Method and apparatus for uniquely encrypting a plurality of services at a transmission site
US5381481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1993 |
| Grant date | Jan 10, 1995 |
| Priority date | — |
| Expiry date | Aug 4, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4405
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus are described for uniquely encrypting a plurality services at a transmission site and for decrypting selected services at a reception site while reducing the amount of encryption related information that must be transmitted to the reception site for decryption purposes. A unique spreading function is generated at the transmission site for each service to be transmitted. A random quantity is then transmitted, and the random quantity is convolved with each spreading function to produce a unique encryption seed for each service. At least a portion of each service is then encrypted using the unique encryption seeds produced for each service. Only the random quantity is transmitted to the reception site along with the encrypted portions of each service. None of the unique encryption seeds are transmitted. At the reception site, the unique spreading functions generated at the transmission site for each service are regenerated. A selected service is then decrypted by (i) convolving the received random quantity with the regenerated spreading function associated with the selected service to reproduce the unique encryption seed used to encrypt the received encrypted por…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.