Blowfish is an block cipher encryption algorithm invented by Bruce Schneier. 

  

 ;:Blowfish is a symmetric block cipher that can be used as a drop-in replacement for [DES] or [IDEA]. It takes a variable-length key, from 32 bits to 448 bits, making it ideal for both domestic and exportable use. Blowfish was designed in 1993 by Bruce Schneier as a fast, free alternative to existing encryption algorithms. Since then it has been analyzed considerably, and it is slowly gaining acceptance as a strong encryption algorithm. Blowfish is unpatented and license-free, and is available free for all uses. -- http://www.schneier.com/blowfish.html