Metaverse, as an evolving paradigm of the next-generation Internet, aims to build a fully immersive, hyper spatiotemporal, and self-sustaining virtual shared space for humans to play, work, and socialize. Driven by recent advances in emerging technologies such as extended reality, artificial intelligence, and blockchain, metaverse is stepping from science fiction to an upcoming reality. However, severe privacy invasions and security breaches (inherited from underlying technologies or emerged in the new digital ecology) of metaverse can impede its wide deployment. At the same time, a series of fundamental challenges (e.g., scalability and interoperability) can arise in metaverse security provisioning owing to the intrinsic characteristics of metaverse, such as immersive realism, hyper spatiotemporality, sustainability, and heterogeneity. In this paper, we present a comprehensive survey of the fundamentals, security, and privacy of metaverse. Specifically, we first investigate a novel distributed metaverse architecture and its key characteristics with ternary-world interactions. Then, we discuss the security and privacy threats, present the critical challenges of metaverse systems, and review the state-of-the-art countermeasures. Finally, we draw open research directions for building future metaverse systems.

翻译：作为下一代互联网不断发展的范例,我们的目标是建立一个完全沉浸、超超时空和自我维持的虚拟共享空间,供人类玩耍、工作和社会化。在诸如扩大现实、人工智能和链条等新兴技术的最新进步的驱动下,元正正从科幻小说走向即将到来的现实情况。然而,严重的隐私侵犯和安全侵犯(源于基础技术或在新的数字生态中出现)会阻碍其广泛应用。与此同时,一系列基本挑战(如可伸缩性和互操作性)可能会在不断变化的安全提供中出现。随后,我们讨论安全和隐私威胁,提出未来研究系统、我们研究系统、我们研究系统、我们研究系统、我们研究系统的最后方向、我们研究的现代系统、我们研究的现代系统的最后方向、我们研究的现代审查。