The real Byzantine Generals

In contrast to previous papers on the Byzantine Generals problem, this work examines the problem from a practical, lower-level, phenomena point of view. The goal is to dispel a common belief that the problem is a myth (potentially arising from the anthropomorphic nature of previous literature). This work gives practical, succinct definitions for Byzantine fault and failure. It describes how these arise and are propagated in electrical signals and "digital" circuitry. The paper describes actual occurrences of Byzantine faults in several different systems. A taxonomy of methods for combating the problem is presented with examples of each method. The paper brings forth the following underappreciated facts: (1) cryptography is not a useful solution to the problem in actual systems, (2) most solutions to the problem must include a "Byzantine filter" (a circuit that converts a Byzantine signal to a nonByzantine signal).