The CEO of Nvidia, Jensen Huang, is clearly a pretty smart guy, so the fact that he is turning his attention to quantum computing is significant. He says that there is an “” in the technology and that the industry is "within reach" of having quantum computers that are able solve some interesting problems in the coming years.

Now, the first thing I think about when someone mentions the interesting problems that quantum computers can solve is the ability to hack Bitcoin and get hold of hundreds of billions of dollars. A 2022 Hudson Institute study estimated that a quantum hack of bitcoin would cause across crypto and other markets, meaning that it would trigger a recession, and the cost of Bitcoin has soared since then, meaning the losses would be even higher. But when will this happen?

Huang had previously said that quantum computing was 15-30 years away, while the Microsoft co-founder Bill Gates, said earlier this year that he though useful quantum computers could arrive in as little as three to five years. In fact “There is the possibility that he [Nvidia founder and CEO Jensen Huang]

could be wrong. There is the possibility in the next three to five years that one of these techniques would get enough true logical Qubits to solve some very tough problems".

If Nvidia now see an inflection point, then it perhaps Mr. Gates is right and the reolution may be here sooner than many people think. After all, IBM has just announced detailed plans to build an error-corrected quantum computer with significantly more computational capability than existing machines by 2028. It hopes to make the computer available to users via the cloud by 2029. Starling will have 200 logical qubits, which will be constructed using the company’s chips. After Starling, it plans to build another, Blue Jay, which will contain 2000 logical qubits and is expected to be capable of a billion logical operations. While IBM’s roadmap aims for 4,000 qubits soon after, this is still below the 1 million qubit threshold estimated as necessary for breaking RSA-2048, in Japan, the National Research and Development Agency, RIKEN, in collaboration with the Japanese IT company Fujitsu, has developed a system with 256 qubits and says it aims to launch a 1,000-qubit computer in 2026.

Meanwhile, Microsoft has just announced that it has invented an entirely new kind of quantum computer which is on a path to create a single quantum computer more powerful than all classical computers on the planet. The company believes that this technology, under development for nearly two decades, will enable the construction of commercially usable and viable quantum computers within five years, which aligns again with Mr. Gates prediction.

Microsoft are far from alone in focusing on quantum. Amazon Web Services announced Ocelot, its first-generation nine quibit quantum computing chip. While the chip has limited computing capabilities—Amazon say it is a proof-of-principle demonstration that shows the architecture is scalable and hardware-efficient—it is a a step on the path to creating a larger machine that can deliver on the industry’s promised killer applications, such as fast and accurate simulations of new battery materials.

Bernard Marr is surely right to say that a couple of decades from now quantum computing will be changing the world yet, just as the leap to transistors and microchips enabled the digital world, but we can certainly imagine some of the ways that it could disrupt current systems by rendering widely-used asymmetric cryptography (which powers, for example, the padlock in your web browers address bar) useless. This is why I’ve written before about why banks need to start thinking about “Y2Q", which is when quantum computing will make some current encryption technology obsolete, and why quantum readiness should already be part of organisational strategies.

Well, maybe Y2Q is in sight now. Maybe Y2Q is 2028, which many people seem to think is the right timescale for organisations to complete post-quantum cryptography upgrades—not because quantum computers will definitely be ready by then, but because of uncertainty and the catastrophic risk if they arrive earlier than expected.

Last year (CEG), which was chaired by the US Department of the Treasury and the Bank of England, highlighted the potential cybersecurity risks associated with developments in quantum computing and the steps that must be taken for financial authorities and institutions to address those risks and, indeed, financial organisations are already preparing for the arrival of quantum computers. Retail, wholesale and central banks themselves are working to develop responses. The Banque de France (BDF) and the Monetary Authority of Singapore (MAS) have already completed a post-quantum cryptography (PQC) experiment designed to enhance cross-border payment security and future-proof financial transactions. By using Microsoft Outlook as the primary email client and incorporating a PQC email plugin, the BDF and MAS successfully exchanged encrypted emails, marking a crucial step toward protecting financial data from future quantum-powered cyber threats.

It seems appropriate, during the International Year of Quantum Science and Technology (the United Nations General Assembly declared 2025 as the International Year of Quantum Science and Technology to foster international partnerships, with a special focus on building capacity in the Global South, advancing gender equality in STEM fields, and tackling the "growing quantum divide”) to think about the implications of large scale quantum computer. While stealing Bitcoin may be an amusing benchmark for quantum prowess (after all, it does not really matter if Bitcoin goes to zero) the real threat to our way of life and well-being is not IBM or Amazon users subverting cryptocurrency but well-funded and highly-motivated nation state adversaries using quantum computers to wreak havoc across business, government and society as a whole.

And that may not even be most serious implication because in a related field, researchers at the Sussex Centre for Quantum Technologies that uses quantum computing to detect low frequency electronic fields, opening up the potential for brain scanning with unprecendented accuracy. James Stone, Professor of Psychiatry at Brighton and Sussex Medical School said: “It is an exciting discovery – with development it could open the way for much less intrusive and more detailed 3D imaging of electrical activity in brain, giving the potential to detect which parts of the brain are active in real-time, and potentially giving insights into how thoughts and sensations are represented in the brain”.

So it looks like having a quantum computer steal your cryptocurrency will be a minor inconvenience when compared to having a quantum computer steal your thoughts.