Re: [tlug] Are ordered hashes useful?

["Stephen J. Turnbull" <stephen@example.com>]

Raymond Wan writes:

 > 2)  The other reason is to give a unique key through hashing.  For
 > security reasons, you probably want the result of hashing to be
 > different between program runs or between systems or something.

But a hash can't do that, it's a deterministic algorithm and therefore
always gives the same answer from the same inputs.  The unifying
concept is "uniform chaotic distribution of values".  "Uniform" means
that no value is more probable than any other, so risk of collision is
minimized.  "Chaotic" means that inputs that are "close" to each other
do not give close outputs more frequently than they give widely
separated outputs.