Consensus protocols play a crucial role in determining the security and performance of blockchain systems, with committee-based consensus protocols being particularly important, especially in sharding consensus protocols. Anonymous election of committee nodes can mitigate DDoS attacks and bribery attempts. This approach can also be applied to sharding systems to mitigate the risk associated with a single vulnerable shard. However, current node secret selection schemes still present remaining issues. Single secret leader election schemes struggle to elect multiple leaders with equal anonymity, and existing secret committee election schemes lack adequate measures for tracking malicious nodes. To address these issues, we propose accountable secret committee election schemes that not only regulate the number of nodes but also maintain anonymity during the phases of leader proposal and verifier voting. Furthermore, our schemes enable the tracing of malicious nodes in a threshold way. In addition, we introduce two efficient threshold traceable membership proof schemes for both ad hoc and interactive scenarios. Unlike traceable ring signatures, our scheme can trace malicious nodes even after a single malicious behavior. Subsequently, we apply the accountable secret committee election scheme to sharding blockchains and devise a fully accountable anonymous consensus protocol. The experiment demonstrates that this protocol can elevate the difficulty of corrupting a single shard to the level of compromising the entire system, thereby significantly enhancing the security of the sharding system.

中文翻译：

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问责秘密委员会选举与匿名分片区块链共识


共识协议在确定区块链系统的安全性和性能方面发挥着至关重要的作用，其中基于委员会的共识协议尤其重要，尤其是在分片共识协议中。委员会节点的匿名选举可以减轻 DDoS 攻击和贿赂企图。这种方法也可以应用于分片系统，以减轻与单个易受攻击的分片相关的风险。然而，当前的节点秘密选择方案仍然存在遗留问题。单一秘密领导人选举方案很难选举出多个具有同等匿名性的领导人，而现有的秘密委员会选举方案缺乏足够的措施来跟踪恶意节点。为了解决这些问题，我们提出了负责任的秘密委员会选举方案，该方案不仅可以调节节点数量，而且可以在领导者提议和验证者投票阶段保持匿名。此外，我们的方案能够以阈值方式跟踪恶意节点。此外，我们还为临时场景和交互式场景引入了两种有效的阈值可追踪成员身份证明方案。与可追踪环签名不同，我们的方案即使在单个恶意行为之后也可以追踪恶意节点。随后，我们将负责任的秘密委员会选举方案应用于分片区块链，并设计了一个完全负责任的匿名共识协议。实验表明，该协议可以将破坏单个分片的难度提升到破坏整个系统的程度，从而显着增强分片系统的安全性。