ANU researchers have created a crack-proof encryption system that’s got the nod from NASA. TEGAN DOLSTRA reports.

Your bank account details and medical records might be safe from prying eyes now, but who might be able to hack your secrets in 5, 20 or 50 years’ time?

In the digital age, encryption is crucial for keeping private information private. From major military and government records to email correspondence, encryption – disguising messages with a code – protects information from eavesdroppers who may have less-than-honourable intentions.

Current encryption systems have flaws – as ASIO and Sony can no doubt tell you. But QuintessenceLabs – a cyber security company developed by ANU researchers – has invented a crack-proof encryption system that has been attracting attention from some of the world’s largest organisations.

Secret codes have come a long way in the past 50 years, says QuintessenceLabs co-founder and ANU College of Physical and Mathematical Sciences researcher Dr Thomas Symul.

“If two people share a perfectly random code, they can communicate in total privacy. But how do you transmit that secret code in the first place?” he says.

“Spies used to write down a random number key in a notepad, which they carried in a briefcase to a secret location. They’d use the key to decode a message, then rip out the page and burn it.”

QuintessenceLabs’ breakthrough technology is essentially similar, but a little more complex. The first step involves generating a truly random number sequence. This is more difficult than it sounds: it’s been proven theoretically that it’s impossible to purposefully create a string of random numbers.

“You always need to start from somewhere – a time of day, your birthday, the date,” explains Symul. “And if someone can work out what that initial sequence was, your string of random numbers suddenly isn’t random at all.”

But this theoretical impossibility proved no obstacle for Symul, who developed a truly random number generator a couple of years ago. The trick was to look at the problem on a quantum scale.

“What we do is measure quantum processes that occur inside vacuum. Most people think vacuum has nothing in it, but it actually contains a little bit of energy. Pairs of particles and anti-particles are popping in and out of existence all the time, resulting in a randomly fluctuating field,” he says.

The next step is to transmit those random measurements from one place to another, using a laser and an optic fibre. The unique properties of the system mean anyone trying to tap into the signal will leave behind incriminating ‘fingerprints’.

“Quantum mechanics tells us that you cannot measure perfectly both the amplitude and the phase of a laser beam,” says Symul. “You can make a perfect amplitude measurement, but it adds a lot of noise to the phase measurement and vice versa. So if somebody tries to listen in on the transmission they’ll leave a mark.”

These tell-tale signs of interference enable the receiver to select only numbers that definitely haven’t been intercepted. They can then use them as a key to code and decode later transmissions.

Just like Cold War spies burning their secret keys after use, the QuintessenceLabs keys are unrecoverable.

“When you measure a quantum object, you destroy it in the process. So it’s impossible for somebody else to make the same measurements and therefore have the same secret key as you,” explains Symul. “That means you can be confident that your data will be safe forever.”

Earlier this year, QuintessenceLabs co-founder and CEO, and ANU alumnus, Dr Vikram Sharma, took the cutting-edge technology to New York for the IBM SmartCamp competition. The company outshone 3,000 competitors from around the world to finish in the global top three.

“It took a little while for the result to sink in,” says Sharma. “But when it did, I was really proud of the fantastic team we have at QuintessenceLabs and the fact that Australian innovation was on the world stage.”

The judges were impressed by the technology’s innovative laser usage – which gives it cost, size and performance advantages over conventional single-photon approaches.

“There are only a few groups in the world working with ‘bright lasers’ – most others use single-photon generators and detectors,” says Sharma. “By using bright lasers, we can use off-the-shelf components and integrate straight into existing infrastructure.”

These advantages have attracted interest from near and far.

“We can apply it to virtually every domain that uses electronic information. We’ve had interest from government agencies and some of the largest defence contractors in the world, such as Lockheed Martin and Boeing,” says Sharma.

“I’m also very pleased to say that we received an invitation from NASA to open an office at its Ames Research Park in Silicon Valley.”

As the makers of a truly unsolvable coding system, it’s no surprise QuintessenceLabs is attracting attention – and the more they attract, the safer your data will be from prying eyes.

This story appeared in ANU Reporter magazine. Read the full issue at http://news.anu.edu.au/publications/anu-reporter/