Recently, permissioned blockchain has been extensively explored in various fields, such as asset management, supply chain, healthcare, and many others. Many scholars are dedicated to improving its verifiability, scalability, and performance based on sharding techniques, including grouping nodes and handling cross-shard transactions. However, they ignore the node vulnerability problem, i.e., there is no guarantee that nodes will not be maliciously controlled throughout their life cycle. Facing this challenge, we propose RecAGT, a novel identification scheme aimed at reducing communication overhead and identifying potential malicious nodes. First, shard testable codes are designed to encode the original data in case of a leak of confidential data. Second, a new identity proof protocol is presented as evidence against malicious behavior. Finally, adaptive group testing is chosen to identify malicious nodes. Notably, our work focuses on the internal operation within the committee and can thus be applied to any sharding permissioned blockchains. Simulation results show that our proposed scheme can effectively identify malicious nodes with low communication and computational costs.

翻译：近年来，许可区块链在资产管理、供应链、医疗健康等多个领域得到广泛探索。众多学者致力于基于分片技术（包括节点分组与跨分片事务处理）提升其可验证性、可扩展性与性能。然而，现有研究忽略了节点脆弱性问题，即无法保证节点在整个生命周期中不被恶意控制。针对这一挑战，我们提出RecAGT——一种旨在降低通信开销并识别潜在恶意节点的新型识别方案。首先，设计分片可测试码对原始数据进行编码，以防机密数据泄露；其次，提出一种新型身份证明协议作为恶意行为的证据；最后，采用自适应分组测试识别恶意节点。值得注意的是，本工作聚焦委员会内部操作，因此可适用于任何分片许可区块链。仿真结果表明，所提方案能以较低通信与计算开销有效识别恶意节点。