This code appears to have only cursory resemblance to Bruce Schneier's
blowfish and twofish algorithms in that it too has a table-based decoder.
Derivation from FairKeys code by Jon Lech Johanson at nanocrew.net.
If you don't know what that is, don't bother looking here further. This is
a Pure Perl implementation. I doubt there is any need for xs coding for
what would mainly be processing 16 bytes at a time. This code is part of an
ongoing effort to clone portions of the Apple iTMS in Perl for portability.
See www.hymn-project.org for prior efforts by others.