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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 pro-
     gram, 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 eas-
     ily 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 isn't 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 bdes(1), openssl(1), pgp(1), or gpg(1).  However,
     restrictions for exporting, importing or using such tools might exist in
     some countries, so those stronger programs are not being shipped as part
     of the operating system by default.

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.

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