crypt

ENIGMA(1)                   General Commands Manual                  ENIGMA(1)

NAME
     enigma, crypt — very simple file encryption

SYNOPSIS
     enigma [-s] [-k] [password]
     crypt [-s] [-k] [password]

DESCRIPTION
     The enigma utility, also known as crypt is a very simple encryption
     program, working on a “secret-key” basis.  It operates as a filter, i.e.,
     it encrypts or decrypts a stream of data from standard input, and writes
     the result to standard output.  Since its operation is fully symmetrical,
     feeding the encrypted data stream again through the engine (using the
     same secret key) will decrypt it.

     There are several ways to provide the secret key to the program.  By
     default, the program prompts the user on the controlling terminal for the
     key, using getpass(3).  This is the only safe way of providing it.

     Alternatively, the key can be provided as the sole command-line argument
     password when starting the program.  Obviously, this way the key can
     easily be spotted by other users running ps(1).  As yet another
     alternative, enigma can be given the option -k, and it will take the key
     from the environment variable CrYpTkEy.  While this at a first glance
     seems to be more secure than the previous option, it actually is not
     since environment variables can also be examined with ps(1).  Thus this
     option is mainly provided for compatibility with other implementations of
     enigma.

     When specifying the option -s, enigma modifies the encryption engine in a
     way that is supposed to make it a little more secure, but incompatible
     with other implementations.

   Warning
     The cryptographic value of enigma is rather small.  This program is only
     provided here for compatibility with other operating systems that also
     provide an implementation (usually called crypt(1) there).  For real
     encryption, refer to openssl(1), or gpg(1) (security/gnupg1).

ENVIRONMENT
           CrYpTkEy  used to obtain the secret key when option -k has been
                     given

EXAMPLES
           man enigma | enigma > encrypted
           Enter key: (XXX — key not echoed)

     This will create an encrypted form of this man page, and store it in the
     file encrypted.

           enigma XXX < encrypted

     This displays the previously created file on the terminal.

SEE ALSO
     gpg(1), openssl(1), ps(1), getpass(3)

HISTORY
     Implementations of crypt are very common among UNIX operating systems.
     This implementation has been taken from the Cryptbreakers Workbench which
     is in the public domain.

                                  May 8, 2018