Updated Cryptographers have discovered a way to break the Advanced Encryption Standard used to protect everything from top-secret government documents to online banking transactions.
The technique, which was published in a paper (PDF) presented Wednesday as part of the Crypto 2011 cryptology conference in Santa Barbara, California, allows attackers to recover AES secret keys up to five times faster than previously possible. It introduces a technique known as biclique cryptanalysis to remove about two bits from 128-, 192-, and 256-bit keys.
“This research is groundbreaking because it is the first method of breaking single-key AES that is (slightly) faster than brute force,” Nate Lawson, a cryptographer and the principal of security consultancy Root Labs, wrote in an email. “However, it doesn't compromise AES in any practical way.”