As a shared and distributed database, blockchain empowers distributed edge computing (EC) networks with decentralization, integrity, and auditability of trust management. However, a bottleneck issue of blockchain-enabled decentralized trust management (B-DTM) lies in off-chain trust verification, since blockchain is a guarantee of on-chain trustworthiness rather than the reliability of off-chain trust. To orchestrate the off-chain and on-chain trust, we develop a novel B-DTM framework for EC networks that features off-chain trust verification and on-chain trust based consensus mechanisms. In the off-chain environment of EC, each edge node gains its verifiable trust according to Quality of Task Execution (QoTE). Furthermore, we justify that verified off-chain trust can be used as stake for the on-chain consensus. In particular, we design a novel consensus mechanism called Proof-of-Trusted-Work (PoTW), wherein the difficulty adjustable mining work and chain structure of trust data are introduced to promote the on-chain trust security and the trust based mining difficulty adjustment is employed to improve the on-chain trust update efficiency. Simulation results demonstrate the efficiency and security performances of the proposed B-DTM against various on-chain and off-chain malicious attacks.

中文翻译：

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区块链辅助的边缘计算去中心化信任管理：实现可靠的链下和链上信任


区块链作为共享的分布式数据库，赋予分布式边缘计算（EC）网络信任管理的去中心化、完整性和可审计性。然而，基于区块链的去中心化信任管理（B-DTM）的瓶颈问题在于链下信任验证，因为区块链是链上可信性的保证，而不是链下信任的可靠性。为了协调链下和链上信任，我们为 EC 网络开发了一种新颖的 B-DTM 框架，该框架具有链下信任验证和基于链上信任的共识机制。在EC的链下环境中，每个边缘节点根据任务执行质量（QoTE）获得可验证的信任。此外，我们证明经过验证的链下信任可以用作链上共识的权益。特别是，我们设计了一种新颖的共识机制，称为可信工作证明（PoTW），其中引入了难度可调的挖矿工作和信任数据的链结构，以促进链上信任安全和基于信任的挖矿难度调整用于提高链上信任更新效率。仿真结果证明了所提出的 B-DTM 针对各种链上和链下恶意攻击的效率和安全性能。