fast des

how fast is fast des these days? (i have measured over 2 mbps on decent workstations.) i was in a meeting today attended by someone from nsa who said that 2.4 gbps des chips exists today. (he got real silent after blurting this out. hmm.) 2.4 gbps is 37.5 million des per sec. it is probably not much challenge to put together a 65,536 element machine, which would run at 2.5 trillion des per sec. if i have my arithmetic right, this could exhaustively test the space of 56 bit keys in about eight hours.