[论文解读] PoAh: A Novel Consensus Algorithm for Fast Scalable Private Blockchain for Large-scale IoT Frameworks

Deepak Puthal, Saraju P. Mohanty+2 more|arXiv (Cornell University)|Jan 21, 2020

Blockchain Technology Applications and Security参考文献 6被引用 34

一句话总结

本文提出 PoAh，一种轻量级共识算法，使用基于认证的机制在私有物联网区块链中取代 PoW，通过仿真和 Raspberry Pi 测试床进行验证。

ABSTRACT

In today's connected world, resource constrained devices are deployed for sensing and decision making applications, ranging from smart cities to environmental monitoring. Those recourse constrained devices are connected to create real-time distributed networks popularly known as the Internet of Things (IoT), fog computing and edge computing. The blockchain is gaining a lot of interest in these domains to secure the system by ignoring centralized dependencies, where proof-of-work (PoW) plays a vital role to make the whole security solution decentralized. Due to the resource limitations of the devices, PoW is not suitable for blockchain-based security solutions. This paper presents a novel consensus algorithm called Proof-of-Authentication (PoAh), which introduces a cryptographic authentication mechanism to replace PoW for resource constrained devices, and to make the blockchain application-specific. PoAh is thus suitable for private as well as permissioned blockchains. Further, PoAh not only secures the systems, but also maintains system sustainability and scalability. The proposed consensus algorithm is evaluated theoretically in simulation scenarios, and in real-time hardware testbeds to validate its performance. Finally, PoAh and its integration with the blockchain in the IoT and edge computing scenarios is discussed. The proposed PoAh, while running in limited computer resources (e.g. single-board computing devices like the Raspberry Pi) has a latency in the order of 3 secs.

研究动机与目标

• 在资源受限的物联网与边缘环境中解决区块链的安全性与可扩展性需求。
• 提出一种用密码学认证替代 PoW 的轻量级共识机制。
• 通过仿真和真实硬件测试床验证 PoAh 的可行性与性能。

提出的方法

• 提出 Proof-of-Authentication (PoAh) 作为面向物联网与边缘设备的基于密码学认证的共识。
• 在区块块验证流程中使用 ElGamal 密码学进行签名、MAC 验证和加密。
• 实现基于可信节点的认证流程，以验证并广播经过认证的区块。
• 分配并调整节点信任值，以减轻错误认证并抵抗 51% 攻击。
• 通过基于 Python 的仿真和一个包含 6 个节点的 Raspberry Pi 测试床评估 PoAh 的性能。

实验结果

研究问题

• RQ1 PoAh 是否能在资源受限的物联网设备上提供与 PoW/PoS 相比的安全且快速的区块验证？
• RQ2 PoAh 是否在保持物联网场景区块链安全的同时降低区块验证的能耗和时间成本？
• RQ3 可信节点认证机制如何影响物联网区块链的扩展性和对攻击的鲁棒性？

主要发现

• 仿真结果显示 PoAh 的平均认证时间在 3.34 秒，覆盖 500 次迭代。
• 6 个树莓派设备的硬件测试床证明 PoAh 在实时数据和认证工作流下的运行。
• PoAh 通过以快速的密码学认证替代哈希逆运算的 PoW，降低能耗和时间成本。
• 可信节点在广播前对区块进行认证，解决物联网网络中的不稳定性和 51% 攻击担忧。