System for securely storing and reading encrypted data on a data medium using a transponder
US6005940A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | May 16, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/00876
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A self contained data medium is provided with an apparatus for generating a decrypting key for decrypting stored data. Frames of encrypted data are stored on the data medium such as a video or audio disk. Each frame of data includes a header which has a frame identification number. A reader reads each frame of data including the header with the frame identification number. The reader transmits the frame number to a transponder attached to the data medium. The transponder includes a decryption engine which calculates a decryption key from the frame number and a secret deciphering key stored in the transponder. The transponder transmits the decryption key to the reader which uses the decryption key to decrypt the frame of data. The system discourages both home copying and commercial piracy of the underlying program material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.