Cryptography – Cryptanalysis
Patent
1986-11-04
1988-05-31
Buczinski, Stephen C.
Cryptography
Cryptanalysis
333176, 455 1, 455286, 455339, H04N 7167, H03H 700
Patent
active
047486678
ABSTRACT:
Scrambling and descrambling systems utilizing jamming signals provide improved pictures with minimal distortion due to ghosts and artifacts. The television signal is combined with a jamming signal or signals located preferably in the vestigial sideband (VSB) of the modulated picture carrier and at about a null in the spectrum of the modulation of the picture carrier by the horizontal sync. The jamming signal or signals also preferably are placed between the harmonic components of the horizontal sync which define the horizontal sync spectrum and at frequencies which comply with governmental regulations respecting frequency locations of strong signals of CATV purposes. The jamming signals are generated by phase locking to the horizontal sync signals of the television signals or to a submultiple of the horizontal sync frequency. Artifacts are further reduced by preemphasis of the transmitted television signal in the sideband opposite to that in which the jamming signal or signals are located and spaced by an equal frequency increment from the location of the jamming signal energy. In order to extract the jamming signal, so as to descramble the television signal for reproduction in the subscriber's television receiver, a network including at least one surface acoustic wave (SAW) resonator device is embedded in an all-pass network which allows essentially lossless transmission of the television signal spectrum, except for the jamming signal energy and enables that energy to be located close to (e.g., approximately 228 KHz) from the picture carrier in the VSB for enhanced security.
REFERENCES:
patent: 2905747 (1959-09-01), Kidd
patent: 3059054 (1962-10-01), Reiter
patent: 3202758 (1965-08-01), Brownstein
patent: 3347982 (1967-10-01), Bass
patent: 3760097 (1973-09-01), Burroughs
patent: 3859457 (1975-01-01), Kirk
patent: 3896262 (1975-07-01), Hudspeth
patent: 3898375 (1975-08-01), Hannan et al.
patent: 3989887 (1976-11-01), Murphy
patent: 4024575 (1977-05-01), Harney
patent: 4074311 (1978-02-01), Tanner
patent: 4097894 (1978-06-01), Tanner
patent: 4099203 (1978-07-01), Garodnick
patent: 4126837 (1978-11-01), Koyamada et al.
patent: 4145716 (1979-03-01), Uemura
patent: 4148064 (1979-04-01), Reed
patent: 4222067 (1980-09-01), Stern
patent: 4268860 (1981-05-01), Blonder
patent: 4357709 (1982-11-01), Butler
patent: 4398214 (1983-08-01), Gargini
patent: 4466017 (1984-08-01), Banker
patent: 4577168 (1986-03-01), Hartmann
patent: 4581765 (1986-04-01), Stec
patent: 4623918 (1986-11-01), Chomet
Farmer James O.
Kozushin Anatoly
Kruse Herman A.
LaFay William P.
Lewis Christopher P.
Buczinski Stephen C.
Lukacher Martin
Scientific Atlanta
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