JPS577648A - Secret communication system - Google Patents

Secret communication system

Info

Publication number
JPS577648A
JPS577648A JP8028480A JP8028480A JPS577648A JP S577648 A JPS577648 A JP S577648A JP 8028480 A JP8028480 A JP 8028480A JP 8028480 A JP8028480 A JP 8028480A JP S577648 A JPS577648 A JP S577648A
Authority
JP
Japan
Prior art keywords
signal
voice
pseudo noise
added
noise signal
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.)
Pending
Application number
JP8028480A
Other languages
Japanese (ja)
Inventor
Kenichi Sasaki
Masanori Shiojima
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.)
Oki Electric Industry Co Ltd
Original Assignee
Oki Electric Industry Co Ltd
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 Oki Electric Industry Co Ltd filed Critical Oki Electric Industry Co Ltd
Priority to JP8028480A priority Critical patent/JPS577648A/en
Publication of JPS577648A publication Critical patent/JPS577648A/en
Pending 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

Abstract

PURPOSE:To achieve secret communication without modulating a voice signal at all, by transmitting the voice signal together with an added pseudo noise signal which is known only to a sender and a receiver. CONSTITUTION:A voice signal from a voice-electricity converter 1, such as a microphone, is added by an adding circuit 4 to a pseudo noise signal from a pseudo noise signal generating circuit 3 which generates a prescribed series of codes, such as M-series codes, and the sum is transmitted via a band-pass filter 5. This transmitted signal, after an out-band noise component added by the transmission system is removed by a band-pass filter 6, is inputted, synchronizing with the pseudo noise signal in the received composite signal, to an elimination signal generating circuit 7 which generates the same pseudo noise signal as an elimination signal and a subtracting circuit 8 which subtracts the elimination signal from the composite signal, thereby eliminating the pseudo noise signal added by the transmission system. The resulting voice signal is restored to a voice by an electricity-voice converter 9 such as a speaker.
JP8028480A 1980-06-16 1980-06-16 Secret communication system Pending JPS577648A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8028480A JPS577648A (en) 1980-06-16 1980-06-16 Secret communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8028480A JPS577648A (en) 1980-06-16 1980-06-16 Secret communication system

Publications (1)

Publication Number Publication Date
JPS577648A true JPS577648A (en) 1982-01-14

Family

ID=13713965

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8028480A Pending JPS577648A (en) 1980-06-16 1980-06-16 Secret communication system

Country Status (1)

Country Link
JP (1) JPS577648A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61176409U (en) * 1985-04-23 1986-11-04
EP0760981A4 (en) * 1995-02-23 1997-01-28 Univ California Data embedding

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61176409U (en) * 1985-04-23 1986-11-04
JPH0431556Y2 (en) * 1985-04-23 1992-07-29
EP0760981A4 (en) * 1995-02-23 1997-01-28 Univ California Data embedding
EP0760981A1 (en) * 1995-02-23 1997-03-12 The Regents Of The University Of California Data embedding

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