Secure Digital

Origins and standardization

Panasonic and Toshiba, who had previously collaborated on the Super Density Disc (a DVD precursor), reused its stylized "SD" logo for the Secure Digital (SD) card format. Anticipating the growth of MP3 players, they also advocated for digital rights management (DRM) support seeking to reassure content publishers wary of piracy. The DRM system adopted—Content Protection for Recordable Media (CPRM)—had been developed earlier in partnership with IBM and Intel and complied with the Secure Digital Music Initiative standard. Although often cited as a factor in the format's broad industry support, CPRM was rarely implemented in practice. SD cards also featured a mechanical write-protect switch, and early SD slots maintained backward compatibility with MMC cards. In early 2000, the first commercial SD cards offering 8 MB of storage were released, with larger capacity versions following shortly after. By August 2000, 64 MB cards were being sold for approximately US$200 (equivalent to $374 in 2025). According to SanDisk, consumer adoption was accelerated by Toshiba and Panasonic's commitment to launching compatible devices in parallel with the cards.