Deploying blockchain in IoT is an effective way to address traditional security issues. However, existing approaches have two major limitations: since the blockchain itself is subject to attacks, including selfish mining, double spending, and distributed denial of service attacks, IoT smart devices are also vulnerable once hackers successfully invade blockchain systems; due to the heterogeneity and resource limitations of IoT devices, the deployment of the existing blockchain systems in the IoT scenario cannot reflect strong adaptability and meet IoT service requirements. In this article, we introduce Spacechain, a secure and high-performance blockchain system with three-dimensional ledger architecture, to enable blockchain open in IoT. Specifically, we first design a three-dimensional architecture with novel data structures to deal with the heterogeneity and scalability of IoT networks. Then, we propose the Three-Dimensional Greedy Heaviest-Observed Sub-Tree (3D-GHOST) consensus mechanism for Spacechain to improve security and network performance. Additionally, we conduct detailed security analysis and extensive experimental verification to demonstrate the performance of Spacechain.

中文翻译：

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太空链：用于物联网安全的三维区块链架构

在物联网中部署区块链是解决传统安全问题的有效方法。但是，现有方法有两个主要局限性：由于区块链本身会受到攻击，包括自私的挖矿，双重支出和分布式拒绝服务攻击，因此一旦黑客成功入侵区块链系统，IoT智能设备也很容易受到攻击；由于物联网设备的异构性和资源局限性，物联网场景中现有区块链系统的部署无法反映强大的适应性并不能满足物联网服务需求。在本文中，我们将介绍Spacechain，这是一个具有三维分类帐体系结构的安全，高性能的区块链系统，可实现在IoT中开放区块链。特别，我们首先设计具有新颖数据结构的三维体系结构，以应对物联网网络的异构性和可扩展性。然后，我们提出了针对空间链的三维贪婪最重观测子树（3D-GHOST）共识机制，以提高安全性和网络性能。此外，我们进行了详细的安全性分析和广泛的实验验证，以证明太空链的性能。