Electronic watermarking method, digital information distribution system using such method, and storage medium storing program of such method
US6560339B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1999 |
| Grant date | May 6, 2003 |
| Priority date | — |
| Expiry date | Feb 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/8358
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An electronic watermarking method includes the steps of generating a plurality piece of information with different electronic watermark information, generating a plurality piece of encrypted information through encryption of the plurality piece of information with each independent encryption key, generating a plurality of encrypted encryption keys through encryption of each independent encryption key with each different encryption key, transmitting the plurality piece of encrypted information and the plurality of encrypted encryption keys to a user, the first to fourth steps being executed by a server, and selecting each pair of a piece of the plurality of encrypted information and a corresponding encrypted encryption key, the fifth step being executed by the user, wherein only some of the encryption keys are multiplied by random numbers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.