Definition
Self-Sovereign Identity (SSI) is an approach to digital identity in which the individual, not a platform, a government, or a corporation, is the ultimate custodian of their identity data. Rather than logging in through Google or a national ID provider, the person holds cryptographic keys and credentials in a wallet they control, and discloses only what a given interaction requires. The idea echoes the Bitcoiner's principle of self-custody: you hold the keys, so no third party can lock you out or surveil every use.
The ten guiding principles
In his 2016 essay "The Path to Self-Sovereign Identity," Christopher Allen proposed ten principles that the SSI community still treats as a starting point: existence, control, access, transparency, persistence, portability, interoperability, consent, minimization, and protection of the user's rights. Together they describe an identity that survives any single provider, travels with the user, and shares no more data than strictly needed.
How the pieces fit
SSI is realized through two underlying technologies. Decentralized Identifiers give the user a self-controlled, registry-independent identifier, and Verifiable Credentials let trusted issuers attest to claims about that identifier. The wallet ties them together so the holder can present proofs offline and selectively.
SSI sits alongside other sovereignty practices we document, including end-to-end encryption and tooling like Keyoxide for decentralized identity proofs.
In Simple Terms
Self-Sovereign Identity (SSI) is an approach to digital identity in which the individual, not a platform, a government, or a corporation, is the ultimate custodian…