GB582737A - System for scrambling spoken messages - Google Patents
System for scrambling spoken messagesInfo
- Publication number
- GB582737A GB582737A GB6377/44A GB637744A GB582737A GB 582737 A GB582737 A GB 582737A GB 6377/44 A GB6377/44 A GB 6377/44A GB 637744 A GB637744 A GB 637744A GB 582737 A GB582737 A GB 582737A
- Authority
- GB
- United Kingdom
- 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
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.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH582737X | 1943-04-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB582737A true GB582737A (en) | 1946-11-26 |
Family
ID=4521608
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB6377/44A Expired GB582737A (en) | 1943-04-05 | 1944-04-05 | System for 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)
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 |
-
0
- BE BE455172D patent/BE455172A/xx unknown
- NL NL63459D patent/NL63459C/xx active
-
1943
- 1943-04-05 CH CH238926D patent/CH238926A/en unknown
-
1944
- 1944-03-24 FR FR902917D patent/FR902917A/en not_active Expired
- 1944-04-05 GB GB6377/44A patent/GB582737A/en not_active Expired
- 1944-05-19 US US536233A patent/US2411206A/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
CH238926A (en) | 1945-08-31 |
FR902917A (en) | 1945-09-17 |
NL63459C (en) | |
BE455172A (en) | |
US2411206A (en) | 1946-11-19 |
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