Is it necessary to pass a ECDH generated key to a KDF?
According to the python cryptography documentation, it is stated that
For most applications the shared_key should be passed to a key derivation function. This allows mixing of additional information into the key, derivation of multiple keys, and destroys any structure that may be present.
On a side note, isn't a KDF used to generated multiple keys of desired length?
How does it achieve this if if only produces a single key of variable length?
EDIT: The main point here is I would like to know why we should pass a ECDH key into a KDF.