【作者】 孙毅；

【导师】 许昱玮； 秦益飞；

【作者基本信息】 东南大学 ， 网络与信息安全（专业学位）， 2024， 硕士

【摘要】 区块链以其去中心化、可追溯性等特点,在传统行业的数字化转型中发挥着巨大的作用。随着区块链应用市场化进程的推进,区块链行业面临的监管问题日益凸显,对政府机构的监管方式和技术提出了新的挑战。针对传统集中监管模式破坏了区块链的去中心化特性问题,当前研究提出使用跨链技术来实现一条区块链监管多条区块链的分布式监管模式,称为“以链治链”。然而,目前主流的跨链技术难以同时满足分布式监管的跨链访问高效、数据安全传输的需求。对此,通过高性能的物理主机搭建共享节点同时加入监管链和业务链,使跨链双方在主机内进行数据交互,从而实现高效、安全的跨链监管是一条可行的思路。然而,目前尚缺乏对基于共享节点的跨链监管方法的相关研究。此外,基于共享节点的跨链监管方法面临着以下三个技术挑战:一是如何在保证跨链交互高效性的同时避免共享节点的安全风险;二是在构建以共享节点作为跨链载体的过程中如何平衡共享节点的可靠性和性能负担问题;三是缺乏满足跨链监管需求的系统。针对上述问题,本文在“以链治链”跨链监管场景下开展基于共享节点的区块链跨链监管方法研究,主要工作的贡献在于以下三点:(1)针对当前跨链监管方法未能兼顾“以链治链”高效性与安全性的问题,本文提出了基于共享节点的跨链监管方案。首先,设计了一种基于共享节点的分层跨链监管架构,监管链与业务链之间通过部署共享节点实现跨链高效交互,减少通信开销;通过设计多通道异步并行机制,共享节点能够同时处理多个跨链请求,大幅提升监管活动的处理效率。其次,设计了一个三阶段跨链监管交互协议,在准备阶段设计基于VRF的节点验证方法,确保节点选取的合法性;在跨链阶段设计基于代理重加密的跨链监管数据传输方法来保证链间交互的安全性;在提交阶段通过多通道验证及审计追溯机制来确保监管数据的真实可靠性。最后,通过理论分析证明了本方案可以有效应对“以链治链”中的安全挑战,并具有良好的跨链监管效率。(2)针对跨链监管场景中共享节点的可靠性和性能负担难以平衡的问题,本文提出了一种基于信誉的共享节点均衡选择方法。一方面,根据共享节点在跨链监管活动中返回的数据结果以及处理时间改进Beta信誉模型的奖惩机制,并引入作恶因子来抑制共享节点的恶意行为和自私行为。另一方面,通过设计一个综合考虑共享节点信誉值、参与情况和负载情况的排序算法来优化节点选择过程,防止高信誉节点负载过重,从而提高跨链效率。最后,本文通过理论分析和仿真实验验证了所提方法能够有效抑制恶意行为和自私行为,在保障所选节点可靠性的同时提高跨链监管的效率。(3)针对“以链治链”跨链监管模式的不同角色用户需求,本文搭建了一个基于共享节点的跨链监管系统。首先,根据系统用户的实际需求提炼了系统所需的查询、跨链监管功能。其次,在系统的总体架构设计中,将跨链监管活动和其中的共享节点选择任务抽象为交易,并针对交易结构设计了智能合约保证跨链监管活动的可追溯性以及保证节点选择过程中各项计算的正确性。最后,通过搭建Web可视化界面满足用户操作需求,并通过环境测试证明所设计系统具有高吞吐量和低延迟,满足“以链治链”跨链监管的需求。更多还原

【Abstract】 Blockchain,with its characteristics of decentralization and traceability,plays an important role in the digital transformation of traditional industries.The marketization of blockchain applications is increasing.This poses challenges to the government in terms of supervision and technology.Researchers have created methods using cross-chain technology to address the problem of centralized supervision affecting the decentralized nature of blockchain.This model allows one blockchain to supervise multiple blockchains,known as”chain-supervising-chain”.However,the current mainstream cross-chain technology cannot simultaneously satisfy the needs of efficient cross-chain access and secure data transmission.Through shared nodes using high-performance physical hosts and connecting both the supervision and business chains,allows for data exchange between different parties across chains.This achieves efficient and secure cross-chain supervision.However,there is still a lack of relevant research on cross-chain supervision methods through shared nodes.In addition,cross-chain supervision based on shared nodes will face three technical challenges:1)ensuring security while maintaining efficiency;2)balancing reliability and performance of shared nodes;3)lack of system to meet cross-chain supervision needs.In response,this thesis researches the cross-chain supervision method through shared nodes in the”chain-supervising-chain”scenario.The contributions of this work lie in the following three points:(1)Aiming at the problem that the current cross-chain supervision method fails to balance the efficiency and security of requirements of”chain-supervising-chain”,this thesis proposes a cross-chain supervision scheme based on shared nodes.First,a hierarchical cross-chain super-vision architecture based on shared nodes is designed.Supervision and business chains utilize shared nodes to facilitate interaction within the network and minimize communication overhead.A multi-bridge asynchronous parallel mechanism is used to efficiently process cross-chain su-pervision requests.This allows shared nodes to handle multiple cross-chain requests simultane-ously,improving efficiency significantly in handling supervision activities.Secondly,a three-phase cross-chain supervision protocol is designed.During the preparation phase,a method is designed using VRF to verify nodes and establish the credibility of the node selection.In the cross-chain phase,proxy re-encryption is used to secure the interactions between different blockchains.During the submission phase,use mechanisms such as multi-bridge verification and audit traceability to ensure that the supervision data is authentic and reliable.Finally,this thesis provides theoretical analysis to show that the scheme can effectively address security challenges in the”chain-supervising-chain”,and confirm that it has efficient cross-chain super-vision.(2)Aiming at the problem that current research fails to balance the reliability and per-formance burden of shared nodes in cross-chain supervision scenarios,this thesis proposes a balanced selection method of shared nodes based on reputation.On the one hand,introducing an enhanced Beta reputation model based on data results and processing time from shared nodes in cross-chain supervision activities.The model includes measures to suppress the malicious and selfish behaviors of the shared nodes by considering malevolent factors.A sorting algo-rithm is used to optimize the node selection process.This algorithm takes into consideration the reputation value,participation,and load of shared nodes.The goal is to improve cross-chain efficiency and avoid overloading high-reputation nodes.This thesis shows that the proposed method is effective at curbing malicious and selfish behaviors,ensuring the reliability of se-lected nodes,and improving cross-chain supervision efficiency.(3)Aiming at meeting the needs of different users in the”chain-supervising-chain”cross-chain supervision model,this thesis constructs a cross-chain supervision system based on shared nodes.Firstly,the essential query and cross-chain supervision functionalities are systematically identified and distilled from the requirements of system users.Secondly,the system architecture is designed to include cross-chain supervision and shared node selection as transactions.Smart contracts ensure the traceability of supervision activities and the accuracy of calculations in the node selection process.Finally,a web visual interface is built to meet user operation needs,and environmental testing proves that the designed system has high throughput and low latency,meeting the needs of cross-chain supervision of”chain-supervising-chain.”更多还原