Digital identity is evolving from centralized systems to a decentralized approach known as Self-Sovereign Identity (SSI). SSI empowers individuals to control their digital identities, eliminating reliance on third-party data custodians and reducing the risk of data breaches. However, the concept of trust in SSI remains complex and fragmented. This paper systematically analyzes trust in SSI in light of its components and threats posed by various actors in the system. As a result, we derive three distinct trust models that capture the threats and mitigations identified across SSI literature and implementations. Our work provides a foundational framework for future SSI research and development, including a comprehensive catalogue of SSI components and design requirements for trust, shortcomings in existing SSI systems and areas for further exploration.

翻译：数字身份正从中心化系统演变为一种去中心化方法，即自权身份。SSI使个人能够控制自己的数字身份，消除了对第三方数据托管方的依赖，并降低了数据泄露的风险。然而，SSI中的信任概念仍然复杂且碎片化。本文基于SSI的组成部分以及系统中各类参与者构成的威胁，系统性地分析了SSI中的信任问题。由此，我们推导出三种不同的信任模型，这些模型捕捉了SSI文献和实现中已识别的威胁及缓解措施。我们的工作为未来SSI的研究与开发提供了基础框架，包括一份全面的SSI组件目录、信任的设计要求、现有SSI系统的缺陷以及需要进一步探索的领域。