TrustedFlash was the brand-name given to SD cards developed by SanDisk that included Digital Rights Management (DRM) technology. Testing SD and microSD cards as means of content distribution makes a lot of sense given that many notebooks and other devices today come equiped with card reading capabilities. Along with the cards themselves, TrustedFlash included a subscription manager enabling the cards to be used for digital subscription music services. When announced in 2005, it was believed that the technology may even extend beyond music (as an obvious choice) to on-demand content such as feature films and online games.
Despite their speck-like proportions - a mere 18 mm long and 2g in weight - the cards can offer enough storage space to hold thousands of DRM -protected MP3, films, photographs or games. The "Gruvi" variety of the cards used the microSD format for compatibility with small devices, such as portable MP3 players, mobile phones and GPS technology. SanDisk had hoped that content distributors would ship content using the technology, but that so far has been a rare occurance, with only one really popular release made (from Rolling Stones).
In the case of the Rolling Stones, the release also included four extra albums on the card that could be unlocked for an extra fee, showing the card's capabilities to protect access to content from users.