Is it ensure, insure, or assure?
(ICE) A contrived acronym for security software, coined by Usenetter Tom Maddox and popularised by William Gibson's cyberpunk SF novels. In Gibson's novels ICE software responds to intrusion by attempting to literally kill the intruder.
The term is not in serious use as of 2000 apart from the commercial software product, BlackICE and a growing number of others.
See also: icebreaker.