Source : Free On-Line Dictionary of Computing

security through obscurity
     
         Or "security by obscurity".  A term applied by
        hackers to most {operating system} vendors' favourite way of
        coping with security holes - namely, ignoring them,
        documenting neither any known holes nor the underlying
        security {algorithms}, trusting that nobody will find out
        about them and that people who do find out about them won't
        exploit them.  This never works for long and occasionally sets
        the world up for debacles like the {RTM} worm of 1988 (see
        {Great Worm}), but once the brief moments of panic created by
        such events subside most vendors are all too willing to turn
        over and go back to sleep.  After all, actually fixing the
        bugs would siphon off the resources needed to implement the
        next user-interface frill on marketing's wish list - and
        besides, if they started fixing security bugs customers might
        begin to *expect* it and imagine that their warranties of
        merchantability gave them some sort of rights.
     
        Historical note: There are conflicting stories about the
        origin of this term.  It has been claimed that it was first
        used in the {Usenet} newsgroup in {news:comp.sys.apollo}
        during a campaign to get {HP}/{Apollo} to fix security
        problems in its {Unix}-{clone} {Aegis}/{DomainOS} (they didn't
        change a thing).  {ITS} fans, on the other hand, say it was
        coined years earlier in opposition to the incredibly paranoid
        {Multics} people down the hall, for whom security was
        everything.  In the ITS culture it referred to (1) the fact
        that by the time a {tourist} figured out how to make trouble
        he'd generally got over the urge to make it, because he felt
        part of the community; and (2) (self-mockingly) the poor
        coverage of the documentation and obscurity of many commands.
        One instance of *deliberate* security through obscurity is
        recorded; the command to allow patching the running ITS system
        ({altmode} altmode control-R) echoed as $$^D.  If you actually
        typed alt alt ^D, that set a flag that would prevent patching
        the system even if you later got it right.
     
        [{Jargon File}]
     
        (1994-12-15)