Permissionless blockchain technology offers numerous potential benefits for decentralised applications, such as security, transparency, and openness. BFT-based consensus mechanisms are widely adopted in the permissioned blockchain to meet the high scalability requirements of the network. Sybil attacks are one of the most potential threats when applying BFT-based consensus mechanisms in permissionless blockchain due to the lack of effective verification mechanisms for participants' identities. This paper presents a novel endorsement-based bootstrapping protocol with a signature algorithm that offers a streamlined, scalable identity endorsement and verification process. This approach effectively safeguards the BFT-based consensus mechanism against Sybil attacks. Using our proposed method, we have conducted thorough security analyses and simulation experiments to assess security, robustness, and scalability advantages in large-scale networks. Our results demonstrate that the scheme can effectively address the identity verification challenges when applying BFT-based consensus in a permissionless blockchain.

翻译：无许可区块链技术为去中心化应用提供了诸多潜在优势，例如安全性、透明性和开放性。基于拜占庭容错（BFT）的共识机制被广泛采用于许可型区块链，以满足网络对高可扩展性的需求。当将BFT共识机制应用于无许可区块链时，由于缺乏有效的参与者身份验证机制，女巫攻击成为最具威胁性的攻击之一。本文提出了一种新型的基于背书的引导协议，结合签名算法，实现了简化且可扩展的身份背书与验证流程。该方法有效保护了BFT共识机制免受女巫攻击。通过所提出的方案，我们开展了全面的安全分析与仿真实验，评估了大规模网络中的安全性、健壮性和可扩展性优势。实验结果表明，该方案能够有效解决在无许可区块链中应用BFT共识时所面临的身份验证挑战。