Did the NSA put a backdoor in a new encryption standard?

Autonomist0 — Fri, 16 Nov 2007 00:04:00 GMT

Because the government is a major consumer of crypto products, government entities create or approve most of the encryption standards used in the industry. One of the key ingredients of crypto technology are random number generators. Getting random numbers from a computer is a very tricky problem, so the U.S. government actually publishes random number algorithms created by computer scientists and government agencies. This year, the government produced a new standard, which may soon be integrated into crypto software worldwide. Three of the four algorithms in the standard are based on industry standards, but one comes from the National Security Agency. The NSA's algorithm is more complex and slower than the others, so many people wondered why the NSA pushed to have it included.

In a recent CRYPTO 2007 conference, some computer scientists discovered that the algorithm has a possible backdoor key, which allows the numbers it generates to be predicted. While we don't know whether the NSA has the key, we can be sure that either it has the key or it released a dangerously broken standard. (Now that the vulnerability is known, vendors are unlikely to use it, so the NSA wouldn't have knowingly released a faulty standard unless it had the key.)

A paranoid person might wonder if having failed to force broken crypto on us at the hardware level, the government has some kind of nefarious plan to sneak one in. Simply requiring that the standard be used by government contractors might be sufficient to get it adopted by the industry due to its market share. People take much more care in selecting and testing encryption algorithms than random number generators.

Reassuring answers on this issue are not likely to be forthcoming, so here are some rules of thumb:

Real security requires evaluating the whole process, not just a good encryption algorithm.
Don't trust a security solution just because it is widely used or government approved.
Don't trust a security solution that is isn't open to peer review.

Crypto-Autonomist : security

Did the NSA put a backdoor in a new encryption standard?