As computer data moves to the “cloud” – networks of shared, remote servers – security becomes more of a challenge. Ideally, users should be able to perform operations on their data with complete confidence that no one can peek over their virtual shoulders.
Research carried out at the Weizmann Institute and MIT 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.
“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, the first so-called fully homomorphic encryption (FHE) was demonstrated.
That early version of fully homomorphic encryption was time-consuming and unwieldy. But Brakerski, together with Dr. Vinod Vaikuntanathan (who was a student of Goldwasser’s at MIT), surprised the computer security world last year with two papers in which they described several new ways of making fully homomorphic encryption more efficient. They not only simplified the arithmetic, speeding up processing time, but showed that a mathematical construct called an ideal lattice, used to generate the encryption keys, could be simplified without compromising security.
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 the 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.
Prof. Shafrira Goldwasser’s research is supported by Walmart.