The Blowfish Library

  Blowfish is a block cipher that operates on 64bit (8 byte) quantities.  It
uses variable size key, but 128bit (16 byte) key would normally be considered
good.  It can be used in all the modes that DES can be used.  This library
implements the ecb, cbc, cfb64, ofb64 modes.

  Blowfish is quite a bit faster that DES, and much faster than IDEA or RC2.
It is one of the faster block ciphers.