Quantum technology seems to be all over the news at the moment, and quantum computing, in particular. This is because it is attracting lots of investment, and there is a lot of excitement about the potential benefits it can offer in the long run.

Discussions seem to involve mysterious “qubits”, “entanglement” and more. Quantum physics can sound pretty weird, even if we don’t really see this in everyday life. However, in the same way you don’t need to be an expert in semiconductor band gaps to use a transistor-based computer, you shouldn’t actually need a PhD in quantum physics to start thinking about the risks and opportunities that quantum computing can offer.

Quantum computing has massive long-term potential to transform society, by enabling new types of computations, but is also a field full of myths and misconceptions. In particular, quantum computers cannot just do the same calculations as today’s computers only faster/better/cheaper. Nor do they work by “trying all solutions at once”. And they certainly don’t prove that they are leveraging the computational power across multiple universes, no matter what headlines you might see.

Instead, quantum computers introduce a completely new paradigm of computing, one which might enable new types of calculations that are intractable using current computers. Finding potential quantum algorithms, and the problems they could solve, is an active area of research. Potential candidates include discovering novel drugs, or solving complex optimisation problems like train scheduling.

Another thing that quantum computers turn out to be good at doing is factoring large numbers. This might sound esoteric, but it could potentially impact some forms of encryption – leading to some to predict a “quantum apocalypse”. We’ll discuss the potential impact of quantum computing on encryption in a future post, but suffice to say that the true impact is again much more nuanced than the headlines. Not all encryption is at risk, and there is a long way to go before the technology threatens some modern encryption standards.

Although many organisations have developed quantum computing platforms, current systems are very much experimental prototypes. There is a lot of scientific and engineering work needed to scale these up to the point where they could challenge modern encryption standards. Estimates vary, but such a scenario is probably between 5-15 years away. Even when the first such systems arrive, they will be very few of them, and each one will probably take several days to decrypt a single session of network traffic - so there will be no “Q-Day” when suddenly all encryption becomes useless.

While there is a need to be aware of the potential risks and prepare for them, organisations should also be thinking about the opportunities. As we’ve noted above, a quantum computer can’t just run existing programs or algorithms and be faster. To take advantage, we need to identify problems that can’t feasibly be solved with current computers, and where we can design algorithms to solve them efficiently on a quantum computer. Having the hardware to do so effectively may be several years away, but it might also take many years to find and match problems and algorithms that can have significant impact. A lot of investment is going into building quantum computers, but we need to be ready for them when a large scale useful quantum computer finally arrives.