Dynamic content-based ciphering on a control channel

In an exemplary embodiment content of a data message to be sent on a control channel is determined, and a selection is made between ciphering and not ciphering the data message based on the determined content. By example if from the content it is determined that that the data message is a SMS message, ciphering is selected and the control channel is a SACCH; else ciphering is not selected. Such a determination may be made by checking a service access point identifier for a data block comprising the data message. A data message within a data block received on the control channel is determined to be ciphered or not ciphered using only information within the data block, and the received data message is processed according to the determination. In another embodiment the FACCH is selected for sending the message if it is a SMS, and ciphering is selected for all data blocks sent on the FACCH.