On Sat, Nov 09, 2013 at 08:28:17PM -0800, d.nix wrote:
surely someone here has an opinion...
From the page, a relevant suggestion:
WARNING: DO NOT USE BEACON GENERATED VALUES AS SECRET CRYPTOGRAPHIC KEYS. The Beacon is a potentially useful service. Folks have implemented similar semantics by, for example, hashing the DJIA closing value of a given date (see http://xkcd.com/426/). NIST's implementation, of course, makes them a trusted third party to any security critical applications of this oracle. I'd be more comfortable with a cryptographic hash of an unpredictable but publicly determined value; however, it's hard to find one that has as much entropy as the Beacon. For example, suppose you use the low bits of the bitcoin blockchain hash. An attacker with 10% of the hash power could probabilistically attack such a system by chosing blocks with a specific value in those bits; furthermore, the miners might know the relevant value earlier than other users of the system. -andy