Providing consumer product designers with storage options from 8 MB to 64 MB, the Secure Digital (SD) memory card is designed to comply with all three levels of the Secure Digital Music Industry (SDMI) security requirements. Both non-protected (category I) and copy protected (categories II and III) material can be stored on the card. The copy-protected material can be secured either by a unique card bound identification (category II) or by an active cryptography algorithm (category III), that involves challenge/response protocols against a private key.
The card is packaged with a nine-pin SD interface that allows data transfer rates of up to 2 MB/s and is said to eventually provide a rate of up to 10 MB/s. Ergonomically designed, the card measures 32 mm x 24 mm x 2.1 mm, approximately the size of a postage stamp, and weighs 2g.Based on NAND technology, there are currently three devices in the series: the 8-MB SD-M0800B, 16-MB SD-M1600B, 32-MB SD-M3201B, and the 64-MB SD-M6401B.