Core network equipment (16) is configured for use in a core network of a wireless communication system. The core network equipment (16) is configured to switch switching to using a new non-access stratum, NAS, security context between a user equipment (14) and the core network equipment (16). The core network equipment (16) is also configured to, during or in association with a handover procedure for handover of the user equipment (14), signal from the core network equipment (16) that the new NAS security context between the user equipment (14) and the core network equipment (16) is to be used as a basis for an access stratum (AS) security context between the user equipment (14) and radio access network equipment (12).