A probabilistic Proof-of-Stake protocol with fast confirmation

【Author】 Dou, Hanyue; Yin, Lingyuan; Lu, Yuan; Xu, Jing

【Source】JOURNAL OF INFORMATION SECURITY AND APPLICATIONS

【Abstract】Proof-of-Stake (PoS) protocol is one of the most promising blockchain consensus protocols in the permissionless setting. However, there is a general problem of slow confirmation in PoS protocol. To address the issue, a small -sized committee in PoS protocol is used to reduce the costs in terms of communication and computation, and accelerate confirmation. Following this idea, a committee-based PoS protocol called LaKSA (NDSS'2021) is proposed recently.In this paper, we present a balance attack on LaKSA, and show LaKSA cannot satisfy the liveness property even in the synchronous network. To ensure security and improve efficiency, we propose a self-healing probabilistic PoS protocol with a small-sized committee and a fast confirmation. Specifically, we propose a three-phase broadcast finality gadget and two compatible confirmation rules. The participants can invoke the three-phase broadcast periodically and commit a block according to different confirmation rules. By our approaches, on the one hand, we can prevent the PoS protocol from the balance attack and keep it committing new blocks over time. On the other hand, it empowers the protocol an ability of self-healing, by which nodes can commit a block as quickly as possible instead of waiting for a long time. Furthermore, we prove that our protocol can achieve the security properties of probabilistic safety and liveness. Finally, we conduct extensive experiments to evaluate the performance of the self-healing protocol. The experimental results show that, compared with LaKSA protocol, our protocol improves the commit rate by about 30% with a high throughput under a poor network condition.

【Keywords】Blockchain; Consensus; Proof-of-Stake

【标题】一种具有快速确认功能的概率性取证协议

【摘要】股权证明（PoS）协议是无权限设置中最有前途的区块链共识协议之一。然而，在PoS协议中存在一个普遍的问题，即确认速度慢。为了解决这个问题，PoS协议中的小规模委员会被用来减少通信和计算方面的成本，并加速确认。根据这个想法，最近提出了一个基于委员会的PoS协议，称为LaKSA（NDSS'2021）。在本文中，我们提出了对LaKSA的平衡攻击，并表明LaKSA即使在同步网络中也不能满足有效性属性。为了确保安全和提高效率，我们提出了一个具有小规模委员会和快速确认的自愈概率PoS协议。具体来说，我们提出了一个三阶段的广播终结机制和两个兼容的确认规则。参与者可以定期调用三阶段广播，并根据不同的确认规则提交一个区块。通过我们的方法，一方面，我们可以防止PoS协议受到平衡攻击，并保持它在一段时间内提交新区块。另一方面，它赋予了协议一种自我修复的能力，通过这种能力，节点可以尽快提交一个区块，而不是等待很长时间。此外，我们证明了我们的协议可以实现概率安全和有效性的安全属性。最后，我们进行了广泛的实验来评估自愈协议的性能。实验结果表明，与LaKSA协议相比，我们的协议提高了约30%的提交率，在恶劣的网络条件下具有较高的吞吐量。

【发表时间】2022

【收录时间】2022-08-30

【文献类型】Article

【论文大主题】共识机制

【论文小主题】POS改进

【影响因子】4.960