Matrix coding secret signalling system

In a signaling system, means to encipher signals comprising a circuit having a plurality of message terminals and a plurality of key terminals, transmission means for the signals comprising means to apply a voltage to different individual message terminals to indicate different respective signals, means to simultaneously apply a voltage to a given key terminal to indicate the respective key value, individual means in said circuit selectively actuated by the voltages applied to the particular message and key terminals, and a plurality of outgoing circuits each individually controlled by any one of a group of said selectively actuated means, each such group comprising those means selectively actuated by voltages simultaneously applied to any one of said message terminals and a different respective one of said key terminals.

In combination, a circuit network having a plural number N of input terminals constituting one group and a plural number M of input terminals constituting a second group, means to apply a voltage to any terminal of the first group and simultaneously to apply a voltage to any terminal of the second group, a number equal to N .times. M circuit controller devices each connected to receive voltage from only one terminal of each group at a time, an output circuit connection from each of said controllers, a plural number N of output terminals and connections from M different controller output circuits to each of said output terminals, the connections to any one such output terminal leading from only those controllers receiving voltage from a different one of the input terminals of said first group and a different one of the input terminals of the second group.

In combination, a circuit network having a plural number of input leads and the same number of output leas, means to apply a voltage to any one of said output leads in response to application of a voltage to any one of said input leads, comprising groups of circuit control devices, each group being adapted to be actuated in common under control of voltage on an individual input lead, each such device when actuated applying voltage in turn to a different one of said output leads, and means to independently apply voltage to said control devices in groups, each of said last groups including but one control device out of any one of said first-mentioned groups, each of said control devices requiring for its actuation application thereto of voltage from one of said input leads and from said last-mentioned means.

In a signaling system, a source of signal waves of varying amplitude, a plurality of circuit paths, means selectively responding to signal waves of different amplitude for applying a signal voltage to different ones of said paths one at a time, a second plurality of circuit paths, means to apply key voltage to different ones of said second circuit paths one at a time, a plurality of circuit controllers each adapted to be controlled by application thereto of a signal voltage and a key voltage together, means connecting each of said controllers to receive a signal voltage from one only of said circuit paths of said first plurality and from one only of said circuit paths of said second plurality, for actuating the same, a plurality of output circuit paths each connected to a different group of said circuit controllers, and means causing each circuit controller in a said group when actuated to control current flow in the respective output circuit path.

In a signal enciphering circuit, means to subdivide signal waves into stepped waves having amplitudes S.sub.1, S.sub.2, S.sub.3 to S.sub.n, a circuit network having n input leads, means operating in response to any of said specified signal wave amplitudes to impress a voltage v on a respective input lead assigned to that signal amplitude, said circuit having k other input leads, means to impress a voltage u on each of said k leads one at a time in fortuitous sequence, a number equal to the product kn of circuit control devices, means to actuate each device only in response to simultaneous application thereto of a voltage v and a voltage u received from one of said n input leads and one of said k input leads, respectively, a plurality of output leads, n in number, means to produce a voltage change in an individual output lead in response to actuation of any one of a plurality of said circuit control devices actuated from different input leads, an outgoing circuit and means to translate said voltage changes in said several output leads into stepped amplitudes of voltage in said outgoing circuit, each step being proportional to one of the amplitudes S.sub.1, S.sub.2, S.sub.3 to S.sub.n.

A secret telephone system comprising means to derive from input speech waves in a plurality of separate circuit paths a plurality of low frequency speech-defining currents, a stepper analyzer having a plurality of output leads and including means for applying a voltage to one of said leads at a time depending upon the instantaneous value of the respective speech-defining current, a permuter circuit having a signal input lead for each of said stepper analyzer output leads and respectively connected thereto, said permuter circuit having a plurality of input key leads, means to apply voltage to individual input key leads, said permuter having output terminals corresponding in number to said signal input leads, and means for applying voltage to individual output terminals selectively under the joint control of voltage applied to one of said signal input leads and voltage applied to one of said input key leads, an outgoing circuit from said permuter circuit and means for translating voltages on said output terminals into voltages of respectively different magnitude and impressing the same upon said outgoing circuit.