LOGIC BOMB

noun (Science and Technology) A set of instructions surreptitiously included in a computer program such that if a particular set of conditions ever occurs, the instructions will be put into operation (usually with disastrous results). Etymology: Formed by compounding: the equivalent of a time bomb, metaphorically speaking, except that it is a particular set of circumstances built into the logic of the program, rather than the passage of time, that will set it off. A similar set of instructions designed to be implemented on a given date is in fact called a time bomb in computing but the distinction between the two terms is not always clearly made. History and Usage: The logic bomb is one of a number of malicious or even criminal uses of computing know-how that have been invented since computers became widely accessible and affordable in the second half of the seventies. It has been used as a way of destroying evidence of a computer fraud as soon as information which might lead to the culprits is accessed, as the basis for blackmail, and as a way for a programmer to take revenge on an employer by causing the system to crash mysteriously. If you damage someone's computer--whether by attacking it with a hammer or crippling the program with a logic bomb--it's...a crime. Independent 21 Sept. 1988, p. 2 Slip a logic bomb into the development software; it'll be copied along with the valid programs and shipped to the rest of the country. Clifford Stoll The Cuckoo's Egg (1989), p. 232 See also Trojan, virus, and worm