Panasonic and Microsoft Corp. are working together to realise digital rights management (DRM) system interoperability between Windows Media and SD (Secure Digital) memory card, Panasonic said yesterday at the International Consumer Electronics Show (CES).

The goal is to enable consumers to securely transfer content downloaded from online music stores and protected using the Windows Media DRM system onto SD cards for playback in portable music players such as those produced by Panasonic. Panasonic developed the SD format with Toshiba and SanDisk.

SD cards use a copy protection system called CPRM (copy protection for recordable media) and the work will involve taking the Windows Media DRM-protected content and modifying it so that it's stored as a CPRM-protected file, said a Panasonic spokesperson.

Panasonic and Microsoft have already started working together on interoperability and have disclosed parts of their DRM technologies to each other, he said. The work is expected to be completed in the second half of 2005.

The technology developed under the agreement can be used worldwide by both companies although initially the focus will be on the North American market, where online sales of Windows Media DRM-protected content is greatest. Online music services such as those run by Napster, MSN Music and Wal-Mart Stores use the system. Apple Computer's iTunes Music Store uses a different and incompatible system.