ed25519 and sha256

[Robert Hübener]

Hello,

I have a question regarding ed25519 as implemented in gnupg 2.2.17, libgcrypt 1.8.4.

Let’s say I sign a file. When checking the signature with verbose output, I can see that sha256 was used

gpg: binary signature, digest algorithm SHA256, key algorithm ed25519

According to Wikipedia "Ed25519 is the EdDSA signature scheme using SHA-512 and Curve25519”. Granted, I have sha256 in my preferences, but the standard should override that, correct? I wonder, because in a different application (iPGMail) using the same key with the same embedded preferences, sha512 is used.

Curious,
RH