Communications secrecy system

Claim 2

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled, comprising means for employing at a given time a unique unscrambling code for decoding the scrambled intelligence signals, and means in the decoder for coding at least some of the intelligence signals during any of said given time in which no code whatsoever is employed to effect said decoding.

Claim 3

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled, comprising means for employing at a given time a unique unscrambling code for decoding the scrambled intelligence signals, and means in the decoder for coding at least some of the intelligence signals during any of said given time in which any code other than said unique code including no code whatsoever is employed to effect said decoding.

Claim 4

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled, comprising means for employing at a given time a unique unscrambling code for decoding the scrambled intelligence signals, and means in the decoder for coding at least some of the intelligence signals during any of said given time in which any code other than said unique code including no code whatsoever is employed to effect said decoding.

Claim 5

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled comprising means for employing at a given time a unique unscrambling code for decoding the scrambled intelligence signals, and means in the decoder for increasing the coding of the said intelligence signals during any of said given time in which no code whatsoever is employed to effect said decoding.

Claim 6

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled comprising means for employing at a given time a unique unscrambling code for decoding the scrambled intelligence signals, and means in the decoder for increasing the coding of the said intelligence signals during any of said given time in which no code whatsoever is employed to effect said decoding.

Claim 7

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled and in which continually varying code signal combinations corresponding to at least part of the system''s scrambling code are transmitted to control decoding functions at least partially: comprising a plurality of storage stages each of which has at least two storage conditions; means, including variable connection means for effectively applying each combination of transmitted code signals to said storage stages to cause same to change their storage conditions from time to time at least when the connections in said variable connection means are made in accordance with at least part of a predetermined unscrambling code for decoding said scrambled intelligence signal only when said predetermined unscrambling code should be and actually is in effect; and means coupled to the output of at least certain of said storage stages for interfering with at least some of the intelligence signals when no one of the so coupled storage stages changes its storage condition from time to time.

Claim 8

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled and in which continually varying code signal combinations corresponding to at least part of the system''s scrambling code are transmitted to control decoding functions at least partially: comprising a plurality of storage stages each of which has at least two storage conditions; means, including variable connection means for effectively applying each combination of transmitted code signals to said storage stages to cause same to change their storage conditions from time to time at least when the connections in said variable connection means are made in accordance with at least part of a predetermined unscrambling code for decoding said scrambled intelligence signal only when said predetermined unscrambling code should be and actually is in effect; and means coupled to the output of at least certain of said storage stages for interfering with at least some of the intelligence signals when no one of the so coupled storage stages changes its storage condition from time to time.

Claim 9

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled and in which different code signal combinations corresponding to at least part of the system''s scrambling code are transmitted to control decoding functions: comprising a plurality of storage stages each of which has at least two storage conditions; means, including a plurality of switching means each of which is effectively settable to any one of a plurality of positions for effectively applying each combination of transmitted code signals to said storage stages, for decoding said scrambled intelligence signal when the said switching means are effectively set to a respective predetermined position; and means coupled to the output of at least certain of said storage stages for interfering with at least some of the intelligence signals when the said switching means are effectively set in such positions as to effectively apply none of the code signal combinations to any of the storage stages.

Claim 10

A decoder for use with a receiver in a secrecy system of the type in which at least part of the intelligence signals are scrambled and in which different code signal combinations corresponding to at least part of the system''s scrambling code are transmitted to control decoding functions: comprising a plurality of storage stages each of which has at least two storage conditions; means, including a plurality of switching means each of which is effectively settable to any one of a plurality of positions for effectively applying each combination of transmitted code signals to said storage stages, for decoding said scrambled intelligence signal when the said switching means are effectively set to a respective predetermined position; and means coupled to the output of at least certain of said storage stages for interfering with at least some of the intelligence signals when the said switching means are effectively set in such positions as to effectively apply none of the code signal combinations to any of the storage stages.

Claim 11

A decoder as in claim 5 wherein one of the positions for each of the said switching means is an open position and the intelligence signal gets interfered with when each of the switching means is effectively set to its open position.

Claim 12

A decoder for use with a receiver in a television system of the type in which one but not the other of the picture program signals and sound program signals is scrambled and in which decoding control signals are transmitted, comprising means for effecting a plurality of different output conditions changeable from time to time conditionally in response to different ones of said control signals when operated at least partially in accordance with a given unscrambling code during a given period of time for decoding the scrambled program signals when that code is in effect during that time period, and means responsive to said output conditions for interfering with at least the unscrambled program signals if said output conditions do not change from time to time in response to different control signals.

Claim 13

A decoder for use with a receiver in a television system of the type in which one but not the other of the picture program signals and sound program signals is scrambled and in which decoding control signals are transmitted, comprising means for effecting a plurality of different output conditions changeable from time to time conditionally in response to different ones of said control signals when operated at least partially in accordance with a given unscrambling code during a given period of time for decoding the scrambled program signals when that code is in effect during that time period, and means responsive to said output conditions for interfering with at least the unscrambled program signals if said output conditions do not change from time to time in response to different control signals.

Claim 14

In a decoder for use with a receiver in a television system of the type in which the received picture signals but not the received audio signals are scrambled, their being apparatus in the decoder for generating invalid decoding output signals if any wrong unscrambling code is employed with the decoder by a user thereof, and for generating continually changing valid decoding output signals, the improvement of means for rendering the uncoded audio signals unsatisfactory to listening if anything but the correct unscrambling code including no code whatsoever is employed, comprising means for generating recurring signals in response to repeated generations of said invalid decoding signal in the decoder, means for generating other recurring signals in response to the lack of change from time to time in the output signal from said generating apparatus, and means responsive to at least some of said recurring signals from each of said means for interfering with the uncoded audio signals.

Claim 15

In a decoder for use with a receiver in a television system of the type in which the received picture signals but not the received audio signals are scrambled, their being apparatus in the decoder for generating invalid decoding output signals if any wrong unscrambling code is employed with the decoder by a user thereof, and for generating continually changing valid decoding output signals, the improvement of means for rendering the uncoded audio signals unsatisfactory to listening if anything but the correct unscrambling code including no code whatsoever is employed, comprising means for generating recurring signals in response to repeated generations of said invalid decoding signal in the decoder, means for generating other recurring signals in response to the lack of change from time to time in the output signal from said generating apparatus, and means responsive to at least some of said recurring signals from each of said means for interfering with the uncoded audio signals.

Claim 16

For use with equipment having a terminal on which any one of a plurality of different voltage levels can occur at different times with at least one of those levels being on one polarity relative to a given threshold voltage and the remainder of the levels being of the opposite polarity relative to that voltage, apparatus for generating one pulse per each recurrence of the said one polarity voltage level within a given time after it has recurred a predetermined number of times during a predetermined period of time, comprising means for passing only those levels which are of the said one polarity, and a step integrator for integrating each of said one polarity levels so passed and stepping to a different initial voltage for each of the said predetermined number of times that the one polarity level occurs within said predetermined period of time and then stepping, if said predetermined number of the said one polarity levels occurred within said period of time, to a further initial voltage for each successive recurrence of the said one voltage level which follows its predecessor within said given time, each such step to said further voltage being one of said pulses.

Claim 17

For use with equipment having a terminal on which any one of a plurality of different voltage levels can occur at different times with at least one of those levels being on one polarity relative to a given threshold voltage and the remainder of the levels being of the opposite polarity relative to that voltage, apparatus for generating one pulse per each recurrence of the said one polarity voltage level within a given time after it has recurred a predetermined number of times during a predetermined period of time, comprising means for passing only those levels which are of the said one polarity, and a step integrator for integrating each of said one polarity levels so passed and stepping to a different initial voltage for each of the said predetermined number of times that the one polarity level occurs within said predetermined period of time and then stepping, if said predetermined number of the said one polarity levels occurred within said period of time, to a further initial voltage for each successive recurrence of the said one voltage level which follows its predecessor within said given time, each such step to said further voltage being one of said pulses.

Claim 18

Apparatus as in claim 9 wherein said stop integrator is a step counter having means for decreasing its output potential toward said given threshold voltage after each received one of the said one polarity levels is counted thereby.

Claim 19

For use with equipment having a terminal on which any one of a plurality of different voltage levels can conditionally occur at different times with at least one of those levels being of a first polarity relative to a threshold voltage and the remainder of those levels being of the opposite polarity relative to that voltage, means for generating pulses whenever the voltage level at said terminal does not change at least in a certain direction within a predetermined time, and means for generating one pulse per each recurrence of the said first polarity voltage level within a given time at least after it has recurred a predetermined number of times during a predetermined period of time, wherein the last mentioned means includes means for passing only those levels which are of the said one polarity, and a step integrator for integrating each of the said one polarity levels so passed and stepping to a different initial voltage for each of the said predetermined number of times that the one polarity level occurs within said period of time, to a further but limiting initial voltage for each successive recurrence of the said one voltage level which follows its predecessor within said given time, each such step to such limited voltage being one of the said pulses.

Claim 20

For use with equipment having a terminal on which any one of a plurality of different voltage levels can conditionally occur at different times with at least one of those levels being of a first polarity relative to a threshold voltage and the remainder of those levels being of the opposite polarity relative to that voltage, means for generating pulses whenever the voltage level at said terminal does not change at least in a certain direction within a predetermined time, and means for generating one pulse per each recurrence of the said first polarity voltage level within a given time at least after it has recurred a predetermined number of times during a predetermined period of time, wherein the last mentioned means includes means for passing only those levels which are of the said one polarity, and a step integrator for integrating each of the said one polarity levels so passed and stepping to a different initial voltage for each of the said predetermined number of times that the one polarity level occurs within said period of time, to a further but limiting initial voltage for each successive recurrence of the said one voltage level which follows its predecessor within said given time, each such step to such limited voltage being one of the said pulses.

Claim 21

Apparatus as in claim 11 wherein the first mentioned means includes a discharge device which is conductive only when at least a predetermined potential is impressed across it, means including a parallel combination of a condenser and an impedance serially coupled via a junction to said device, means for applying a potential greater in amplitude than said predetermined potential across the series combination of said device and last mentioned means to cause alternate conduction and nonconduction of said device, and means for applying at least certain changes in voltage levels as they occur at said terminal to said junction to charge said condenser and prevent said discharge device from conducting.

Claim 22

Apparatus as in claim 12 wherein said discharge device includes at least one neon bulb.

Claim 23

Apparatus as in claim 11 wherein said step integrator is a step counter having means for decreasing its output potential toward said second threshold voltage after each received one of the said one polarity levels is counted thereby.

Claim 24

In a decoder for use with a receiver in a scrambled television system of the type in which received decoding signals are variable from time to time to represent any one of a variety of different signal combinations, the decoder being of the type to establish at a given terminal in conditional response to said different signal combinations any one of M-1 different voltage levels when the proper unscrambling code is employed in the decoder and to establish a recurring Mth level when an improper unscrambling code is employed therein, the improvement of apparatus for causing interference with a program signal only when other than the proper unscrambling code is operative in the decoder, comprising means for generating one pulse per each recurrence within a given time of the said Mth level at least after it has recurred a predetermined number of times during a given time period, means for generating pulses whenever the voltage at said terminal does not change at least in a certain direction after a predetermined time, and means for utilizing the pulses from both of said generating means for interfering with a program signal.

Claim 25

In a decoder for use with a receiver in a scrambled television system of the type in which received decoding signals are variable from time to time to represent any one of a variety of different signal combinations, the decoder being of the type to establish at a given terminal in conditional response to said different signal combinations any one of M-1 different voltage levels when the proper unscrambling code is employed in the decoder and to establish a recurring Mth level when an improper unscrambling code is employed therein, the improvement of apparatus for causing interference with a program signal only when other than the proper unscrambling code is operative in the decoder, comprising means for generating one pulse per each recurrence within a given time of the said Mth level at least after it has recurred a predetermined number of times during a given time period, means for generating pulses whenever the voltage at said terminal does not change at least in a certain direction after a predetermined time, and means for utilizing the pulses from both of said generating means for interfering with a program signal.

Claim 26

Apparatus as in claim 15 wherein the means for generating pulses whenever the voltage at said terminal does not change comprises a relaxation oscillator and means coupled to said terminal for inhibiting operation of the relaxation oscillator in response to at least certain voltage changes at said terminal.

Claim 27

Apparatus as in claim 15 wherein the means for generating pulses when the voltage level at said terminal does change which is conductive only when at least a predetermined potential is impressed across it, means includIng a parallel combination of a condenser and an impedance serially coupled via a junction to said device, means for applying a potential greater in amplitude than said predetermined potential across the series combination of said device and last mentioned means to effect at least said predetermined potential across said device and a consequent conduction thereof whereupon a charge builds up on said condenser and increases the voltage at said junction so that the potential across said devices reduces and makes the device nonconductive while the condenser discharges through at least said impedance until the voltage at said junction decreases sufficiently to again place at least said predetermined potential across said device to cause it to conduct again, and means coupled between said terminal and condenser for charging the latter in response to at least certain changes in the voltage at said terminal to maintain said discharge device nonconducting for a predetermined time.

Claim 28

Apparatus as in claim 15 wherein the means for generating one pulse for each recurrence of the said Mth voltage level at least after it has recurred a predetermined number of times during a given time period, includes means for gating out a signal each time the Mth voltage level occurs, and a step integrator for integrating each of the said gated pulses.

Claim 29

Apparatus as in claim 15 wherein the means for interfering with said picture signal comprises means responsive to a pulse from either of said pulse generating means to cause momentary interruption of a program signal.

Claim 30

Apparatus as in claim 19 wherein the interruption means includes means for temporarily cutting off at least a portion of the total program signal.

Claim 31

Apparatus as in claim 20 wherein the means for temporarily cutting off at least a part of the program signals includes means for momentarily reducing the bandwidth of a circuit through which program signals pass.

Claim 32

Apparatus as in claim 15 wherein the interfering means includes means responsive to pulses from both said generating means for causing generation of a signal which itself interferes with at least a part of the program signal to make that part unsuitable in reproduction.

Claim 33

Apparatus as in claim 22 including means for causing the generated signal to be keyed on and off at an annoying rate.

Claim 34

Apparatus as in claim 22 including means for causing the frequency of the generated signal to sweep above and below its center frequency.