发表机构
University of Sydney; Redbelly Network（悉尼大学; 红 Belly 网络）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出STAKE协议，通过质押机制将诚实节点需求降至n/3+1，并证明其达到(k,t)-稳健均衡，防止共谋多数进行双重支付。
AI 中文摘要
区块链通常在开放网络中运行，在这种网络中难以控制消息的延迟。虽然经典的区块链协议假设同步性，但较新的协议试图在意外网络延迟的情况下保持安全性。不幸的是，在传统的模型中，$n$ 个参与者可以是诚实的或拜占庭式的，我们需要其中超多数，即 $\lfloor 2n/3\rfloor + 1$ 个参与者是诚实的。最近的工作探讨了在博弈论模型中通过引入 $k$ 个理性参与者和 $t$ 个拜占庭式参与者，将所需诚实节点数量减少到多数的可能性。然而，据我们所知，没有区块链协议能够进一步减少这一数量。在本文中，我们提出了一种名为通过（$k,t$）-稳健均衡的安全与容忍算法（STAKE）的区块链协议，该协议仅需 $\floor n/3\rfloor + 1$ 个诚实参与者即可运行。STAKE 要求每个共识参与者相对于其流动性 $\ell$ 质押足够大的金额 $s$。我们证明，一个联盟成功执行 $\zeta$ 次双重支付攻击（我们称之为 $\zeta$ 重攻击）的概率随 $\zeta$ 的增加呈多项式速度下降。这使得我们能够证明，即使 $s/\ell$ 比率相对较低，STAKE 也能达到（$k,t$）-稳健均衡，即理性参与者不会与拜占庭式参与者共谋。
英文摘要
Blockchains typically operate in open networks where it is hard to control the delay of messages. While classic blockchain protocols assumed synchrony, newer protocols try to remain secure despite unexpected network delays. Unfortunately, in the traditional model where $n$ participants can either be honest or Byzantine, we need a supermajority, or $\lfloor 2n/3\rfloor + 1$, of them to be honest. Recent work have explored the question of reducing the number of needed honest nodes in a game theory model to a majority sometimes by introducing $k$ rational players and $t$ Byzantine players. Yet, to our knowledge, no blockchain protocol managed to reduce it further. In this paper, we offer a blockchain protocol called Secure and Tolerant Algorithm through ($k,t$)-robust Equilibrium (STAKE) that works with only $\lfloor n/3\rfloor + 1$ honest players. STAKE requires each consensus participant to stake a sufficiently large amount $s$ compared to their liquidity $\ell$. We show that the probability that a coalition manages to execute $ζ$ double spending attacks (we call them a $ζ$-uple attack) drops polynomially fast with $ζ$. This allows us to demonstrate that STAKE reaches a ($k,t$)-robust equilibrium, or that rational players do not collude with Byzantine, even with a relatively low $s/\ell$ ratio.
