jBCrypt is a Java implementation of OpenBSD's
Blowfish password hashing code, as described in "A
Future-Adaptable Password Scheme" by Niels Provos
and David Mazières. This system hashes passwords
using a version of Bruce Schneier's Blowfish block
cipher, with modifications designed to raise the
cost of off-line password cracking and frustrate
fast hardware implementation. The computation cost
of the algorithm is parametised, so it can be
increased as computers get faster. The intent is
to make a compromise of a password database less
likely to result in an attacker gaining knowledge
of the plaintext passwords.