Up in a Cloud for Processing Computer Data

Share this article

A declining amount of today’s computing is done on desktop computers; cloud computing, in which operations are carried out on a network of shared, remote servers, is expected to rise as the demand for computing power increases.

This raises some crucial questions about security: For instance, can we perform computations on data stored in “the cloud” without letting anyone else see our information?

Research carried out at the Weizmann Institute and the Massachusetts Institute of Technology is moving us closer to the ability to work on data while it is still encrypted, giving an encrypted result that can later be securely deciphered.
Attempting computation on sensitive data stored on shared servers leaves that data exposed in ways that traditional encryption techniques can’t prevent. The main problem is that to manipulate the data, it has to be first decoded. “Until a few years ago, no one knew if the encryption needed for this sort of online security was even possible,” says Dr. Zvika Brakerski, who recently completed his Ph.D. in the group of Prof. Shafi Goldwasser of the Computer Science and Applied Mathematics Department.

In 2009, however, a doctoral student at Stanford University named Craig Gentry provided the first demonstration of so-called fully homomorphic encryption (FHE). His original method was extraordinarily time-consuming and unwieldy, making it highly impractical. Gentry constructed his FHE system by using fairly sophisticated math, based on so-called “ideal lattices”, and this required him to make new and unfamiliar complexity assumptions to prove security. Gentry’s use of ideal lattices seemed inherent to FHE; researchers assumed that they were necessary for the server to perform such basic operations as addition and multiplication on encrypted data.
Brakerski, together with Dr. Vinod Vaikuntanathan (who was a student of Goldwasser’s at MIT), surprised the computer security world earlier this year with two recent papers in which they described several new ways of making fully homomorphic encryption more efficient. For one thing, they managed to make FHE work with much simpler arithmetic, which speeds up processing time. And a surprise discovery showed that a mathematical construct used to generate the encryption keys could be simplified without compromising security. Gentry’s original ideal lattices are theoretical collections of points that can be added together – as in an ordinary lattice structure – and also multiplied. But the new research shows that the lattice does not have to be ideal, which simplifies the construction immensely.

“The fact that it worked was something like magic, and it has challenged our assumptions about the function of the ideal lattices in homomorphic encryption,” says Brakerski.
Their result promises to pave a path to applying FHE in practice. Optimized versions of the new system could be hundreds – or even thousands – of times faster than Gentry’s original construction. Indeed, Brakerski and Vaikuntanathan have managed to advance the theory behind fully homomorphic encryption to the point that computer engineers can begin to work on applications. These might include, for instance, securing medical information for research: A third party could perform large medical studies on encrypted medical records without having access to the individuals’ information.

 

Prof. Shafrira Goldwasser’s research is supported by Walmart.

Share this article

Latest news

Sensing Fat

Sensing Fat

New research from the Weizmann Institute of Science reveals that the nervous system can sense fat tissue and that blocking this ability protects mice from metabolic disorders. Popular belief holds that our senses gather information only about the external world, but...

Food: Friend, Not Foe – New Study Explains Why

Food: Friend, Not Foe – New Study Explains Why

Weizmann Institute of Science researchers have revealed the cellular network behind oral tolerance, the immune mechanism that enables us to eat food safely.  If we have an allergy to peanuts, strawberries or dairy, we are quick to blame our immune systems. But...

MRI Gets a Nano-Sized Upgrade

MRI Gets a Nano-Sized Upgrade

Weizmann Institute of Science researchers have achieved an MRI resolution of one billionth of a metre, paving the way for the most detailed images of individual molecules ever produced. This new development will play a major role in the materials and pharmaceutical...

Beyond Words

Beyond Words

Weizmann Institute researchers have revealed that the melody of spoken English functions as a distinct language, with a vocabulary and rules of syntax.  The findings lay the foundation for an AI that will understand language beyond just words. The AI revolution, which...

All embroidery colours

All embroidery colours

AI-based technology developed in Dr Liat Keren's lab at the Weizmann Institute of Science has shown it enables an unprecedented view of processes in body tissues. Artificial intelligence systems are working magic in many areas of the life sciences – they help decipher...