship project covers four main themes, including quantum computing, quantum sensors, quantum modeling, and quantum communications. The EU has also shown its commitment to the technology with the Quantum Internet Alliance project, designed to build the world’s first prototype of a large-scale quantum network in Europe named EuroQCI. 

How does QKD enhance security?

And as things stand, only one technology can guarantee detection of all attempts at intrusion and hacking using quantum: the quantum key distribution (QKD). QKD is designed so that two parties exchange a private key at either end of an interaction. But they do this by transmitting millions of polarized light particles, photons, down a fiber optic from one end to the other. Each photon has a random quantum state, and collectively all the photons add up to a bit stream of ones and zeros. 

When the photons arrive at the desired destination, the receiver uses beam splitters to determine the polarization of each photon. Then the receiver tells the sender which beam splitter was used to assess each of the photons in the sequence they were sent, and the sender compares that data with the sequence of polarizers used to send the photons. 

This way, the sequence of generated bits becomes a unique optical key for encrypting data. QKD is a particularly secure communication method because it uses quantum physics, not mathematics, to encrypt data. In essence, the laws of quantum physics ensure that any intrusion attempt will be detected. 

“It’s worth remembering that, today, all cryptographic mechanisms are based on solving mathematical problems. But quantum computers will have computing capacities ten times greater than those today. This means much more robust encryption than we can have now. QKD will be a huge leap forward,” says Dr. Thomas Rivera, Research Project Manager at Orange, specializing in quantum communications.

The extremely high level of security offered by QKD could be of interest to companies in various industries that have to manage highly confidential information. It’s easy to see it being in demand in banking and other financial services, or for government communications in bodies like the police or the military. 

Some challenges yet to overcome

Quantum networks are already being trialed and tested, but only really at regional levels. Quantum networks that cover long distances are still a rarity currently for several reasons. 

First, the equipment needed to build a quantum network is very expensive. Second, existing network equipment like repeaters don’t work with quantum technologies. And third, qubits use a very weak signal that is highly sensitive to noise or other environmental changes. Trusted nodes are needed to increase the range of this technology. This approach has been used for long range QKD networks such as in China, Korea or in UK. For long distances, quantum communications using low earth orbit satellites to send encrypted messages to ground-based stations is a more viable option.

Orange leading the charge towards quantum

Orange is involved in several quantum test and research projects at national and European levels. Those projects cover issues like trying to find ways to reduce the price of specific quantum equipment, and ensuring we can reuse our existing network infrastructure for quantum. That means driving towards coexistence of photons that carry quantum information for QKD and data that transmit TV and video, on the same fibers. 

Orange is also committed to helping the EU make the pan-European quantum network a reality and is a contributor to other key initiatives. This includes the Continuous Variable Quantum communications (CiViQ) project, in which Orange is working with a range of quantum communications experts to define quantum cryptography solutions enabling ultra-secure encryption. 

Orange is also engaged in the Open European Quantum Key Distribution (OPENQKD) testbed project, which aims to build an infrastructure for testing and evaluating quantum cryptography solutions across Europe. We’re also working on the EuroQCI (Quantum Communication Infrastructure) program, designed to provide Europe with a quantum communications infrastructure for terrestrial and space use.

In France, Orange is actively involved in two major quantum projects. The Paris Region Quantum Communication Infrastructure (QCI) project, coordinated by Orange, has deployed a quantum communication network between Paris and key business and university areas around Paris, to test out secure communication solutions, including QKD. One of the aims of this project is to federate the Ile-de-France ecosystem of quantum communications in Paris, which includes start-ups, academic labs and large companies in the region. 

We are also working on the Quantum@UCA project, in partnership with the Université Côte d’Azur. This project began life in 2019 and works to test quantum cryptographic key exchange over a city network based on entanglement. Orange provided “dark fiber” for the exchange of qubits, plus we bring our expertise in cryptography to the project. 

The end goal for both these projects is to link both networks via satellite. “It’s a really exciting time,” says Dr. Rivera from Orange. “We are proud of the progress we have made already in quantum, with projects like the ParisRegionQCI and the Quantum@UCA. We are happy that all the partners in both those initiatives have become partners in a larger project, FranceQCI, which aims to deploy the French quantum network. These projects will help us drive towards QKD and a safer, more secure future.”

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