Module Crypt_des


module Crypt_des: sig .. end
DES, created by the NSA, is a 64 bit block cipher, so the following applies:

module Cryptsystem: Cryptsystem_64.T 
module Cryptmodes: Cryptmodes_64.T  with type key = Cryptsystem.key

Key management functions:

Although only 56 bits count a DES key is written with 64 bits. The extra bits are used for parity checking.

val check_parity : string -> unit
Checks that the parity of the key given as string is ok. The string must have a length of 8 characters.
val set_parity : string -> string
Sets the parity bits in the given key and returns a new string.

- DES has been heavily studied and seems to have a rather good design