Intrusion Countermeasures Electronics (ICE) is a term used in cyberpunk literature to refer to security programs which protect computerized data from being accessed by hackers.
The term was popularized by William Gibson in his short story "Burning Chrome", which also introduced the term cyberspace, and his subsequent novel Neuromancer. According to the Jargon File, as well as Gibson's own acknowledgements, the term ICE was originally coined by Tom Maddox.
When viewed in a cyberspace virtual reality environment, these constructs are often represented by actual walls of ice, stone, or metal. Black ICE refers to ICE that are capable of killing the intruder if deemed necessary or appropriate; some forms of black ICE may be artificially intelligent.
Though real-life firewalls, anti-virus software and similar programs fall under this classification, the term has little real world significance and remains primarily a science fiction concept. This can be attributed to the fact that using the term "electronics" to describe software products (such as firewalls) is something of a misnomer.
Nevertheless, the term ICE has recently been adopted by real-world software manufacturers:
On April 28, 2009, the Information and Communications Enhancement Act, or ICE Act for short, was introduced to the United States Senate by Senator Tom Carper to make changes to the handling of information security by the federal government, including the establishment of the National Office for Cyberspace.