What is Self-Sovereign Identity

Self-sovereign identity (SSID) is a digital solution intended to ameliorate the drawbacks associated with existing digital identification management approaches. This chapter begins with an overview of identity management systems. It explores the essential elements of SSID, including verifiable credentials, distributed ledger technology (DLT), and privacy engineering protocols, and highlights research initiatives, governmental projects, and regulatory frameworks that leverage evolving technologies to improve data integrity, efficiency, and security. The authors survey key challenges and advantages associated with SSID, establishing a taxonomy of the SSID model and a summary of privacy engineering techniques that work in concert with SSID, including zero knowledge proofs (ZKPs) and bring your own identity (BYOI) systems. The authors highlight several innovators in the SSID ecosystem that are contributing to the growth and maturity of this model.