One of the most celebrated problems of fault-tolerant distributed computing is the consensus problem. It was shown to abstract a myriad of problems in which processes have to agree on a single value. Consensus applications include fundamental services for the environments of the Cloud or Blockchain. In such challenging environments, malicious behavior is often modeled as adversarial Byzantine faults. At OPODIS 2010, Moste}faoui and Raynal, in short, MR, presented a Byzantine- and intrusion-tolerant solution to consensus in which the decided value cannot be a value proposed only by Byzantine processes. In addition to this validity property, MR has optimal resilience since it can deal with up to t < n/3 Byzantine processes, where n is the number of processes. We note that MR provides this multivalued consensus object (which accepts proposals taken from a set with a finite number of values) assuming the availability of a single Binary consensus object (which accepts proposals taken from the set {0,1}). This work, which focuses on multivalued consensus, aims at the design of an even more robust solution than MR. Our proposal expands MR's fault-model with self-stabilization, a vigorous notion of fault-tolerance. In addition to tolerating Byzantine and communication failures, self-stabilizing systems can automatically recover after the occurrence of arbitrary transient-faults. These faults represent any violation of the assumptions according to which the system was designed to operate (provided that the algorithm code remains intact). To the best of our knowledge, we propose the first self-stabilizing solution for intrusion-tolerant multivalued consensus for asynchronous message-passing systems prone to Byzantine failures.
翻译:最值得庆幸的对错容忍分布式计算问题之一是共识问题。 它被证明抽象了众多的问题, 各个进程必须就单一价值达成一致。 共识应用包括了云层或链链环境的基本服务。 在这种富有挑战性的环境中, 恶意行为往往以对抗的拜占庭断层为模范。 在 OPODIS 2010, Moste}faoui 和 Raynal, 简而言之, MR 提供了一种Byzantine 和入侵容忍性解决方案, 其中确定的价值不能成为仅由Byzantine进程提出的价值。 除了这一有效性属性外, MR拥有最佳的复原力, 因为它可以处理到 < / 3/ 3 Byzantine 进程环境的基本服务。 在这种具有挑战性的环境中, 恶意行为往往被模拟为Byzantine 断层的共识。 我们的提议是,MR的自我稳定度假设是自我稳定化的自我恢复。