- "This is the far side of ice, the view of the matrix I've never seen before, the view that fifteen million legitimate console operators see daily and take for granted."
- —Automatic Jack
ICE (Intrusion Countermeasures Electronics) is the technology that protects a system from illegal intrusions. Inside the matrix ICEs appear as virtual wall structures of glowing strata. The walls form mazes and gates that open for legitimate transmissions. An ICE wall can also have windows, gaps, but also traps. The "primitive" ICE of the New York Public Library has several windows obvious to intruders.
An ICE has a pattern. One can study it as a 2d graphic representation on a monitor, in which case it looks like woven lines of neon. Thanks to an animation program, weaving lines show the internal functions. A first-class hacker like Bobby Quine could manipulate the pattern to resolve it for easier analysis; the pattern then is simplified to alternating between 2 configurations, and cuts in the flow (eg. to allow transmissions) become visible.
Illegal programs called Icebreakers are designed by hackers to break such defenses.
Core-command ice[]
This seems to be an emergency type of ICE. When The Russian program virus breached the first "gate" of Chrome's database, the bulk of her data vanished behind core-command ice. This appeared to the hackers as "leagues of corridor, mazes of shadow" blanking out everything. However the virus's mimetic programs still scanned for information that wasnt blanked or screened.
Black ice[]
- "That's king hell ice, Case, black as the grave and slick as glass. Fry your brain soon as look at you. We get any closer now, it'll have tracers up our ass and out both ears, be tellin' the boys in the T-A boardroom the size of your shoes and how long your dick is."
- —Dixie Flatline
An illegal type of ice that kills the hackers who attempt to pass it, functioning as a neural-feedback weapon "like an epileptic spasm that goes on and on" until the attacker's neural system is destroyed. It is part of the hacker rumors that one can hear in the Gentleman Loser, and supposedly is employed by Chrome. Automatic Jack indeed saw Black Ice inside the core of Chrome's database, frightening him.
The ice generated by the two Tessier-Ashpool AIs around the core of Villa Straylight was also lethal.