June 19, 2012, 3:15 PM — It took only 148 days, not hundreds of thousands of years, for security researchers in Japan to crack the 923-bit key to a next-generation encryption protocol.
Not that it was easy. The team from Fujitsu, Japan's National Institute of Information and Communications Technology (NICT) and Kyushu University ran advanced cryptanalysis techniques running on 21 PCs running a total of 252 processing cores in parallel to crack a document encrypted using pairing-based cryptography (PBC).
Unlike public-key cryptography, on which most current cryptographic schemes are based, pairing based cryptography doesn't rely on a single string of numbers or key-issuance authority for its encryption.
Instead it uses two groups of numbers that generate a third set when run through any of a series of formulae.
The encryption "key" comes from running values from each of the first two groups though a formula that delivers a result found in the third group, then removing one of the two original groups of numbers.
The sender of an encrypted email might use his or her own list of numbers "A" and a list supplied by the recipient of the email "B," to generate a third set "C" using a pre-defined formula.
The recipient can then decrypt the email using only number groups B and C, though with more difficulty than if he or she possessed groups A and B.
"The known implementations of these pairings – the Weil and Tate pairings – involve fairly complex mathematics," according to notes from a 2004 presentation at MIT by lecturers Ran Canetti and Ron Rivest. "Fortunately, they can be dealt with abstractly, using only the group structure and mapping properties."