Securing systems is a race against time – Nokia's senior scientist

Securing systems before quantum computers become a reality is a race against time, Nokia’s scientist believes.

“The multiverse remains a theoretical concept, not a verified reality.”

And just like that, Aritra Banerjee, a senior research scientist at Nokia, shattered the excitement I felt after Google announced its Willow chip.

In a short period of time, two major quantum breakthroughs were announced. Namely, it was Google and its Willow chip with a hint of a multiverse. Then, Microsoft followed with Majorana 1, which leverages the world’s first topoconductor.

Both major announcements might mean that Q-Day – the day of quantum supremacy over classical encryption – is years, not decades away.

Why does it matter? Well, in simple terms, if we’re not ready, it could lead to a huge leak of secrets, from intellectual property to secret government data. Q-Day, if we aren’t prepared, could destroy governments and bitcoin.

Nokia is also researching topological units, and Banerjee believes “topological-qubit advancements are definitely bringing us closer to creating a meaningful quantum computer.”

Now, let's hear from Banerjee himself as we catch up on the latest quantum news that makes a difference.

If this interview reads like it was written as a Q&A, it’s because it was.

Should we trust post-quantum cryptography? Many attempts (and some successful ones) have been made to crack cryptography that is supposed to be safe from quantum computers, yet it was cracked using today’s technology.

Post-quantum cryptography (PQC) is emerging as a powerful tool to safeguard data against quantum attacks, with private companies already integrating it into their security protocols. Yet, it’s far from “bulletproof” – in fact, irrelevant of the technology, we should never consider anything 100% secure. Simply having this understanding enables a more comprehensive and responsible approach to risk management and mitigation.

As data security evolves and AI advances – potentially exploiting vulnerabilities in PQC, the ICT industry must adopt a multi-layered approach to protect against quantum threats. A defense-in-depth strategy, combining physics-based solutions with symmetric distribution and quantum key distribution, offers strong protection. Still, further testing and verification are essential, as we can’t yet be certain these algorithms can fully withstand quantum attacks.

What’s your take on Microsoft’s new chip, Majorana 1? Does it bring Q-Day any closer?

Microsoft’s topological quantum computing news is significant, and I congratulate them on their results. Anything that furthers the science behind topological qubits will only advance the overall progress toward creating meaningful quantum computers. Nokia is also researching topological qubits, and we are on a similar timeline to producing a viable topological quantum computer, having achieved the same milestones as Microsoft. In fact, we believe we have an edge. While Microsoft has demonstrated a topological qubit that can maintain a quantum state for two milliseconds, we’ve been able to maintain a quantum state for hours or even days at a time. This will be key to creating highly stable qubits, which will lead to both practical and powerful quantum computers in the future.

These topological-qubit advancements are definitely bringing us closer to creating a meaningful quantum computer that can efficiently solve advanced problems. But a meaningful quantum computer isn’t a cryptographically relevant quantum computer, or CRQC. Quantum computers would need to advance dramatically before they are capable of cracking the encryption that protects today's data and communications. It’s too early to say whether topological quantum computers would bring us to a CRQC – and thus Q Day – any faster.

What about Google’s new chip, Willow? Does it bring the Q-day any closer?

Google’s Willow is a big advancement in quantum computing. It’s one of several very promising projects, including Nokia’s own topological quantum computing research. Willow is a game-changer in terms of speed and accuracy. It can perform a computation in under five minutes – something that would take conventional computers 10 septillion years to complete.

Beyond this, Willow significantly reduced the error tendencies of some of its predecessors and has paved the way for scaling up even more powerful systems. These advancements point to a future where quantum computing fuels breakthroughs in AI and drug discovery. While Willow brings us closer to Q-Day, it’s not quite the moment of full-scale quantum computing, but it undeniably showcases the immense potential of these systems.

Do we have enough time to prepare for the Q-day with cryptography? Will we secure our systems sooner than the fully functioning and fault-proof quantum computers arrive?

Securing systems before quantum computers become a reality is a race against time – but one we can try to win with proactive action. The National Institute of Standards and Technology (NIST) has finalized the first three PQC algorithms that will form the backbone of a global defense strategy against the disruptive potential of quantum computing. These algorithms introduce complex mathematical challenges that would take a CRQC a significant time to solve, marking a vital first step in safeguarding sensitive data and critical systems.

Many are talking about the “harvest now, decrypt later” concept. Is that something you are worried about too?

Yes, the “harvest now, decrypt later” concept is a very real concern. Cryptography experts warn that opportunistic hackers are already collecting and storing vast amounts of sensitive data – ranging from consumer identity details to state secrets – waiting for the day they can decrypt it with more advanced technology. This poses significant risks to organizations of all sizes.

To stay ahead of this threat, we need to tackle challenges head-on with a mix of engineering efforts, proactive assessments, and the strategic adoption of advanced technologies. It is never too early to protect against what we know will eventually happen – Q-Day. Hindsight is always 20/20, so we are helping people protect themselves. This way, they don’t have to look back and wonder why they didn’t take a different approach.

What are you doing at Nokia in regard to quantum computing?

We’re excited about Nokia’s quantum computing research into the topological qubit, which we feel has the potential to create extremely powerful quantum computers that are small, low-cost, and highly efficient. The qubit is the fundamental building block of quantum computing, and hundreds of thousands of these qubits will need to be entangled to create a quantum computer that can solve hypercomplex problems. The problem is that the first generation of qubits being used today are inherently unstable. They lose their computational capabilities in milliseconds.

We are working on a new type of qubit that uses topology to make them inherently stable. This topological qubit will hold its quantum state – and therefore its stability – for days or weeks at a time. We could use these topological qubits to build quantum computers at a much lower cost and with a much smaller footprint, ultimately making quantum computers much more practical. Our Nokia Bell Labs quantum computing team has been at this for years, but we’re nearing some key breakthroughs and should be making some announcements later this year.

Could quantum computers really prove the existence of a multiverse?

For now, no. Today’s quantum computers can’t directly prove a multiverse exists and most scientists consider such claims speculative. While quantum computing showcases incredible potential, it doesn’t provide empirical proof of parallel universes – at least not yet. The multiverse remains a theoretical concept, not a verified reality.