Computer Scientists Achieve ‘Crown Jewel’ of Cryptography – Quanta Magazine

November 10, 2020 By admin

In 2018, Aayush Jain, a graduate student at the University of California, Los Angeles, traveled to Japan to give a talk about a powerful cryptographic tool he and his colleagues were developing. As he detailed the team’s approach to indistinguishability obfuscation (iO for short), one audience member raised his hand in bewilderment.

“But I thought iO doesn’t exist?” he said.

At the time, such skepticism was widespread. Indistinguishability obfuscation, if it could be built, would be able to hide not just collections of data but the inner workings of a computer program itself, creating a sort of cryptographic master tool from which nearly every other cryptographic protocol could be built. It is “one cryptographic primitive to rule them all,” said Boaz Barak of Harvard University. But to many computer scientists, this very power made iO seem too good to be true.

Computer scientists set forth candidate versions of iO starting in 2013. But the intense excitement these constructions generated gradually fizzled out, as other researchers figured out how to break their security. As the attacks piled up, “you could see a lot of negative vibes,” said Yuval Ishai of the Technion in Haifa, Israel. Researchers wondered, he said, “Who will win: the makers or the breakers?”

“There were the people who were the zealots, and they believed in [iO] and kept working on it,” said Shafi Goldwasser, director of the Simons Institute for the Theory of Computing at the University of California, Berkeley. But as the years went by, she said, “there was less and less of those people.”

Now, Jain — together with Huijia Lin of the University of Washington and Amit Sahai, Jain’s adviser at UCLA — has planted a flag for the makers. In a