Blowfish uses block encryption with a 64-bit key of variable length. The algorithm has two stages: key expansion and data encryption itself. Key expansion transforms a key into a 448-bit key. Data encryption is based on a sixteen iteration Feistel network. One of the main benefits of this algorithm is speed: most of the time is spent on key expansion which is performed only once.
FastTrackFTP supports DES, TripleDES, Blowfish, Twofish256, Twofish192, Twofish128, AES256, AES192, AES128, Serpent256, Serpent192, Serpent128, ARCFOUR, IDEA, and CAST128.