Revelations of the extent of government surveillance have thrown a spotlight on the security – or lack thereof – of our digital communications.
Even today’s encrypted data is vulnerable to technological progress. What privacy is ultimately possible? In the 27 March issue of Nature, the weekly international journal of science, researchers Artur Ekert and Renato Renner review what physics tells us about keeping our secrets secret.
In the history of secret communication, the most brilliant efforts of code-makers have been matched time and again by the ingenuity of code-breakers. Sometimes we can even see it coming. We already know that one of today’s most widely used encryption systems, RSA, will become insecure once a quantum computer is built.
But that story need not go on forever. “Recent developments in quantum cryptography show that privacy is possible under stunningly weak assumptions about the freedom of action we have and the trustworthiness of the devices we use,” says Ekert, Professor of Quantum Physics at the University of Oxford, UK, and Director of the Centre for Quantum Technologies at the National University of Singapore. He is also the Lee Kong Chian Centennial Professor at the National University of Singapore.
Over 20 years ago, Ekert and others independently proposed a way to use the quantum properties of particles of light to share a secret key for secure communication. The key is a random sequence of 1s and 0s, derived by making random choices about how to measure the particles (and some other steps), that is used to encrypt the message. In the Nature Perspective, he and Renner describe how quantum cryptography has since progressed to commercial prospect and into new theoretical territory.
Even though privacy is about randomness and trust, the most surprising recent finding is that we can communicate secretly even if we have very little trust in our cryptographic devices – imagine that you buy them from your enemy – and in our own abilities to make free choices – imagine that your enemy is also manipulating you. Given access to certain types of correlations, be they of quantum origin or otherwise, and having a little bit of free will, we can protect ourselves. What’s more, we can even protect ourselves against adversaries with superior technology that is unknown to us.
"As long as some of our choices are not completely predictable and therefore beyond the powers that be, we can keep our secrets secret," says Renner, Professor of Theoretical Physics at ETH Zurich, Switzerland. This arises from a mathematical discovery by Renner and his collaborator about 'randomness amplification': they found that a quantum trick can turn some types of slightly-random numbers into completely random numbers. Applied in cryptography, such methods can reinstate our abilities to make perfectly random choices and guarantee security even if we are partially manipulated.
“As well as there being exciting scientific developments in the past few years, the topic of cryptography has very much come out of the shadows. It’s not just spooks talking about this stuff now,” says Ekert, who has worked with and advised several companies and government agencies.
The semi-popular essay cites 68 works, from the writings of Edgar Allen Poe on cryptography in 1841, through the founding papers of quantum cryptography in 1984 and 1991, right up to a slew of results from 2013.
The authors conclude that “The days we stop worrying about untrustworthy or incompetent providers of cryptographic services may not be that far away”.
Senior Manager (Media Relations)
Office of Corporate Relations
National University of Singapore
DID: +65 6516 5399
Carolyn FONG | newswise
Simulation and Virtual Reality: Virtual Trade Fair Tour on the Smartphone
27.04.2015 | Siemens AG
A silver lining
24.04.2015 | University of California - Santa Barbara
KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.
Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...
A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...
Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.
Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...
Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.
In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...
23.04.2015 | Event News
23.04.2015 | Event News
13.04.2015 | Event News
27.04.2015 | Life Sciences
27.04.2015 | Power and Electrical Engineering
27.04.2015 | Life Sciences