## 1 Introduction
Because avatars may take on the appearance and actions of other users, and because real people are not always predictable, building trust between users is the primary concern [9; 14]. The emergence of new technologies is frequently swiftly followed by cybersecurity solutions or a set of established guidelines or best practices for developers. However, this is not the case with the entrance of the Metaverse, and in a time when cyberattacks have dramatically increased, it is crucial to look into any potential security flaws. In the Metaverse, trust is considered essential for achieving one's goals. Indeed, there may be a number of challenges to a reliable system supply posed by the core characteristics of the Metaverse, including interoperability, decentralization, immersiveness, and scalability [7]. In recent years, there has been a paradigm shift in digital identity management with the introduction of innovative technologies such as Self-Sovereign Identity (SSI). SSI offers individuals greater autonomy and control over their personal data by enabling them to manage their identities independently of centralized authorities. Additionally, decentralized identifier (DID) technology has emerged as a key component of SSI, providing a method for creating globally unique identifiers that are cryptographically verifiable and under the control of the individual. The majority of new technologies typically have the same security flaws as their predecessors while also creating opportunities for new kinds of attacks. The structure of the Metaverse is not an exception; its structure makes it vulnerable to unusual and more sophisticated attacks. How users' identities, data, and avatars may be shared across different Metaverse virtual worlds is an important concern. Users can easily go to other Metaverse virtual worlds and transfer their data and assets to anywhere they choose. The user's data, avatars, and identity might be restricted to a single virtual service provider (VSP) if there is an incompatible collection of virtual worlds. Concerns about security and privacy will not only increase but also fundamentally change. There has been little research on the security implications of the Metaverse; concerns like how vulnerable this new technology is have not been adequately studied, and if they have, the answers are scarce. This paper's key contributions can be outlined as:  
1. This article investigates the security and privacy concerns prevalent in the Metaverse, with a particular focus on the limitations and challenges of existing centralized identity systems and certificate-based authentication methods. 2. We explore the concept of SSI and its potential applications, highlighting its advantages over traditional identity systems, and propose a novel SSI-based authentication mechanism for the Metaverse, named MetaSSI, designed to enhance user control and interoperability. 3. We demonstrate the practicality and effectiveness of MetaSSI through rigorous proof of work and mathematical formulation. Finally, we propose a comparative analysis of the existing authentication methods and our proposed SSI model against standard SSI evaluation frameworks, validating the superiority of MetaSSI. Section 2 introduces the components of SSI and the key role of SSI in the Metaverse. We offer a concise overview of cyber security challenges, user privacy, and identity management within the Metaverse in Section 3. Section 4 explores additional requirements for implementation and the proposed solutions. An evaluation and results are presented in Section 5. Finally, in Section 6, we wrap up and provide a glimpse into future directions for this work.