PROTECTED STORAGE OF DATA ON OPTICALLY-READABLE MEDIA

摘要

Protection is provided for optically readable media. Data may be scrambled, encrypted, or otherwise obscured by apportioning the data (D1-D6) across multiple layers (54, 56) of a disc in a secret pattern. Pattern information may be supplied in the form of a key to authorized devices or users. The data can only be read by an optical drive with the proper hardware having access to this key. Switchable mirrored regions are provided on the optical medium to selectively block and unblock an optical reader head from reading the data. To read the data back, an authorized/licensed device may use the key to selectively switch the electrochromic regions (55) so that the reader head may access the data while alternately focusing on different data layers, as needed, to obtain the data in the proper order.