What can quantum computers do?
Quantum computers aren’t just about doing things faster or more efficiently. They’ll let us do things that we couldn’t even have dreamed of without them. Things that even the best supercomputer just isn’t capable of.
They have the potential to rapidly accelerate the development of artificial intelligence. Google is already using them to improve the software of self-driving cars. They’ll also be vital for modelling chemical reactions.
Right now, supercomputers can only analyse the most basic molecules. But quantum computers operate using the same quantum properties as the molecules they’re trying to simulate. They should have no problem handling even the most complicated reactions.
That could mean more efficient products – from new materials for batteries in electric cars, through to better and cheaper drugs, or vastly improved solar panels. Scientists hope that quantum simulations could even help find a cure for Alzheimer’s.
Quantum computers will find a use anywhere where there’s a large, uncertain complicated system that needs to be simulated. That could be anything from predicting the financial markets, to improving weather forecasts, to modelling the behaviour of individual electrons: using quantum computing to understand quantum physics.
Cryptography will be another key application. Right now, a lot of encryption systems rely on the difficulty of breaking down large numbers into prime numbers. This is called factoring, and for classical computers, it’s slow, expensive and impractical. But quantum computers can do it easily. And that could put our data at risk.
There are rumours that intelligence agencies across the world are already stockpiling vast amounts of encrypted data in the hope that they’ll soon have access to a quantum computer that can crack it.
The only way to fight back is with quantum encryption. This relies on the uncertainty principle – the idea that you can’t measure something without influencing the result. Quantum encryption keys could not be copied or hacked. They would be completely unbreakable.
https://www.wired.co.uk/article/quantum-computing-explained