diff --git a/tuf/api/metadata.py b/tuf/api/metadata.py
index 50a6c31845..24cc80790d 100644
--- a/tuf/api/metadata.py
+++ b/tuf/api/metadata.py
@@ -424,8 +424,9 @@ def __init__(
         keyval: Dict[str, str],
         unrecognized_fields: Optional[Mapping[str, Any]] = None,
     ) -> None:
-        val = keyval["public"]
-        if not all(isinstance(at, str) for at in [keyid, keytype, scheme, val]):
+        if not all(
+            isinstance(at, str) for at in [keyid, keytype, scheme]
+        ) or not isinstance(keyval, Dict):
             raise ValueError("Unexpected Key attributes types!")
         self.keyid = keyid
         self.keytype = keytype