[tahoe-dev] What is the 100 year crypto KDF?

[Chris Palmer]

Jack Lloyd writes:

> - Built-in iteration support. I don't know if it is worth using
>   necessarily, considering the inputs will all be high-entropy rather
>   than human-{chosen,memorized,postitnoted} passwords, but it _may_
>   still offer benefits.

This is why I wonder if a KDF is necessary at all. As I understand it, there
is no security need to whiten, stretch, mangle, or noodlize the output from
(e.g.) /dev/urandom. Am I wrong, or only wrong for a specific Tahoe-LAFS
scenario?