Some methods in a wireless communication network may include providing a first authentication key, and deriving a second authentication key based on the first authentication key, with the second authentication key being associated with the wireless terminal. Responsive to deriving the second authentication key, a key response message may be transmitted including the second authentication key and/or an EAP-Finish/Re-auth message. Some other methods in a wireless communication network may include receiving a key response message including a core network mobility management authentication key and an EAP-Finish/Re-auth message. Responsive to receiving the key response message, the network may initiate transmission of an EAP-Finish/Re-auth message and/or a freshness parameter used to derive the core network mobility management authentication key from the wireless communication network to the wireless terminal responsive to the key response message. Related wireless terminal methods are also discussed.