> Because in order to verify that a hash over some secret data is correct you need access to the secret data, which makes it pointless. No. You could have acce

> Because in order to verify that a hash over some secret data is correct you need access to the secret data, which makes it pointless. No. You could have access to the hash. For the private/public key signing, of course; the signature guarantees that you have access to the private key. But if the ‘private secret data’ is not the private key?