US3557307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ciphering machine
Assignee: TRANSVERTEX AB
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Filing: 1969-03-10
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Granted: 1971-01-19
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Expires: 1989-03-10
Abstract
Abstract This invention relates to a ciphering machine for ciphering text in clear produced in binary form by superimposing every text in clear character signal with a variable ciphering signal. Such a machine comprises a number of electric devices stepped in parallel with cyclic operations, for example shift registers, the cycles being mutually different, said devices being formed, for example, by chains or rows of mutually different numbers of bistable flip-flops. The initial states of said flip-flops so were set according to a scheme of preferably random choice that the states of flip-flops stepped in parallel in every column in the different shift registers together define a ciphering character. These column characters, thus, automatically change their nature as soon as a shift register has completed a cycle.
Inventors
- 👤 Bengt Florin
- 👤 Kalevi Loimaranta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:13
CPC Classifications
G; G09; G09C; G09C1/00; G09C1/06; G09C1/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
187 words
In ciphering machine for ciphering text in clear produced in binary form, by superposing every text-in-clear character signal with a variable ciphering signal, comprising a plurality of electric devices stepped in parallel, said devices each having a different and repetitive operative cycle and forming an array of parallel rows of a different number of bistable flip-flops, the initial states of which are set according to an arbitrary scheme so that the states of flip-flops sTepped in parallel define together, in every flip-flop column of said array, a ciphering character, whereby said column characters automatically change their bit composition every time a row of flip-flops has completed a cycle and starts a new one; the improvement comprising means, responsive to the present contents of a flipflop column in a preselected reference position, to select, at each ciphering moment or step, at least one of the remaining flip-flop columns in the flip-flop array, as determined by said contents, and to transfer the signals corresponding to the states of the selected flip-flops to an adding device for producing said ciphering signal which is to be superposed on the text-in-clear signal.
Claim 2
Dependent Claim
187 words
In ciphering machine for ciphering text in clear produced in binary form, by superposing every text-in-clear character signal with a variable ciphering signal, comprising a plurality of electric devices stepped in parallel, said devices each having a different and repetitive operative cycle and forming an array of parallel rows of a different number of bistable flip-flops, the initial states of which are set according to an arbitrary scheme so that the states of flip-flops sTepped in parallel define together, in every flip-flop column of said array, a ciphering character, whereby said column characters automatically change their bit composition every time a row of flip-flops has completed a cycle and starts a new one; the improvement comprising means, responsive to the present contents of a flipflop column in a preselected reference position, to select, at each ciphering moment or step, at least one of the remaining flip-flop columns in the flip-flop array, as determined by said contents, and to transfer the signals corresponding to the states of the selected flip-flops to an adding device for producing said ciphering signal which is to be superposed on the text-in-clear signal.
Claim 3
Dependent Claim
183 words
A machine according to claim 1, where the means for selecting at least one certain flip-flop column comprises a plurality f of character selectors individually associated with a different one of said remaining flip-flop columns, and each of said character selectors having a plurality of inputs of the same number as that of the flip-flop rows, the inputs of all of said character selectors being connected in parallel to the corresponding outputs of the flip-flops in the column of said reference position, and each of said character selectors having its output connected to one input of an AND-gate, the second input of which is connected to the output of an adding circuit, said adding circuits having their respective inputs connected with the outputs of the flip-flops in the associated columns such, that for a certain character in said reference position column only one character selector is activated to supply an output signal to its AND-gate, at the second input of which the output signal from its adding circuit is always present, for effecting an output signal from said AND-gate, representing said ciphering signal.
Claim 4
Dependent Claim
58 words
A machine according to claim 2, wherein each of the character selectors comprises a system of AND-gates having its respective input connected to the output of the flip-flop of said reference position column in such a manner that an output signal from the gate system is obtained only in response to certain definite characters in said reference column.
Claim 5
Dependent Claim
37 words
A machine according to claim 2, wherein a switch is placed between the outputs of the flip-flop columns and the associated adding circuits for enabling shifting of the connections between said flip-flop columns and the character selectors.
References Cited (Backward Citations)
US3038028A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |