Consensus When All Processes May Be Byzantine for Some Time

Among all classes of faults, Byzantine faults form the most general modeling of value faults. Traditionally, in the Byzantine fault model, faults are statically attributed to a set of up to t processes. This, however, implies that in this model a process at which a value fault occurs is forever “stigmatized” as being Byzantine, an assumption that might not be acceptable for long-lived systems, where processes need to be reintegrated after a fault. We thus consider a model where Byzantine processes can recover in a predefined recovery state, and show that consensus can be solved in such a model.