Data management system
US6002772A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 2, 1997 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Apr 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2463/101
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To prevent piracy or leakage of data content, a cryptography technique and electronic watermark technique are combined together and used. In a data content supplied to a user, a user data is entered as electronic watermark by a data management center, and the data content with an electronic watermark entered in it is encrypted using a crypt key and is supplied. The encrypted data content is decrypted using a crypt key distributed from the data management center and is used. In case it is to be stored, it is encrypted using another crypt key. In case the data content is copied and transferred to other user, a user data of the other user is entered as electronic watermark, and a scenario to enter the user data of the other user as electronic watermark is registered at the data management center, and the data content with electronic watermark entered in it is encrypted using another crypt key and is supplied. When the validity of the other user is confirmed by the scenario, another crypt key is distributed to the other user. The encrypted data content is decrypted using another crypt key and is used. When it is to be stored, it is encrypted using still another key. In case the data co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.