Secure Digital (SD Card) is a highly secure digital camera memory card. Jointly developed by Matsushita Electronic, SanDisk and Toshiba, the SD Card weighs approximately two grams. SD Cards can be used in a variety of electronc items; digital music players, cellular phones, PDA's, digital cameras, digital camcorders, smart phones, navigation systems and electronic books. SD Cards have cryptographic security for copyrighted data based on proven security concepts from DVD audio.