Method for encrypting and embedding information in a video program
US5581614A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1994 |
| Grant date | Dec 3, 1996 |
| Priority date | — |
| Expiry date | Jan 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/9206
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods are provided for encrypting and decrypting information having a header portion and a body portion. The decrypting method includes the steps of reading a current month from a clock, extracting an odd/even month indication from the header portion, generating a first key based on the current month if the odd/even indication is odd and the current month is odd or if the odd/even indication is even and the current month is even, otherwise generating the first key based on a month previous to the current month read from the clock if the odd/even indication is odd and the current month is even or if the odd/even indication is even and the current month is odd, and using the first key for decrypting the encrypted body portion to generate a decrypted body portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.