A security device for a cellular telephone includes a cellular telephone interface for coupling the device to the cellular telephone, a microphone, a speaker, and an analog scrambler coupling the microphone and the speaker to the cellular telephone interface. The scrambler is able to scramble voice audio from the speaker and unscramble voice audio from the cellular telephone. The device may further include a radio tuner for providing radio audio to the user through the speaker, and a recorder for recording the voice and the radio audios.