A method for encrypting radio resource control (RRC) messages exchanged between a wireless communication device and a node in a wireless communication system includes separating sequence number rollover events from mobility events while encrypting radio resource control (RRC) messages for exchange within a wireless communication system. According to the method, the sequence number rollover events and mobility events are separated by utilizing a state transition counter, a handover counter, and an overflow counter such that, when the state counter is incremented due to occurrences of a first group of events, the handover counter and the overflow counter are re-set to zero and, when the handover counter is incremented due to occurrences of a second group of events the overflow counter is re-set to zero. The method further includes providing one or more outputs from the state transition counter, the handover counter, and the third overflow counter as one or more inputs to a crypto algorithm for encrypting RRC messages.