51动漫

Microsoft wants to nail online music outfits (who could they mean?) who
鈥渆ncourage illegal distribution of copies of copyrighted material鈥�. So Bill
Gates鈥檚 crew have developed a music copy-control system which, in the overblown
prose of WO 01/06755 鈥渂rings one to the gates of the city of El Dorado where an
encoded watermark is unalterable and irremovable鈥濃�攁nd, one hopes,
inaudible. Microsoft buries copyright codes in the music by slightly increasing
and decreasing the level of selected frequencies. To stop pirates snatching
clips, the same coded message is repeated every few seconds鈥攂ut changed
each time in a secret, predetermined way. Microsoft鈥檚 detector uses the same
sequence to read each code.