move KDF interface
diff --git a/docs/hazmat/primitives/interfaces.rst b/docs/hazmat/primitives/interfaces.rst
index 6029d1a..f58d324 100644
--- a/docs/hazmat/primitives/interfaces.rst
+++ b/docs/hazmat/primitives/interfaces.rst
@@ -47,46 +47,8 @@
Key derivation functions
------------------------
-.. class:: KeyDerivationFunction
-
- .. versionadded:: 0.2
-
- .. method:: derive(key_material)
-
- :param bytes key_material: The input key material. Depending on what
- key derivation function you are using this
- could be either random bytes, or a user
- supplied password.
- :return: The new key.
- :raises cryptography.exceptions.AlreadyFinalized: This is raised when
- :meth:`derive` or
- :meth:`verify` is
- called more than
- once.
-
- This generates and returns a new key from the supplied key material.
-
- .. method:: verify(key_material, expected_key)
-
- :param bytes key_material: The input key material. This is the same as
- ``key_material`` in :meth:`derive`.
- :param bytes expected_key: The expected result of deriving a new key,
- this is the same as the return value of
- :meth:`derive`.
- :raises cryptography.exceptions.InvalidKey: This is raised when the
- derived key does not match
- the expected key.
- :raises cryptography.exceptions.AlreadyFinalized: This is raised when
- :meth:`derive` or
- :meth:`verify` is
- called more than
- once.
-
- This checks whether deriving a new key from the supplied
- ``key_material`` generates the same key as the ``expected_key``, and
- raises an exception if they do not match. This can be used for
- something like checking whether a user's password attempt matches the
- stored derived key.
+In 0.8 the key derivation function interface was moved to the
+:mod:`cryptography.hazmat.primitives.kdf` module.
`Message Authentication Code`_