Notes: Keys are calculated localy via javascript and not published!
The ed25519 curve generates a primary key for signing using Ed25519 and a subkey for encryption using Curve25519.
More info can be found on Wikipedia EdDSACurve25519
You don't have to set a passphrase. if you don't, anyone who owns a copy of your private key can use it!
Setting a long secure password (20-30 characters) enhances security.