Secret transmission of intelligence

Claim 2

In a signal privacy system, means to convert a gradually varying signal current wave into a stepped wave, means to superpose on said stepped wave a masking current varying in magnitude in a manner unrelated to the signal to produce a stepped summation current wave for transmission, and means to eliminate short portions of the summation wave at the points where the steps occur to further conceal the signal.

Claim 3

In a signal privacy system, means to convert a gradually varying signal current wave into a stepped wave, means to add thereto a masking wave, means to subtract from the resultant wave a fixed amplitude whenever the resultant wave exceeds in amplitude the maximum amplitude of the signal wave, to provide a stepped wave for transmission, and means to eliminate short portions of said last wave prior to its transmission, such eliminated portions including the points at which the steps occur.

Claim 4

In a signal privacy system, means to convert a gradually varying signal current wave into a stepped wave, means to add thereto a masking wave, means to subtract from the resultant wave a fixed amplitude whenever the resultant wave exceeds in amplitude the maximum amplitude of the signal wave, to provide a stepped wave for transmission, and means to eliminate short portions of said last wave prior to its transmission, such eliminated portions including the points at which the steps occur.

Claim 5

In speech privacy transmission, means to derive from speech waves a number of low frequency component current waves, means to convert said current waves to stepped waves, means to add key impulses to the stepped waves to disguise the latter, and means to suppress the portions of the resultant waves occurring at the beginnings and ends of the steps.

Claim 6

In speech privacy transmission, means to derive from speech waves a number of low frequency component current waves, means to convert said current waves to stepped waves, means to add key impulses to the stepped waves to disguise the latter, and means to suppress the portions of the resultant waves occurring at the beginnings and ends of the steps.

Claim 7

In speech privacy transmission, means to derive from speech message waves a number of low frequency component waves of gradually varying amplitude, means to convert said latter waves to waves whose amplitudes change suddenly in abrupt steps, means to add a masking current to the stepped waves to produce resultant stepped waves, and means to interrupt transmission of the resultant wave during the times that the amplitude is changing from one stepped value to the next.

Claim 8

In speech privacy transmission, means to derive from speech message waves a number of low frequency component waves of gradually varying amplitude, means to convert said latter waves to waves whose amplitudes change suddenly in abrupt steps, means to add a masking current to the stepped waves to produce resultant stepped waves, and means to interrupt transmission of the resultant wave during the times that the amplitude is changing from one stepped value to the next.

Claim 9

In a secret transmission system for signals, trigger tubes and means to apply the signals thereto, a timing circuit for triggering said tubes on and off at timed intervals to transmit segments of the signal differing in amplitude from one segment to the next, means to add a masking current to said current segments, said masking current also consisting of current segments of substantially the same duration as the segments produced from the signals to produce a resultant current for transmission consisting of segments, and means to suppress the beginnings and ends of the segments of the resultant current prior to transmission.

Claim 10

In a secret transmission system for signals, trigger tubes and means to apply the signals thereto, a timing circuit for triggering said tubes on and off at timed intervals to transmit segments of the signal differing in amplitude from one segment to the next, means to add a masking current to said current segments, said masking current also consisting of current segments of substantially the same duration as the segments produced from the signals to produce a resultant current for transmission consisting of segments, and means to suppress the beginnings and ends of the segments of the resultant current prior to transmission.

Claim 11

In a secret transmission system for signals, a source of signal waves, a stepper circuit for producing from said signal waves output waves varying in abrupt steps, a source of key waves, means to combine said key waves with said output waves to produce stepped resultant waves, a reentry circuit for restricting the total amplitude range of variation of said resultant waves to a range of the same order as the maximum range of signal variation, and a curbing circuit for deleting portions of the resultant waves including the beginning and end of each step.

Claim 12

In a secret transmission system for signals, a source of signal waves, a stepper circuit for producing from said signal waves output waves varying in abrupt steps, a source of key waves, means to combine said key waves with said output waves to produce stepped resultant waves, a reentry circuit for restricting the total amplitude range of variation of said resultant waves to a range of the same order as the maximum range of signal variation, and a curbing circuit for deleting portions of the resultant waves including the beginning and end of each step.

Claim 13

In a secret transmission system having a transmitter and receiver with sources for supplying duplicate key waves at both transmitter and receiver, a message coder at the transmitter comprising a message stePper, key stepper, reentry circuit and curbing circuit and at the receiver a message decoder comprising a message stepper, key stepper, reentry circuit and curbing circuit for recovering the original message.

Claim 14

In a secret transmission system having a transmitter and receiver with sources for supplying duplicate key waves at both transmitter and receiver, a message coder at the transmitter comprising a message stePper, key stepper, reentry circuit and curbing circuit and at the receiver a message decoder comprising a message stepper, key stepper, reentry circuit and curbing circuit for recovering the original message.

Claim 15

A receiving circuit for secret coded message waves resulting from combination of message waves and a secret key wave; said receiving circuit comprising a message stepper, a source of duplicate key waves, a combining circuit for stepped message waves and key waves, and a circuit for suppressing portions of the combined waves during which transitions occur from an amplitide representing one step to an amplitude representing another step.

Claim 16

A receiving circuit for secret coded message waves resulting from combination of message waves and a secret key wave; said receiving circuit comprising a message stepper, a source of duplicate key waves, a combining circuit for stepped message waves and key waves, and a circuit for suppressing portions of the combined waves during which transitions occur from an amplitide representing one step to an amplitude representing another step.

Claim 17

In a system of speech transmission including analysis of speech waves into low frequency defining waves at a transmitting point and synthesis of speech waves at a receiving point under control of said defining waves, duplicate key wave sources at both points, means to convert the defining waves each to a stepped wave before transmission, means to combine the key wave with the stepped wave to produce resultant waves, means to reduce peak portions of the resultant waves where necessary to confine their total amplitude range to the normal range of said stepped wave alone, and means to suppress transmission of the portions of said last waves within which transitions occur from one stepped value to another to conceal evidence of peak reductions.

Claim 18

In a system of speech transmission including analysis of speech waves into low frequency defining waves at a transmitting point and synthesis of speech waves at a receiving point under control of said defining waves, duplicate key wave sources at both points, means to convert the defining waves each to a stepped wave before transmission, means to combine the key wave with the stepped wave to produce resultant waves, means to reduce peak portions of the resultant waves where necessary to confine their total amplitude range to the normal range of said stepped wave alone, and means to suppress transmission of the portions of said last waves within which transitions occur from one stepped value to another to conceal evidence of peak reductions.

Claim 19

In a secret speech transmission system, means to analyze speech message waves into low frequency defining waves, a stepper circuit for each defining wave comprising a respective group of gas discharge tubes, means to set said tubes to break down individually at different instantaneous amplitudes of the given defining waves, a timing circuit for subjecting said steppers periodically to control by the respective defining wave, a source of key waves for each defining wave, means to combine the stepped defining waves and key waves to produce resultant coded waves and a reentry circuit and a curbing for each coded wave.

Claim 20

In a secret speech transmission system, means to analyze speech message waves into low frequency defining waves, a stepper circuit for each defining wave comprising a respective group of gas discharge tubes, means to set said tubes to break down individually at different instantaneous amplitudes of the given defining waves, a timing circuit for subjecting said steppers periodically to control by the respective defining wave, a source of key waves for each defining wave, means to combine the stepped defining waves and key waves to produce resultant coded waves and a reentry circuit and a curbing for each coded wave.

Claim 21

In a privacy system, a source of message waves, a source of key waves, a message stepper and a key stepper each comprising a group of gas discharge tubes having stepped break-down characteristics from tube to tube, a timing circuit, means under control of said timing circuit for generating timed impulses and applying the same to said groups of gas discharge devices in common, said impulses during their occurrence exposing said steppers to the influence of said message waves and key waves respectively, and means for restoring said gas discharge tubes to normal at a given time after the end of each exposure period.

Claim 22

In a privacy system, a source of message waves, a source of key waves, a message stepper and a key stepper each comprising a group of gas discharge tubes having stepped break-down characteristics from tube to tube, a timing circuit, means under control of said timing circuit for generating timed impulses and applying the same to said groups of gas discharge devices in common, said impulses during their occurrence exposing said steppers to the influence of said message waves and key waves respectively, and means for restoring said gas discharge tubes to normal at a given time after the end of each exposure period.

Claim 23

In a secret signaling system, means to convert message waves into waves varying in amplitude in abrupt steps, means to add thereto a secret key wave also varying in abrupt steps to produce summation currents varying in abrupt steps, means to reduce the amplitude range of said summation currents to substantially the amplitude range represented by the message waves, and means to transmit the central portion only of each summation current step.

Claim 24

In a secret signaling system, means to convert message waves into waves varying in amplitude in abrupt steps, means to add thereto a secret key wave also varying in abrupt steps to produce summation currents varying in abrupt steps, means to reduce the amplitude range of said summation currents to substantially the amplitude range represented by the message waves, and means to transmit the central portion only of each summation current step.

Claim 25

In a secret signaling system, means at a transmitting point for automatically coding a message wave to render the transmission secret comprising a message stepper, a source of key waves and means to add the key waves to the stepped message waves to produce a stepped summation wave, means to reduce by a fixed quantity the amplitude of the summation wave having peak amplitudes in excess of a given maximum, and means to invert the resultant waves, a source of duplicate key waves at a receiving point, means to add the key waves from said latter source to the received waves to produce summation waves, means to reduce by a fixed quantity the amplitude of the last-mentioned summation waves having peak amplitudes in excess of a given maximum, and means to invert the resultant waves to recover the message waves.

Claim 26

In a secret signaling system, means at a transmitting point for automatically coding a message wave to render the transmission secret comprising a message stepper, a source of key waves and means to add the key waves to the stepped message waves to produce a stepped summation wave, means to reduce by a fixed quantity the amplitude of the summation wave having peak amplitudes in excess of a given maximum, and means to invert the resultant waves, a source of duplicate key waves at a receiving point, means to add the key waves from said latter source to the received waves to produce summation waves, means to reduce by a fixed quantity the amplitude of the last-mentioned summation waves having peak amplitudes in excess of a given maximum, and means to invert the resultant waves to recover the message waves.