This is really, really cool: using a single construction to provide … everything. It does feel a bit like putting all of one's eggs in one basket, but I guess as long as it's one really <i>great</i> basket that's okay.<p>It makes sense, too, given the assumptions we make about security of PRFs: if a PRF is secure enough to generate keys with PRF(state || 001), PRF(state || 002), … then intuitively (which isn't a proof!) everything else follows.<p>All in all, a really neat result!<p>As an aside:<p>> Disco is the natural merge of the two projects<p>I've gotten used to seeing the verb 'ask' used as a noun instead of 'request,' and just within the last week saw the verb 'solve' used as a noun instead of 'solution'; this is the first time I've seen the verb 'merge' used instead of the noun 'merger' in this context (although I'm familiar with it from version control).<p>American English has already lost its adverbs; I wonder if we'll start to lose a lot of our nouns (!) too.