An apparatus, comprising a memory unit; and a control unit connected to the memory unit, the apparatus being configured as a functional unit of a network mobility entity to interface at least one access node (2; 3), wherein the control unit is configured to process one or more higher level security keys received from a network entity to derive at least one local level security key within an established security context for a terminal, forward said derived at least one local level security key to the at least one access node (2; 3), and invoke a context modification procedure to re-adjust the at least one local level security key with at least one local level security key maintained at the terminal within the established security context, wherein a re-keying procedure for the at least one access node (2; 3) is performed in which a network access stratum security mode command procedure is initiated, and an updated network access stratum count parameter of a most recent network access stratum security mode command message is obtained, with the updated network access stratum parameter being used to derive a new key for the at least one access node (2; 3) computed based on an existing higher level security key, the new key being provided to the at least one access node (2; 3) for a radio resource control reconfiguration performed between the at least one access node (2; 3) and the terminal, and the re-keying procedure being performed without performing an Authentication and Key Agreement procedure. a memory unit; and a control unit connected to the memory unit, the apparatus being configured as a functional unit of a network mobility entity to interface at least one access node (2; 3), wherein the control unit is configured to process one or more higher level security keys received from a network entity to derive at least one local level security key within an established security context for a terminal, forward said derived at least one local level security key to the at least one access node (2; 3), and invoke a context modification procedure to re-adjust the at least one local level security key with at least one local level security key maintained at the terminal within the established security context, process one or more higher level security keys received from a network entity to derive at least one local level security key within an established security context for a terminal, forward said derived at least one local level security key to the at least one access node (2; 3), and invoke a context modification procedure to re-adjust the at least one local level security key with at least one local level security key maintained at the terminal within the established security context, wherein a re-keying procedure for the at least one access node (2; 3) is performed in which a network access stratum security mode command procedure is initiated, and an updated network access stratum count parameter of a most recent network access stratum security mode command message is obtained, with the updated network access stratum parameter being used to derive a new key for the at least one access node (2; 3) computed based on an existing higher level security key, the new key being provided to the at least one access node (2; 3) for a radio resource control reconfiguration performed between the at least one access node (2; 3) and the terminal, and the re-keying procedure being performed without performing an Authentication and Key Agreement procedure.