Cryptography
Ed25519
Also known as: EdDSA Ed25519
An EdDSA signature scheme over the Curve25519 twist — faster than secp256k1 ECDSA, with deterministic nonces built in.
Ed25519 is a variant of EdDSA (Edwards-curve Digital Signature Algorithm) over Curve25519 (Ed25519 curve). It was designed by Bernstein, Duif, Lange, Schwabe, and Yang in 2011 with explicit goals that ECDSA doesn't meet out of the box: deterministic signatures (no nonce-reuse attack), constant-time implementations (no timing side-channels), and better default performance.
Ed25519 is the curve the W3C VC ecosystem has largely standardized on for non-Ethereum contexts. The DID document spec includes Ed25519VerificationKey2020 as a canonical verification method type. Blockcerts + Ethereum anchoring pushed LearnCoin toward secp256k1, but Ed25519 is the better cryptographic choice for contexts not bound to Ethereum's native signature scheme.
Future LearnCoin work — specifically OpenID4VCI and EUDI Wallet alignment — may introduce Ed25519 alongside secp256k1 for credentials that don't need to settle on an EVM chain. The DID document would then declare both key types, and credentials would pick the appropriate verificationMethod based on use case.
Related terms