bcrypt is a cross-platform file encryption tool. Files encrypted by it can be transferred on all supported operating systems and processors. The password must be 8 to 56 characters long and will be internally converted to a 448-bit key. bcrypt employs the Blowfish encryption algorithm, published by Bruce Schneier in 1993. Specifically, bcrypt uses Paul Crockers' implementation. The source code released with bcrypt makes minor modifications to the original version.