Crypt (Unix)

crypt
Original author(s)Robert Morris
Developer(s)AT&T Bell Laboratories
Initial releaseFebruary 1973; 51 years ago (1973-02)
Operating systemUnix, Unix-like, Inferno
TypeCommand

In Unix computing, crypt or enigma is a utility program used for encryption. Due to the ease of breaking it, it is considered to be obsolete.

The program is usually used as a filter, and it has traditionally been implemented using a "rotor machine" algorithm based on the Enigma machine. It is considered to be cryptographically far too weak to provide any security against brute-force attacks by modern, commodity personal computers.[1]

Some versions of Unix shipped with an even weaker version of the crypt(1) command in order to comply with contemporaneous laws and regulations that limited the exportation of cryptographic software. Some of these were simply implementations of the Caesar cipher (effectively no more secure than ROT13, which is implemented as a Caesar cipher with a well-known key).

  1. ^ crypt(1) – FreeBSD General Commands Manual