4.3BSD-Reno/share/man/cat1/des.0

DES(1)			    UNIX Reference Manual			DES(1)

NNAAMMEE
     ddeess - DES file encryption

SSYYNNOOPPSSIISS
     DDeess --ee [bh] [--kk _k_e_y]
     ddeess --ff [bh] [--kk _k_e_y]

DDEESSCCRRIIPPTTIIOONN
     ddeess is a filter that encrypts or decrypts standard input to standard out-
     put with the Data Encryption Standard (DES).

     Options:

     --ee    (encrypt)
     --dd    (decrypt)
	   Either --ee or --dd must be specified.

     --kk    If the key is not given on the command line with the --kk option the
	   command will prompt for it twice, suppressing echo and comparing
	   the two responses to guard against mistyping.

     --hh    The --hh flag controls how the key string is to be interpreted.
	   Without the --hh flag, the key is an ASCII string.  Since DES ignores
	   the low order bit of each key byte, the high order bit is set for
	   odd parity, thus retaining the information contained in the low
	   order bit.  If the --hh flag is set, the key string is interpreted as
	   16 hex/ASCII characters; the low order bit of each byte is again
	   ignored as per the DES algorithm.  This allows the use of any arbi-
	   trary 56-bit key, including bytes representing control characters
	   that could not be typed if the -h option were not used.

     --bb    Electronic Code Book (ECB) mode is used.  By default, DES Cipher
	   Block Chaining (CBC) mode is used, with an initial vector (IV) of
	   all zeros.

	   Except for the --hh option, this command is compatible with the ddeess
	   command on the Sun Microsystems workstation.


SSEEEE AALLSSOO
     Sun Microsystems DES(1) manual page, which describes in detail how the
     length of the file is encoded in the last block of ciphertext.

AAUUTTHHOORR
     Phil Karn, KA9Q

HHIISSTTOORRYY
     4.3Reno BSD.