ENIGMA(1) BSD General Commands Manual ENIGMA(1)NAME
enigma, crypt — very simple file encryption
enigma [-s] [-k] [password]
crypt [-s] [-k] [password]
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 is not since environ‐
ment 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.
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) (ports/security/pgp), or
gpg(1) (ports/security/gnupg). 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
CrYpTkEy used to obtain the secret key when option -k has been
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
enigma XXX < encrypted
This displays the previously created file on the terminal.
SEE ALSObdes(1), gpg(1), openssl(1), pgp(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.
BSD May 14, 2004 BSD