Cryptography – Key management – Having particular key generator
Patent
1988-04-29
1990-05-08
Cangialosi, Salvatore
Cryptography
Key management
Having particular key generator
380 17, H04N 7167
Patent
active
049244981
ABSTRACT:
This invention discloses a new and improved method of scrambling video signals by inversion of the video information by splitting the sync pulse into plural portions and transmitting each portion of the sync pulse at a predetermined level. This improves the quality of the recovered video compared with other video inversion systems by rendering the video less sensitive to variations in the modulation depth of the modulator carrying the inverted signal, the demodulation sensitivity of the demodulator and the stability of the recovery circuits. The invention further provides additional security against pirating by allowing the scrambling circuit to operate in diverse modes, each of which will cause a TV to react differently should a conventional pirating device be employed. The invention also renders the signal capable of being transmitted with unmodified modulators of the type normally employed in the CATV industry.
REFERENCES:
patent: 2691061 (1952-03-01), Crotty et al.
patent: 2705740 (1955-04-01), Druz
patent: 3081376 (1963-03-01), Loughlin et al.
patent: 3184537 (1965-05-01), Court et al.
patent: 3439113 (1969-04-01), Walker
patent: 3460116 (1965-03-01), Waller et al.
patent: 3824332 (1974-07-01), Horowitz
patent: 4095258 (1978-06-01), Sperber
patent: 4222068 (1980-09-01), Thompson
patent: 4336553 (1982-06-01), den Toonder et al.
patent: 4396947 (1983-08-01), Cheung
patent: 4400732 (1983-08-01), Watanabe et al.
patent: 4454544 (1984-06-01), Abbott
patent: 4458268 (1984-07-01), Cicory
patent: 4467353 (1984-08-01), Citta et al.
patent: 4471380 (1984-09-01), Mobley
patent: 4511919 (1985-04-01), Forgey et al.
patent: 4551767 (1985-11-01), Higashiguchi et al.
patent: 4562465 (1985-12-01), Glaab
patent: 4568974 (1986-02-01), der Toonder et al.
patent: 4575755 (1986-03-01), Schoereberger et al.
patent: 4598318 (1986-07-01), Robbins
patent: 4613902 (1986-09-01), Ohmori
patent: 4628358 (1986-12-01), Robbins
patent: 4631603 (1986-12-01), Ryan
patent: 4679078 (1987-07-01), Wong et al.
patent: 4682360 (1987-07-01), Frederiksen et al.
patent: 4695901 (1987-09-01), Ryan
patent: 4716588 (1987-12-01), Thompson et al.
"Scrambling and Descrambling Equipment", by D. E. Kent, Director of Engineering, Jerrold International Division, General Instrument (UK) Ltd., pp. 025454-025461.
Banker Robert O.
Cole Gregory C.
Farmer James O.
Mobley Joseph G.
Schodowski Blair J.
Cangialosi Salvatore
Scientific - Atlanta, Inc.
LandOfFree
Method and apparatus for improving video scrambling and employin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for improving video scrambling and employin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for improving video scrambling and employin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2355496