Designing Modular Services in the Scattered Byzantine Failure Model

In this paper, we propose the scattered byzantine failure model. Inthis model processes alternate correct and faulty periods.Specifically, during its faulty periods, a process behavesarbitrarily (one cannot expect anything from it during theseperiods) whereas during its correct periods, it behaves accordingto its specification. In that sense, the scattered Byzantinefailure model generalizes the classical Byzantine failure model. Wecharacterize two reliable services guaranteeing timelinessproperties in the presence of Byzantine failures, namely the ClockSynchronization and the /spl delta/-Atomic Broadcast. We identifynecessary and sufficient conditions to ensure the correctness ofboth services in the scattered byzantine failure model.