This is discussed in the intro of the spec: https://www.w3.org/TR/did-core/#introduction https://www.w3.org/TR/did-core/#introduction. My understanding is that

This is discussed in the intro of the spec: https://www.w3.org/TR/did-core/#introduction https://www.w3.org/TR/did-core/#introduction. My understanding is that the DID method can use a "centralized" identity provider like the Mastercard Identity Service (https://github.com/Mastercard/did-methods/blob/master/id.md https://github.com/Mastercard/did-methods/blob/master/id.md), which is presumably backed by some boring database, a decentralized-but-not-blockchain one like IPID which uses IPFS to store and lookup identities (https://did-ipid.github.io/ipid-did-method https://did-ipid.github.io/ipid-did-method), or blockchain-specific ones like ENS. > [Verifiable data registries] include distributed ledgers, decentralized file systems, databases of any kind, peer-to-peer networks, and other forms of trusted data storage.