Interesting. How long did it take to sign? Also, though I wasn't sure (which is why I didn't mention it), I thought one of the reasons keys were so short back then was due to the US classifying encryption algorithms as munitions, which made working with actually secure encryption standards difficult for developers. I would have expected the longest key would be 1024 bits, at a stretch. Even that is barely crackable today.

(I always thought the smaller keys options were there to accommodate much lower-end hardware or limited resources - ie. embedded systems ...)