Method and apparatus for communicating scrambled digital data
USRE36919E · kind E · reissue
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Jun 12, 2018 |
Classification
- Technology area (CPC —)General
Abstract
.[.A copy prevention method and apparatus of a digital magnetic recording/reproducing system performs the copy prevention function by encoding to insert a marker involving copy prevention function information and executing the function and allows a program supplier to realize a desired copy prevention function of various patterns, in which the marker formed by a control word for scrambling audio and video bit straps and copy prevention information for preventing an illegal copy is encrypted by an encoded key to be multiplexed with the audio and video bit strips scrambled by the control word. The marker transmitted is detected from the bit strips to be decrypted and analyzed by the encoded key to determine whether the copy is permitted or not, so that the detected marker is updated to be recorded on a video tape and the control word is produced from the marker to perform the descrambling to supply the result to a monitor to be displayed. Thus, the program supplier selects the copy prevention function, and a separate format converting apparatus is not required since a field defined within a GA format is utilized while an existing DVCR is not need to be changed for performing the copy…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.