"tptacek's law: given enough time, diametrically opposed algorithms will have the same name"

Yes! See: quicksort.

Huh? What's the other "quicksort" ? Tony's famous Quicksort I'm aware of, and while you should not use this algorithm this century† in its pure form it's still in the core of good sorts, you just need other ingredients too.

So what's the diametrically opposed algorithms with the same name ?

† Don't tell C++ programmers, some of their standard libraries only stopped shipping quicksort as the default algorithm during the Biden administration.

So we just flip a sign in Bcrypt! Or flip a decision Boolean? Or a sort order?

Regardless it will be easy. Apply the inverse operation of the “introduce more slowness” operation.

Unfortunately, I have seen some software in my day, and I don’t think it will work. Just really perverse stuff.