The Security of UNIX - the proposed unix-security

[greep%su-dsn at sri-unix.UUCP]

If you're worried mainly about outside people getting into the system,
as opposed to people who have legitimate accounts but want to login as
someone else, then a simple solution is to require a site password in
addition to the user's own password; that is, both have to be entered
(eg the site password followed by a slash followed by the regular
password).  One net site actually used to do this for dialins and ptys.
The only problem is notifying all the users when the site password
changes.
		- greep