| 摘要 |
A device and method for recording data on a track ( 5 ) of a record carrier ( 1 ) are described. The record carrier ( 1 ) for use in such a device and method is also described. The record carrier ( 1 ) comprises two identical keylockers (7, 8). The keylockers contain encrypted information about the usage rights of the data on the record carrier ( 1 ). When these usage rights need to be updated, the keylockers are invalidated and new keylockers are written. Invalidating the old keylockers on a write once record carrier ( 1 ) can be done by a laser pulse with a high power level. However, data directly adjacent to the information that is invalidated becomes inaccessible. Therefore, only part of the keylockers ( 7, 8 ) is invalidated. This part needs to be an identical part of both keylockers ( 7, 8 ) so that the information of the whole keylocker cannot be restored. The distance between the neighboring data and the part of the keylocker that is invalidated is increased by arranging the information of the first keylocker ( 7 ) differently from the information of the second keylocker ( 8 ) in that the information that is to be invalidated of at least one keylocker is positioned closer to the other keylocker than in a situation in which the information of the keylockers ( 7, 8 ) is arranged identically. |
