June 11, 2013
New Algorithm Solves Cloud Security Issues
Lee Rannals for redOrbit.com - Your Universe OnlineComputer Science and Artificial Intelligence Laboratory presented their work on a new encryption scheme for cloud computing at the Association for Computing Machinery´s 45th Symposium on the Theory of Computing .
Homomorphic encryption is a new research topic in cryptography that promises to make cloud computing perfectly secure. With the encryption theory, a Web user would send encrypted data to a server in the cloud, which would then process it without decryption and send back a still-encrypted result.
However, a downfall scenario of this idea would be attempting to search the server. If a user sent a search term to a server to find a specific record, the server would have no choice but to send back information on every record in the database. The MIT team says they have developed a solution solving this problem that involves a bit of a collaboration of many schemes.
The researchers built their functional-encryption scheme by fitting together several existing schemes, each of which has vital attributes of functional encryption, but none of which is entirely sufficient in itself. This new system begins with homomorphic encryption and embeds the decryption algorithm in a garbled circuit, which is when only the holder of a secret cryptographic key can encrypt data.
The key to the garbled circuit is protected by attribute-based encryption, which is a public-key system that is reusable but cannot reveal the output of a function without revealing the input. The team said their encryption scheme is layered in such a way that one use grants the server access to a general function rather than a single value.
“It´s an extremely surprising result,” said Ran Canetti, a professor of computer science at Boston University. “I myself worked on this problem for a while, and I had no idea how to do it. So I was wowed. And it really opens up the door to many other applications.”
He said the researchers' scheme will not be deployed any time soon, but is sure that "it's going to lead to more stuff."
“It´s an enabler, and people will be building on it," Canetti, who was not a part of the research, said.