论文标题
罗利:具有良性和欺骗性故障的弹性最佳共识协议
Basilic: Resilient Optimal Consensus Protocols With Benign and Deceitful Faults
论文作者
论文摘要
拜占庭共识的问题一直是设计安全分布式系统的关键。但是,这特别困难,主要是由于存在任意行动的拜占庭过程以及一般网络中未知的消息延迟。 尽管众所周知,在$ N/3 $拜占庭流程失败的情况下,安全性和livesice都处于危险之中,但很少有作品试图精确地表征造成违反终止违规的断层的故障,而这些措施都会有效。 在本文中,我们通过区分违反安全性和良性断层的欺骗性断层,违反拜占庭式断层,在我们称为拜占庭 - 达格德·贝尼格(Byzantine-Debenign-Benign)故障模型中违反了安全性和良性断层,从而对共识问题的解决性进行了新的下降。我们表明,如果$ n \ leq 3t+d+2q $带有$ t $ byzantine流程,$ d $欺骗性流程和$ q $ andign流程,则无法解决共识。 此外,我们通过介绍在$ n> 3t+d+2q $时解决共识协议的一类共识协议,通过提出罗利类别的共识协议来表明。这些协议在进步之前等待接收消息的过程数量有所不同。因此,根据良性或欺骗性断层的优势,这些方案中的每一个都更适合某些应用。 最后,我们研究了需要解决最终共识问题较弱问题的区块链中,共识方案的可容忍度。我们证明,罗贝利克仅用$ n> 2t+d+q $解决了这个问题,因此证明了它如何增强区块链安全性。
The problem of Byzantine consensus has been key to designing secure distributed systems. However, it is particularly difficult, mainly due to the presence of Byzantine processes that act arbitrarily and the unknown message delays in general networks. Although it is well known that both safety and liveness are at risk as soon as $n/3$ Byzantine processes fail, very few works attempted to characterize precisely the faults that produce safety violations from the faults that produce termination violations. In this paper, we present a new lower bound on the solvability of the consensus problem by distinguishing deceitful faults violating safety and benign faults violating termination from the more general Byzantine faults, in what we call the Byzantine-deceitful-benign fault model. We show that one cannot solve consensus if $n\leq 3t+d+2q$ with $t$ Byzantine processes, $d$ deceitful processes, and $q$ benign processes. In addition, we show that this bound is tight by presenting the Basilic class of consensus protocols that solve consensus when $n > 3t+d+2q$. These protocols differ in the number of processes from which they wait to receive messages before progressing. Each of these protocols is thus better suited for some applications depending on the predominance of benign or deceitful faults. Finally, we study the fault tolerance of the Basilic class of consensus protocols in the context of blockchains that need to solve the weaker problem of eventual consensus. We demonstrate that Basilic solves this problem with only $n > 2t+d+q$, hence demonstrating how it can strengthen blockchain security.