ENCRYPT(1)

NAME
decrypt, encrypt, recrypt - encryption/decryption filters

SYNOPSIS
encrypt key <clear-text >encrypted

decrypt key <encrypted >clear-text

recrypt keyin keyout <input >output

DESCRIPTION
All three commands are filters, reading from the standard input and writing on the standard output. encrypt takes a clear text and encrypts it using the given key. decrypt takes a text which was encrypted using the given key and produces the original clear text. recrypt decrypts its standard input using keyin and re-encrypts it using keyout to its standard output. It has the same effect as

    decrypt keyin | encrypt keyout

except that it is more convenient, and on systems where pipes are implemented as temporary files it reduces the chance of the clear text becoming visible.

A key is a string of at least 14 ASCII characters (excluding NUL). Only the first 14 characters are significant. The internal 52-bit form of a key is never revealed. Alphabetic case in a key is ignored, so the same key may be used in a system where the command scanner ignores alphabetic case.

The encryption method used is quite fast (around 5000 characters per second on an 11/750). There is good reason to suppose that its most vulnerable point is the physical security of the key.

DIAGNOSTICS
"command must be {de,en,re}crypt" - there is actually only one program. It uses the command name to tell it what to do. This message means that the name you used didn't start with any letter in "dDeErR".

"missing decryption key"
"decryption key shorter than 14 characters"
"missing encryption key"
"encryption key shorter than 14 characters" - unlike the standard UNIX program crypt(1) these programs will not read a key from the terminal. When a key is provided it must be at least 14 characters long (but need not be any longer).

"file name arguments are not accepted" - these commands are pure filters, they do not accept file names as arguments like cat(1).

SEE ALSO
crypt(1), crypt(3)

AUTHOR
Richard A. O'Keefe, DAI Edinburgh