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How 'Absurd' Quantum Mechanics Can Make Computers More Secure

14/03/2014 12:15 GMT | Updated 14/05/2014 10:59 BST

Computers have changed our lives. We can "hang out" with friends on the other side of the world, do business with people we've never even met by email or video conference, manage our finances from thousands of miles away in an instant and work from home, from a train station, from an aeroplane or from the beach (if you have to). The problem with this new connected nirvana: it's not secure.

One of the greatest challenges of modern life is how to protect your online personal or business information. From the regular stories about bank accounts being hacked to the leaks of highly sensitive information from within supposedly secure government agencies, we are constantly reminded of how fragile the electronic threads that connect our world are.

Currently, computer security is largely based upon encrypting information using increasingly complex mathematical algorithms. In theory these algorithms are incredibly difficult to break, but ultimately if the people wanting to hack you get bigger and better processors, they can - and will - in time, break your code.

As a researcher I have become fascinated with the possibility of using quantum mechanics to create unbreakable security codes for computers. Quantum mechanics can be described as the study of the behaviour of matter and its interactions on the scale of atoms and subatomic particles. Though not a new scientific discipline - the initial work in this area goes back to the early 20th century - the application of quantum mechanics to information technology only started in earnest in the 1990s.

One of the fundamentals of quantum mechanics is that it allows matter to be in several states at the same time and even correlate in very mysterious ways. This paradoxical quality can be used to create computer codes which are protected by the laws of physics, not by the complexity of some algorithm.

How does it work? When you want to encrypt an electronic message, you first send the "key" to unlock the message, then the message. When you receive a quantum key, by the properties of quantum measurement, it will show you right away if a third party has hacked the process between you and the transmitter. So you will know not to send the message, keeping the information secure.

The problem comes when you try and use these codes in your everyday computers. Quantum particles are very delicate and lose their properties extremely quickly when they come into contact with our world. To take advantage of these particles we need to isolate them, truly and fully, and slow their movements by chilling them to temperatures sometimes as cool as 10-9 degrees above absolute zero. In the case of quantum encrypted information, photons are usually used, but these deteriorate when they travel even a few dozen kilometres. In addition, the interface between the quantum particles and ordinary computers is not yet fault-free, and is open to being hacked. This has limited the power of quantum technologies up until now and is the focus of quite a lot of research.

In 2009 I started work on my PhD at Imperial College with a grant from the AXA Research Fund. AXA is supporting more than 400 academic projects around the world looking at different kinds of risk - from climate change to economic crises - and was interested in my work because it helped understand the growing issues of cyber security, notably for financial transactions or data privacy.

My work, which has now taken me to MIT, an institution at the cusp of nanotechnology research, has brought together quantum mechanics, computer science and even an element of materials science to look at how we can create materials that can make using quantum mechanics a reality for computers in offices or even homes.

We have been designing lasers, which are themselves streams of quantum particles, to supercool ions so that we can drive them into the quantum regime, building on the work of David Wineland on the so-called ion trap that won him the Nobel Prize for physics in 2012.

The process is complex but essentially works by extracting heat from the ion so that it behaves like a super-cooled particle - one that is completely stopped. With the ion trap and lasers, we can create a stable "quantum" particle, which can be in two states at the same time. Each additional particle will double the number of different states that can be superposed at the same time. Two particles can form four states, four equal 16 and so on. Only ten particles are needed to achieve 1024 independent states. Very quickly, one obtains a tremendous computing power, which has enormous consequences by itself. In addition, it can assist us in creating unbreakable computer codes and unhackable computers by regenerating the particles that carry quantum keys.

One of the great pioneers of quantum mechanics, the US physicist Richard Feynman, said that quantum mechanics deals with "nature as she is - absurd." We are trying to use that "absurdity" to make everyone's lives more secure.

Javier Cerrillo is a Postdoctoral Associate at Massachusetts Institute of Technology. His work on this area was funded by the AXA Research Fund