A common problem in computer systems is the presence of malfunctioning components that may fail entirely or else may perform erratically. There are different faults that components may undergo, to exhibit different classes of failure. Generally, fail-stop failures (failures where a component simply stops functioning) are considered the easiest to deal with. The most difficult failures are the Byzantine failures, where a component may behave arbitrarily, including giving conflicting information to different parts of the system. Byzantine failures have at least as much nuisance value as fail-stop failures, because a Byzantine component can also exhibit fail-stop behavior.

The term "Byzantine" in this context comes from a paper titled "The Byzantine Generals Problem" written by Leslie Lamport, Robert Shostak, and Marshal Pease in March 1980 as a technical report at SRI International. (These authors also wrote a largely similar paper, published in the Journal of the ACM in...