crypt provides acess to two algorithms for password encryption.
One it's based on the Data Encryption Standard algorithm with
variations intended (among other things) to discourage use of
hardware implementations of a key search. key is a user's typed
password. By taking the lowest 7 bit of each character of the
key, a 56-bit key is obtained. This 56-bit key is used to
encrypt repeatedly a constant string (usually a string
consisting of all zeros). The returned value points to the
encrypted password, a series of 13 printable ASCII characters
(the first two characters represent the salt itself). The return
value points to static data whose content is overwritten by each
call. Warning: The key space consists of 2 56 equal 7.2e16
possible values. Exhaustive searches of this key space are
possible using massively parallel computers. Software, such as
crack(1)?, is available which will search the portion of this
key space that is generally used by humans for passwords. Hence,
password selection should, at minimum,