A new era of communication

This summer we had a trial run of what a global technology disaster would look like. Thousands of people were stranded at airports worldwide after an update failure affecting software made by US cybersecurity firm CrowdStrike caused global system failures and left many scratching their heads at what became known as ‘the blue screen of death’.

The global glitch sounded a note of caution across nations on our potential digital flaws. And it inevitably fuelled concerns about our readiness for something much worse than having your flight delayed by several hours. A day where bank details, medical records and national defence secrets would be exposed in a matter of seconds.

Experts call it Q-day – the moment when sophisticated quantum computers become powerful enough to break the encryption safeguarding most of the internet. And it could be coming sooner than you think.

“The consequences could be catastrophic. When the quantum computer comes, then you’re too late,” Elham Kashefi, chief scientist at the National Quantum Computing Centre, tells Holyrood.

Many modern encryption methods protecting our data from cyber criminals rely on factorisation, which is based on the assumption that breaking down large numbers into their prime factors is very complicated – a task that traditional computers would take an impractically long time to solve.

However, in 1984 mathematician Peter Shor unveiled an algorithm that could solve factorisation, sending shockwaves across the cyber world.

His method relies on what is known as quantum superposition, which is the ability of a qubit, quantum computers’ basic unit of information, to be in multiple states at once.  Unlike classical bits, which are either 0 or 1, qubits can be both 0 and 1 at the same time, allowing them to process multiple calculations simultaneously. Think of it as a spinning coin being both heads and tails at once.

This means that qubits could significantly speed up the process of finding the prime factors of a large number.

Now, more than 40 years later, scientists are edging close to developing a quantum computer that could run Shor’s algorithm. And, at a time when cybercrime costs the UK economy around £27bn per year, this cyber-quantum doomsday could bring a financial disaster for all. But experts in Scotland may have the answer.

Mathematician Peter Shor

It is a windy day when I head towards Heriot-Watt University, where the UK Government has focused its efforts to tackle the quantum-enhanced cyber challenge, and the blustery weather only adds to the sense of urgency.

Early last year, the UK Government placed quantum “at the core” of its mission to make the UK “the most innovative economy in the world”, with one of its key missions being to deploy “the world’s most advanced quantum network at scale, pioneering the future quantum internet” by 2035.

And, although there’s been a political shift since, Labour seems to be heading towards the same goal. In July, it announced a £100m fund to turbo-charge the quantum revolution, establishing five hubs across the UK, two of them based in Scotland, one of which is Heriot-Watt’s Integrated Quantum Networks Hub (IQN), where the quantum internet is being developed.

I am welcomed by Professor Gerald Buller, who leads the research team. “There’s a lot to be done. We can’t wait to jump on the bandwagon,” he says.

Buller guides me through the maze-like corridors and never-ending stairs until we reach a door with “CAUTION” in bold red pasted on it. The dimly lit room is crowded in an organised mess of cables and futuristic machinery and as I step in it feels like I’ve teleported myself inside Doctor Who’s Tardis.

By exploiting the processes of quantum entanglement and quantum key distribution (QKD), the quantum internet hopes to deliver a future where cybersecurity is rendered near-obsolete.

Entanglement links qubits so the state of one instantly influences the state of the other, regardless of the distance between them, and QKD uses this to securely share encryption keys between two parties.

Qubits operate in superposition as long as they are not measured. Once this happens, they become either a 0 or a 1. So, if you look at the coin it becomes either heads or tails. This means that entanglement and QKD allow for any eavesdropping to be detected, as it would make the qubits adopt a definite state, revealing the encryption key has been compromised.

However, to date, the opportunity to scale up this network has been “very limited”, Alessandro Fedrizzi, co-director of the hub explains.

“The main barrier is that these individual photons (the particle used to transmit quantum information) that we send tend to get lost in the fibre because fibre is not completely transparent.”

Maintaining the quantum state of photons over long distances is complicated as environmental factors can make them lose their quantum properties. Currently, the largest quantum communications network is based in China and spans over 2,680 miles.

Fedrizzi continues: “That means that the distance an encryption key can be established over with a stream of photons is very limited. A true quantum network would have at all these intermediate nodes quantum repeater stations that would provide a quantum method to refresh the signal, which is what today in the classical internet happens all the time with amplifiers.”

However, the IQN team is determined to tackle this challenge. One of the technologies looked into at Heriot-Watt is quantum memories, which would store information in its quantum states until required; a “critical requirement” to transfer it over long distances, Buller tells Holyrood.

The team will also examine the connection of quantum communications to a low-earth orbit satellite. Currently, 500 metres from where I stand, researchers are building an optical ground station, via which experts hope the UK will eventually share quantum information with the US, Canada and Singapore.

Interestingly, no one can pinpoint when the supercomputer able to run Shor’s algorithm will come. “Nobody knows if it is going to be five years, 10 years or 20 years”, says Kashefi. But countries have already fired the gun and concerns of potential supremacy by hostile nations are unmistakable. In 2020 the National Cyber Security Centre (NCSC) said: “The possibility of one is a relevant threat now to organisations that need to provide long-term cryptographic protection of data.”

China, which has been accused of posing a cyber threat to the UK after targeting a group of MPs earlier this year, is currently ahead of the pack. In 2020 it reported it had achieved “quantum supremacy” after it developed a quantum computer, named Jiuzhang, that conducted a calculation, that would take a regular supercomputer around 2.5 billion years to complete, in 200 seconds. A discovery that highlighted the urgent need for adopting quantum-safe technologies.

“If other nations develop a scalable quantum computer before we do they will presumably find it easier to break public key encryption,” Buller says. “That’s one scenario. The other is, of course, if someone else develops an effective quantum network, they can connect quantum computers more easily. That gives them even more power. And they would also have a completely secure network, which we wouldn’t necessarily have.   

“There are of course a number of countries in the world that have huge research programs in this. Some are friendlier than others. And it’s difficult to know about the progress in some countries because they may not be as transparent as we are.”

Although the quantum internet is still in its early stages, the NCSC follows recommendations from the National Institute of Standards and Technology (NIST) in the US, which champions post-quantum cryptography to defend against potential quantum attacks.

While this approach does not provide the same level of future-proof security, experts are concerned that the ambiguity on Q-day is leading to businesses neglecting necessary guardrails.

“We have lots of options on the table. And all we are saying is, you cannot ignore it anymore,” Kashefi warns.

“You cannot say, ‘I don’t care about all this quantum’. You need to start the migration, either going with post-quantum or quantum communication or quantum internet.

“And migrating to a post-quantum secure world takes time.”

Laura Foster, head of technology and innovation at TechUK, echoes her concerns, calling for the government to do more: “If we’re thinking about quantum, we need to be thinking about how the commercialisation of these technologies will eventually look like. And 100 per cent as a part of commercialisation you need to be thinking about how to get businesses ready to adopt this technology.”

But Foster also believes we may be too fixed on trying to estimate the arrival of the supercomputer. “There are other things that are important to consider that could be happening now,” she says.

She is referring to attacks known as ‘harvest now, decrypts later’, in which cybercriminals may be hacking data now and storing it until the day they have the quantum resources to break it down. Two weeks ago, Meta highlighted this as a root factor for the looming threat of a “quantum apocalypse”.

“We have a new government now, and we know that there is going to be a lot of uncertainty, especially around the budget,” Foster says. “So what is key is to build on the successes and continue to build and push forward the UK as a leader in quantum or risk losing out on all of this fantastic advantage that we have built already.”

As we leave the hub, Buller looks ahead, explaining that the quantum internet could bring supercomputer-level processing power to the UK even before such supercomputers are fully realised, bringing radical benefits to healthcare.

“You would have multiple quantum processors that could be connected effectively and in a secure way,” he says. “That gives you much more computing power.

“There are quantum computing algorithms that could be used very effectively in, for example, drug discovery. These are problems that involve massive sorting, massive iterations, trials, etc, but a network of quantum processors would go through all the permutations it would take to find the right solutions – so you could discover a drug in a month instead of 10 years”.

He adds: “Ultimately the quantum internet is going to underpin a lot of what quantum technologies can accomplish on a bigger scale. But that will be a massive challenge because we need to connect quantum resources. It is the only way that can happen.”

One thing is clear, this is merely the beginning and there is still a long way to go, as Dr Adetunmise Dada, from Glasgow University’s Centre for Quantum Technology, tells Holyrood: “The UK has done a lot and is world-leading but there’s more to do. There’s a lot of areas of research that are crying out to be exploited and developed, and I think more funding will only push that even further at a faster pace.”