FR902917A - Method of scrambling spoken messages - Google Patents

Method of scrambling spoken messages

Info

Publication number
FR902917A
FR902917A FR902917DA FR902917A FR 902917 A FR902917 A FR 902917A FR 902917D A FR902917D A FR 902917DA FR 902917 A FR902917 A FR 902917A
Authority
FR
France
Prior art keywords
band
bands
inverted
speech
give
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
Other languages
French (fr)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Patelhold Patenverwertungs and Elektro-Holding AG
Original Assignee
Patelhold Patenverwertungs and Elektro-Holding AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Patelhold Patenverwertungs and Elektro-Holding AG filed Critical Patelhold Patenverwertungs and Elektro-Holding AG
Application granted granted Critical
Publication of FR902917A publication Critical patent/FR902917A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H04K1/04—Secret communication by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Complex Calculations (AREA)
  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

582,737. Secret transmission. PATELHOLD PATENTVERWERTUNGS- & ELEKTRO-HOLDING AKT.-GES. April 5, 1944, No. 6377. Convention date, April 5, 1943. [Class 40 (iv)] In a system of secret telephony wherein the speech band is converted into a number of adjacent but transposed sub-bands of which the relative widths are constantly varying, the arrangement is such that at least one subband is inverted and at least one is not inverted. As shown in Fig. 4, the speech band e0 modulates successively a fixed frequency g1 and a varying frequency g2, the lower side-band being selected in each case to give the band e2. This then modulates a pair of frequencies g3, g4 spaced by the width of the band to give an inverted double-band e3 and also another pair of frequencies g5, g6 to give an erect doubleband e5. Complementary portions e4, e6 are selected from these double-bands and combined to form a double-band e7, from which the central portion is taken and shifted to produce a final band e10 comprising four subbands of varying width, two being erect and two inverted. In another arrangement of a similar character, different transpositions of the sub-bands are obtainable by a choice of carrier frequencies at the intermediate modulation stages. One or more of the sub-bands may be retarded ih relation to the remainder of the band ; for example, the selected portion e4 may be retarded by means of a telegraphone before combination with the portion e6. The speech band may be subjected to variable attenuation before scrambling. When the arrangement is applied to a multi-channel system, several speech channels may be grouped together for the purpose of scrambling.
FR902917D 1943-04-05 1944-03-24 Method of scrambling spoken messages Expired FR902917A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH582737X 1943-04-05

Publications (1)

Publication Number Publication Date
FR902917A true FR902917A (en) 1945-09-17

Family

ID=4521608

Family Applications (1)

Application Number Title Priority Date Filing Date
FR902917D Expired FR902917A (en) 1943-04-05 1944-03-24 Method of scrambling spoken messages

Country Status (6)

Country Link
US (1) US2411206A (en)
BE (1) BE455172A (en)
CH (1) CH238926A (en)
FR (1) FR902917A (en)
GB (1) GB582737A (en)
NL (1) NL63459C (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3124748A (en) * 1964-03-10 Secret signalling systems
CH246844A (en) * 1945-09-15 1947-01-31 Patelhold Patentverwertung Method and device for obfuscating electrically transmitted voice messages.
BE473802A (en) * 1946-08-20
US2535442A (en) * 1949-07-26 1950-12-26 James L A Mclaughlin Heterodyne eliminator communication system
US2766325A (en) * 1951-09-01 1956-10-09 Itt Narrow band communication system
DE1062750B (en) * 1957-09-27 1959-08-06 Standard Elektrik Lorenz Ag Arrangement for switching over voice inverters in communication systems
DE1181749B (en) * 1960-03-31 1964-11-19 Siemens Ag Method for message encryption
DE1196713B (en) * 1962-08-30 1965-07-15 Deutsche Bundespost Procedure for voice encryption
US4068094A (en) * 1973-02-13 1978-01-10 Gretag Aktiengesellschaft Method and apparatus for the scrambled transmission of spoken information via a telephony channel
CH559483A5 (en) * 1973-06-12 1975-02-28 Patelhold Patentverwertung
CH580893A5 (en) * 1973-07-02 1976-10-15 Gretag Ag
US4058677A (en) * 1974-04-26 1977-11-15 Lear Siegler, Inc. Sound scrambling equipment
CH578807A5 (en) * 1974-11-05 1976-08-13 Patelhold Patentverwertung
DE2523828C2 (en) * 1975-05-30 1982-08-12 TE KA DE Felten & Guilleaume Fernmeldeanlagen GmbH, 8500 Nürnberg Method for obfuscating speech signals with the aid of orthogonal matrices
DE2750240C3 (en) * 1977-11-10 1981-03-26 Felten & Guilleaume Fernmeldeanlagen GmbH, 8500 Nürnberg Process for improving the reproduction quality of speech in encryption processes
US4156107A (en) * 1978-02-03 1979-05-22 Bell Telephone Laboratories, Incorporated Speech signal scrambler
US4443660A (en) * 1980-02-04 1984-04-17 Rockwell International Corporation System and method for encrypting a voice signal
US4591673A (en) * 1982-05-10 1986-05-27 Lee Lin Shan Frequency or time domain speech scrambling technique and system which does not require any frame synchronization
US5949878A (en) * 1996-06-28 1999-09-07 Transcrypt International, Inc. Method and apparatus for providing voice privacy in electronic communication systems

Also Published As

Publication number Publication date
CH238926A (en) 1945-08-31
NL63459C (en)
BE455172A (en)
GB582737A (en) 1946-11-26
US2411206A (en) 1946-11-19

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