  Self-sovereign identity is the next evolution of identity management models.
This survey takes a journey through the origin of identity, defining digital
identity and progressive iterations of digital identity models leading up to
self-sovereign identity. It then states the relevant research initiatives,
platforms, projects, and regulatory frameworks, as well as the building blocks
including decentralized identifiers, verifiable credentials, distributed
ledger, and various privacy engineering protocols. Finally, the survey provides
an overview of the key challenges and research opportunities around
self-sovereign identity.
