from
Jargon File (4.4.4, 14 Aug 2003)
screaming tty
n.
[Unix] A terminal line which spews an infinite number of random
characters at the operating system. This can happen if the terminal is
either disconnected or connected to a powered-off terminal but still
enabled for login; misconfiguration, misimplementation, or simple bad
luck can start such a terminal screaming. A screaming tty or two can
seriously degrade the performance of a vanilla Unix system; the
arriving "characters" are treated as userid/password pairs and tested
as such. The Unix password encryption algorithm is designed to be
computationally intensive in order to foil brute-force crack attacks,
so although none of the logins succeeds; the overhead of rejecting
them all can be substantial.
from
The Free On-line Dictionary of Computing (8 July 2008)
screaming tty
[Unix] A terminal line which spews an infinite number of
random characters at the operating system. This can happen if
the terminal is either disconnected or connected to a
powered-off terminal but still enabled for login;
misconfiguration, misimplementation, or simple bad luck can
start such a terminal screaming. A screaming tty or two can
seriously degrade the performance of a vanilla Unix system;
the arriving "characters" are treated as userid/password pairs
and tested as such. The Unix password encryption algorithm is
designed to be computationally intensive in order to foil
brute-force crack attacks, so although none of the logins
succeeds; the overhead of rejecting them all can be
substantial.
[{Jargon File}]