FR869170A - Method and devices for ensuring the secrecy of telephone communications - Google Patents

Method and devices for ensuring the secrecy of telephone communications

Info

Publication number
FR869170A
FR869170A FR869170DA FR869170A FR 869170 A FR869170 A FR 869170A FR 869170D A FR869170D A FR 869170DA FR 869170 A FR869170 A FR 869170A
Authority
FR
France
Prior art keywords
secrecy
ensuring
devices
telephone communications
telephone
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)
Inventor
Le Dr Leon Thurm
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 filed Critical
Application granted granted Critical
Publication of FR869170A publication Critical patent/FR869170A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H04K1/02—Secret communication by adding a second signal to make the desired signal unintelligible

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Near-Field Transmission Systems (AREA)
FR869170D 1939-12-22 1941-01-11 Method and devices for ensuring the secrecy of telephone communications Expired FR869170A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
BE869170X 1939-12-22

Publications (1)

Publication Number Publication Date
FR869170A true FR869170A (en) 1942-01-26

Family

ID=3882463

Family Applications (1)

Application Number Title Priority Date Filing Date
FR869170D Expired FR869170A (en) 1939-12-22 1941-01-11 Method and devices for ensuring the secrecy of telephone communications

Country Status (2)

Country Link
BE (1) BE437461A (en)
FR (1) FR869170A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1064998B (en) * 1958-01-15 1959-09-10 Telefonbau & Normalzeit Gmbh Method and device for keeping signal change currents secret during transmission

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1064998B (en) * 1958-01-15 1959-09-10 Telefonbau & Normalzeit Gmbh Method and device for keeping signal change currents secret during transmission

Also Published As

Publication number Publication date
BE437461A (en)

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