Cryptography – Key management – Having particular key generator
Patent
1990-02-20
1992-05-12
Tarcza, Thomas H.
Cryptography
Key management
Having particular key generator
380 10, 380 20, 380 19, H04N 7167
Patent
active
051134411
ABSTRACT:
A method of scrambling a television signal and a method of and apparatus for descrambling a television signal is provided. An audio signal is used on which a key signal containing compression information and information concerning the position of a vertical blanking interval is superimposed on a portion of the audio signal corresponding to a horizontal blanking interval. In addition, a pseudo-key signal is superimposed on the audio signal at a portion which corresponds to a vertical blanking interval, so that the vertical blanking interval cannot be detected through the detection of the audio signal. As a result, an expansion signal for expanding the signal in the horizontal blanking interval and vertical blanking interval compressed by scrambling cannot be formed in its normal position. Thus, unauthorized access is difficult. Descrambling can be performed by detecting the vertical blanking interval based on the information concerning the position of the vertical blanking interval contained in the key signal, and decoding the information for the position which is transmitted in the form of out-band data. Compression information can then be extracted from the key signal based on the detected vertical blanking interval, and an expansion signal for expanding the signal in the horizontal and vertical blanking periods can be generated.
REFERENCES:
patent: 3684823 (1972-08-01), McVoy
patent: 3916091 (1975-10-01), Kirk, Jr. et al.
patent: 3975585 (1976-08-01), Kirk, Jr. et al.
patent: 4064536 (1977-12-01), Saeki et al.
patent: 4325079 (1982-04-01), Little
patent: 4348691 (1982-09-01), Mistry
patent: 4388643 (1983-06-01), Aminetzah
patent: 4430699 (1984-02-01), Segarra et al.
patent: 4463376 (1984-07-01), Osaka et al.
patent: 4484027 (1984-11-01), Lee et al.
patent: 4531020 (1985-07-01), Wechselberger et al.
patent: 4535355 (1985-08-01), Arn et al.
patent: 4600942 (1986-07-01), Field et al.
patent: 4613901 (1986-09-01), Gilhousen et al.
patent: 4621285 (1986-11-01), Schilling et al.
patent: 4631603 (1986-12-01), Ryan
patent: 4688247 (1987-08-01), Davidov
patent: 4691354 (1987-09-01), Palminteri
patent: 4716558 (1987-12-01), Katayama et al.
patent: 4723283 (1988-02-01), Nagasawa et al.
patent: 4736422 (1988-04-01), Mason
patent: 4790010 (1988-12-01), Sgrignoli
patent: 4794643 (1988-12-01), Saeki et al.
patent: 4802215 (1989-01-01), Mason
patent: 4839922 (1989-06-01), Imasaki et al.
patent: 4953208 (1990-08-01), Ideno
Cain David
Pioneer Electronics Corporation
Tarcza Thomas H.
LandOfFree
Method for scrambling a television signal and method and apparat 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 for scrambling a television signal and method and apparat, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for scrambling a television signal and method and apparat will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2427629