Section: 6.9.6 Security handling in registration with AMF reallocation via direct NAS reroute
Content: In registration with AMF reallocation via direct NAS reroute, the initial AMF shall send the complete Registration Request in clear text to the target AMF. NOTE: The completeRegistration Request in clear text is obtained based on the Registration Request initially received by the initial AMF if the UE have a valid NAS sececurity context, or the Registration Request received by the initial AMF as part of the Security Mode Complete if it is executed. In registration with AMF reallocation via direct NAS reroute, the initial AMF shall use its local policy to determine whether to perform horizontal KAMF derivation on current KAMF. As described in Clause 6.9.3, if the initial AMF decides not to change KAMF, the initial AMF shall send the current security context to the target AMF; otherwise, the initial AMF shall derive new security context and send to the target AMF the derived security context and the indication of horizontal KAMF derivation (i.e., keyAmfHDerivationInd). If the target AMF receives the indication of horizontal KAMF derivation (i.e., keyAmfHDerivationInd) from the initial AMF, it shall initiate NAS SMC. If the target AMF does not receive keyAmfHDerivationInd, the target AMF shall use the received security context from initial AMF and send protected NAS message including protected authentication request message if authentication is needed. The target AMF decides whether to perform authentication based on local policy.