CSS:  Using CSS
 Get an Authentication Grant ID (AGID)
 Usually only 1 AGID available on a drive

 Get the Disk Key (only need 5 bytes, get all 2048)
 Challenge/response using a player key

 When you need to play a title, get its Title Key
 At this point, drive checks the region

 Decrypt Title Key (5 bytes) using the Disk Key

 Use the Title Key to decrypt any encrypted sectors
 Up to 50% of the sectors may be encrypted
 Usually at least 30% encrypted
 hh says several of his disks right at 50%