Analysis: fully functioning quantum computers will have have a serious impact on how we secure our online systems

This year's online attacks on the Health Service Executive (HSE) and NUI Galway focused attention again on cyber security. We all want to feel safe when going online and cyber security is concerned with keeping private what should be kept private. As a kid, you may have wanted to pass a message to a friend but didn't want anyone else to read it or, if they did, it wouldn’t make sense to them.

Cryptography, the science of secret writing, deals precisely with that: how to change your message so that it doesn’t make sense to others (encryption), and only the entity whom the message is addressed to can undo that change to read the original message (decryption).

From RTÉ Radio 1's Drivetime, HSE Chief Operations Officer Anne O'Connor and Sligo University Hospital's Fergal Hickey on the ongoing impact of this year's cyber attack on the health service

You can compare it with the security system of your door at home: only the people with a valid key can go in. A natural question to ask, then, is how secure is your locking system? There is not only one way to lock a door, so which is the best or the most secure? Clearly, there is no straight answer, but the harder it is for burglars to try to open your door, the more secure it is. The same definition of security applies to cryptography and cyber security: a system is more secure when it takes more effort to break into it.

The current encryption systems used when you go online are based on certain mathematical problems that are hard to solve by an outsider who doesn’t have access to all the information. For instance, if I give you two numbers to multiply them, say 1 117 and 10 111, it’s relatively easy for you to do that: 1 117 * 10 111 = 11 293 987. However, if I only give you the number 11 293 987 and ask you to find out its factors (the numbers that multiplied together give that number), which are 1 117 and 10 111, the task becomes quite hard for you and you would probably quit soon enough.

This is actually what happens when you go online. Your identity, messages or account details are encrypted in a different way using some mathematical procedure that is very hard to reverse by an eavesdropper. What is "hard" and what is not? Hard is defined here as a problem which takes too much time for a computer to solve it. Which computer? Any computer, but the only computers we know and have at home and work are referred to as classical computers.

From RTÉ Lyric FM's Cuture File on Classic Drive, Aisling Kelliher on the uncertain new horizons of quantum computing

However, the idea of having a quantum computer is now being widely explored and researched. A quantum computer uses quantum systems (very tiny particles) and the principles of quantum physics to perform computations.

Why bother if we already have computers? Well, because theoretically there are certain problems or tasks which are hard to solve for a classical computer, but that same task could be easier to solve for a quantum computer. That sounds great, right?

But, hold on, we defined cyber security by using hard problems for a classical computer, so someone could easily hack any system if they had a quantum computer. Theoretically, yes, but the good (and bad) news is that we are rather far from having a fully functioning quantum computer because it’s also extremely hard to make one. That’s why joint efforts are needed around the world to do more research into quantum computing.

This year's attacks show that hackers don't yet need quantum computers to hack into secure systems, whatever "secure" means.

Ireland will be hosting the 2nd European Quantum Technologies Virtual Conference between November 29th and December 2nd. and 2nd December 2021. This should be of interest to more than just researchers as the general public also need to know that quantum computing is a thing. In Ireland, researchers and quantum computer enthusiasts established QIreland as part of the QWorld global network with the main objective to popularise quantum computing and technologies.

Over 200 people, from school students, undergraduates and postgraduates to lecturers and researchers across maths, physics, data analysis and computer science, registered for QIreland's first online event last May. Irish participants were affiliated with 12 universities across the country, demonstrating that people are interested in learning more about quantum computing and such educational initiatives are crucial for the future.

You don't have to worry yet about your cyber security being compromised by the emergence of quantum computers. This year's attacks show that hackers don’t yet need quantum computers to hack into secure systems, whatever "secure" means.

The views expressed here are those of the author and do not represent or reflect the views of RTÉ