py-bcrypt is a Python wrapper 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 (e.g. using John the Ripper).

py-bcrypt requires Python 2.4. Older versions may work, but the bcrypt.gensalt() method won't - it requires the cryptographic random number generator os.urandom() introduced in 2.4.

py-bcrypt is licensed under a ISC/BSD licence. The underlying Blowfish and hashing code implementation is taken from OpenBSD's libc and is subject to a 4-term BSD license. See the LICENSE file for details.