In case of horizontal handover UE is moved from one cell to another cell But with in the same ENB. So in this case how the security is activated and how key derived ?
In horizontal key derivation KeNB* key is generated using the KDF (using HMAC-SHA256 algorithm). The input would be current KeNB key and the NCC value would be incremented upon generation of KeNB* and the NCC value is send across UE. The KeNB* would be used as KeNB key.
During the Handover from LTE to WiFi, how an UE is authenticated at WiFi network ? Is there any difference in authentication procedure when UE is handed over to un-trusted or trusted WiFi network ?