According to an exemplary embodiment, there is provided a method of operating a terminal device. The method includes operating the terminal device in a connected state with respect to the communication network. The method further includes receiving a first signal from a first radio access node in the communication network indicating that the connected state is to be suspended, the first signal having information for use in determining a first key for encrypting data to be sent between the terminal device and the first radio access node or another radio access node in the communication network if the connected state is resumed.