diff --git a/homeassistant/backup_restore.py b/homeassistant/backup_restore.py
index c42cc900a7b0df..24ad411ec91911 100644
--- a/homeassistant/backup_restore.py
+++ b/homeassistant/backup_restore.py
@@ -28,10 +28,8 @@ class RestoreBackupFileContent:
     password: str | None = None
 
 
-def password_to_key(password: str | None) -> bytes | None:
+def password_to_key(password: str) -> bytes:
     """Generate a AES Key from password."""
-    if password is None:
-        return None
     key: bytes = password.encode()
     for _ in range(100):
         key = hashlib.sha256(key).digest()
@@ -105,7 +103,7 @@ def _extract_backup(
                 f"homeassistant.tar{'.gz' if backup_meta["compressed"] else ''}",
             ),
             gzip=backup_meta["compressed"],
-            key=password_to_key(password),
+            key=password_to_key(password) if password is not None else None,
             mode="r",
         ) as istf:
             istf.extractall(
diff --git a/homeassistant/components/backup/manager.py b/homeassistant/components/backup/manager.py
index 1734194cb79cd1..59b621957524e7 100644
--- a/homeassistant/components/backup/manager.py
+++ b/homeassistant/components/backup/manager.py
@@ -129,6 +129,7 @@ async def load_platforms(self) -> None:
     async def async_restore_backup(
         self,
         slug: str,
+        *,
         password: str | None = None,
         **kwargs: Any,
     ) -> None:
@@ -137,6 +138,7 @@ async def async_restore_backup(
     @abc.abstractmethod
     async def async_create_backup(
         self,
+        *,
         password: str | None = None,
         **kwargs: Any,
     ) -> Backup:
@@ -235,6 +237,7 @@ async def async_remove_backup(self, *, slug: str, **kwargs: Any) -> None:
 
     async def async_create_backup(
         self,
+        *,
         password: str | None = None,
         **kwargs: Any,
     ) -> Backup:
@@ -308,7 +311,7 @@ def _mkdir_and_generate_backup_contents(
             with outer_secure_tarfile.create_inner_tar(
                 "./homeassistant.tar.gz",
                 gzip=True,
-                key=password_to_key(password=password),
+                key=password_to_key(password) if password is not None else None,
             ) as core_tar:
                 atomic_contents_add(
                     tar_file=core_tar,
@@ -321,6 +324,7 @@ def _mkdir_and_generate_backup_contents(
     async def async_restore_backup(
         self,
         slug: str,
+        *,
         password: str | None = None,
         **kwargs: Any,
     ) -> None:
diff --git a/tests/test_backup_restore.py b/tests/test_backup_restore.py
index e5b6dfbfba5e0e..7f69d4db728a96 100644
--- a/tests/test_backup_restore.py
+++ b/tests/test_backup_restore.py
@@ -236,7 +236,6 @@ def _patched_path_read_text(path: Path, **kwargs):
 @pytest.mark.parametrize(
     ("password", "expected"),
     [
-        (None, None),
         ("test", b"\xf0\x9b\xb9\x1f\xdc,\xff\xd5x\xd6\xd6\x8fz\x19.\x0f"),
         ("lorem ipsum...", b"#\xe0\xfc\xe0\xdb?_\x1f,$\rQ\xf4\xf5\xd8\xfb"),
     ],
@@ -244,3 +243,17 @@ def _patched_path_read_text(path: Path, **kwargs):
 def test_pw_to_key(password: str | None, expected: bytes | None) -> None:
     """Test password to key conversion."""
     assert backup_restore.password_to_key(password) == expected
+
+
+@pytest.mark.parametrize(
+    ("password", "expected"),
+    [
+        (None, None),
+        ("test", b"\xf0\x9b\xb9\x1f\xdc,\xff\xd5x\xd6\xd6\x8fz\x19.\x0f"),
+        ("lorem ipsum...", b"#\xe0\xfc\xe0\xdb?_\x1f,$\rQ\xf4\xf5\xd8\xfb"),
+    ],
+)
+def test_pw_to_key_none(password: str | None, expected: bytes | None) -> None:
+    """Test password to key conversion."""
+    with pytest.raises(AttributeError):
+        backup_restore.password_to_key(None)