QUALCOMM Incorporated
Security key derivation for handover

Abstract:

Methods, systems, and devices for wireless communication are described that support security key derivation for handover. A network entity (e.g., an access and mobility function (AMF)) may establish an access stratum (AS) key to ensure secure communications between a user equipment (UE) and a base station. If the UE relocates to a new network entity (e.g., target network entity), the initial network entity (e.g., source network entity) may perform a handover procedure to the target network entity. In some aspects, the network entities may derive a unified AS key for the handover procedure. Additionally, the network entities may utilize one or more intermediate keys (e.g., refreshed intermediate keys) derived from, in part, respective freshness parameters for the handover procedure. The target network entity may then utilize the derived intermediate keys to derive the AS key for the handover procedure and establish communications with the UE.