def METHOD_NAME(self):
    """Initialize handler operation."""
    signing_key = Ed25519PrivateKey.from_private_bytes(self.credentials.ltsk)
    verifying_key = signing_key.public_key()
    self._auth_private = signing_key.private_bytes(
        encoding=serialization.Encoding.Raw,
        format=serialization.PrivateFormat.Raw,
        encryption_algorithm=serialization.NoEncryption(),
    )
    self._auth_public = verifying_key.public_bytes(
        encoding=serialization.Encoding.Raw, format=serialization.PublicFormat.Raw
    )
    log_binary(
        _LOGGER,
        "Authentication keys",
        Private=self._auth_private,
        Public=self._auth_public,
    )