[midas007]

Absolutely not, that would NOT SCALE.

Again, you're making accusations, shifting the conversation without providing evidence. Talking with you is pointless.

[tptacek]

So when I "derive a new key" for a sector when it gets "rewritten", that key comes from...

[makomk]

Presumably the sector key is derived from the master key using one of the numerous fast KDFs, with PBKDF used only to derive the master key from the password. That's the obvious way to do it and midas007 explicitly mentions PBKDF as a way to generate a master key from a password with sector keys derived from that master key using some unspecified technique. You appear to have come up with your own obviously daft way of implementing the suggestion and then criticized that rather than the original proposal. Please don't do that.