Self-sovereign identity

Self-sovereign identity (SSI) is an approach to digital identity that gives individuals control over the information they use to prove who they are to websites, services, and applications across the web. Without SSI, individuals with persistent accounts (identities) across the internet must rely on a number of large identity providers, such as Facebook (Facebook Connect) and Google (Google Sign-In), that have control of the information associated with their identity. If a user chooses not to use a large identity provider, then they have to create new accounts with each service provider, which fragments their web experiences. Self-sovereign identity offers a way to avoid these two undesirable alternatives. In a self-sovereign identity system, the user accesses services in a streamlined and secure manner, while maintaining control over the information associated with their identity. SSI systems are commonly built upon Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs). DIDs provide decentralized, cryptographically verifiable identifiers that enable secure authentication without centralized registries, while verifiable credentials allow trusted issuers to attest to specific claims about an identity subject. These credentials can be presented and verified cryptographically, often without direct interaction with the issuer at the time of verification.