ultrix man page for crypt

crypt(1)						      General Commands Manual							  crypt(1)

Name
       crypt - encode/decode (available only if the Encryption layered product is installed)

Syntax
       crypt key < input.File > output.File

Description
       This reference page describes software that is available only if the Encryption layered product is installed.

       The  command reads from the standard input and writes on the standard output.  You must supply a key which selects a particular transforma-
       tion.  If no password is given, demands a key from the terminal and turns off printing while the  key  is  being  typed	in.   The  command
       encrypts and decrypts with the same key.

       Files encrypted by are compatible with those treated by the ed, ex and vi editors in encryption mode.

       The security of encrypted files depends on three factors: the fundamental method must be hard to solve, direct search of the key space must
       be infeasible, and sneak paths by which keys or clear text can become visible must be minimized.

       The command implements a one-rotor machine designed along the lines of the German Enigma, but with a 256-element rotor.	Methods of  attack
       on such machines are known, but not widely; moreover the amount of work required is likely to be large.

       The transformation of a key into the internal settings of the machine is deliberately designed to be expensive, for example, to take a sub-
       stantial fraction of a second to compute.  However, if keys are restricted to three lowercase letters, then encrypted files can be read	by
       expending only a substantial fraction of five minutes of machine time.

       Since  the  key	you choose is an argument to the command, it is potentially visible to users executing ps(1) or a derivative.  To minimize
       this possibility, destroys any record of the key immediately upon entry.  The most vulnerable aspect of is the choice of keys and key secu-
       rity.

Examples
       The following examples use KEY as the key to encrypt and decrypt files.	The first example encrypts the file naming the resulting encrypted
       file The second example decrypts the file naming the resulting decrypted file The third example prints the encrypted file in clear text.
       crypt KEY < plain.File > crypt.File
       crypt KEY < crypt.File > decrypt.File
       crypt KEY < crypt.File | pr

Files
       for typed   key

See Also
       ed(1), ex(1), vi(1), xsend(1), crypt(3), makekey(8)

																	  crypt(1)