Yeah that's a comparison I drew down-thread as well (w/r/t a stream cipher). "Seed" was a poor choice of terminology on my part there - the point I was trying to convey is that you'll need a non-deterministic source, which is necessarily outside of software. I used the term "seed" as a shorthand for that (as if it were a stream cipher), but strictly speaking as you say that's not correct, as you'll be taking the random data directly as a key.

So no, you're not misunderstanding - I just communicated poorly!