JPS5666943A - Privacy communication system - Google Patents

Privacy communication system

Info

Publication number
JPS5666943A
JPS5666943A JP14240779A JP14240779A JPS5666943A JP S5666943 A JPS5666943 A JP S5666943A JP 14240779 A JP14240779 A JP 14240779A JP 14240779 A JP14240779 A JP 14240779A JP S5666943 A JPS5666943 A JP S5666943A
Authority
JP
Japan
Prior art keywords
signal
band
cryptogram
audio signal
masking
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.)
Granted
Application number
JP14240779A
Other languages
Japanese (ja)
Other versions
JPS593909B2 (en
Inventor
Makoto Nakamura
Shigeru Asakawa
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP14240779A priority Critical patent/JPS593909B2/en
Publication of JPS5666943A publication Critical patent/JPS5666943A/en
Publication of JPS593909B2 publication Critical patent/JPS593909B2/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)

Abstract

PURPOSE:To transmit the pseudo random series signal from transmission side to reception side in cryptogram, limitting the band of said signal by the given band pass filter, to constitute it into noise shape masking signal having an envelope to similar that of the audio signal and synthesizing it with the audio signal. CONSTITUTION:The audio signal fed to an input terminal 1 is added to an adder 11 and after it is added and synthesized with the masking signal from a masking signal generating circuit 12, it is made into a cryptogram at a cryptogram circuit 13 and delivered to a transmission circuit 3 from an output terminal 2. In general, M series virtual random signal is produced in the clock of frequency fC and it is through the narrow band filter having the pass band of, for example, fC/5 or less, then noise shape signal having Gauss distribution in the amplitude can principally be obtained. By suitably selecting the characteristics of the band pass filter 123, the frequency component and the envelope change are similar to those of audio signal, and this is used as the masking signal.
JP14240779A 1979-11-02 1979-11-02 Confidential communication method Expired JPS593909B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14240779A JPS593909B2 (en) 1979-11-02 1979-11-02 Confidential communication method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14240779A JPS593909B2 (en) 1979-11-02 1979-11-02 Confidential communication method

Publications (2)

Publication Number Publication Date
JPS5666943A true JPS5666943A (en) 1981-06-05
JPS593909B2 JPS593909B2 (en) 1984-01-26

Family

ID=15314616

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14240779A Expired JPS593909B2 (en) 1979-11-02 1979-11-02 Confidential communication method

Country Status (1)

Country Link
JP (1) JPS593909B2 (en)

Also Published As

Publication number Publication date
JPS593909B2 (en) 1984-01-26

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