JPH03178237A - Terminal equipment for preventing leakage of privacy information - Google Patents

Abstract

PURPOSE:To secure privacy by convering a voice signal between end-end users and sending a data with no meaning at all to a transmission line so as to allow only talkers to understand the data. CONSTITUTION:Plural code conversion tables are prepared to a terminal equipment, one conversion table 10 is selected according to a decoding key and a true voice code is not transmitted to me transmission line but a code not understandable to a 3rd party is sent. Then a reception side terminal equipment decodes the code into the original voice signal according to the decoding key. In this case, the voice actually sent to a radio signal propagation space is a meaningless voice signal and then the leakage of privacy information is prevented. Thus, the leakage of a caller's privacy information is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a terminal for an exchange, and particularly to a terminal for preventing privacy leakage.

[Conventional technology]

Car phones allow calls to be made while in the car, and the convenience of the caller's ability to immediately communicate with the other party even if the other party is in the car has made it increasingly popular in society, especially in the business community. Tend. This can be said to be the result of the ideal form of a telephone that allows you to reach the other party immediately, anytime, anywhere, to have penetrated into the world of mobile devices, which was previously impossible.

[Problem to be solved by the invention]

On the other hand, in the case of a car phone, since the transmission path is wireless, calls can be intercepted and privacy cannot be completely protected. Additionally, if there is a codec in the wired section, there is a possibility that the contents of the call may be leaked to a third party.

[Means to solve the problem]

The privacy leak prevention terminal of the present invention converts an analog audio signal into an 8-bit digital code when encoding, and expresses the digital code with another 8-bit digital code based on a plurality of types of conversion tables. means, a second means for converting the 8-bit digital code on the aforementioned side into the original 8-bit digital code using a plurality of types of conversion tables during encoding, and a decoder for identifying the conversion table. The apparatus includes third means for inputting and specifying a key signal, and fourth means for transmitting the decryption key signal along with call setting information.

[Effect]

In the present invention, a plurality of code conversion tables are prepared in the terminal, one conversion table is selected according to the decoding key, and instead of transmitting true speech codes to the transmission path, codes that cannot be understood by third parties are sent. This prevents privacy leaks, and the receiving terminal restores the original audio signal according to the decryption key. In this way, the voice flowing in the wireless section is completely meaningless voice, and leakage of privacy can be prevented.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

Referring to FIG. 1 showing an embodiment of the present invention, this privacy leakage prevention terminal (I interface terminal) includes a central processing unit (CPU) 1, a main memory (MM) 2, a keyboard 3, and a privacy leakage prevention terminal (I interface terminal). A prevention setting switch 4, a privacy leak prevention release switch 5, a bus 6,
LAP-D handler (LAP-D) 7, S/T interface 8, line circuit and cooperative (C○
DEC) 9, data & conversion table 10, and handset 1
3 and a tone generator 14. Here, L
The AP-D handler 7 controls the ISDN D channel protocol. In addition, the S/T interface 8 is
It is a DN interface reference point S/T. The codec of C0DEC9 converts audio analog signals into digital signals, and vice versa, converts digital signals into audio analog signals, and the line circuit is connected to the handset 13.
1 call is supplied and end of call is monitored. Furthermore, the tone generator 14 has a ring tone of 1 busy tone.

A special sound is generated to be heard by the calling party and the called party.

Next, data & conversion table 10. Privacy leak prevention setting switch 4. Table 1, which explains how to use the privacy leak prevention release switch 5, is the data used in this embodiment. The type of conversion is displayed depending on the value. The data name ``Incoming call privacy leak prevention'' indicates whether this function is used on the receiving side, and if used, the type of conversion is displayed based on the value. In this example, values from O to 5 are assumed, and O indicates that this function is not used. Table 2 is a table showing addresses of the 8-bit code conversion table. The contents of Table 2 are selected based on the values set by the privacy leakage prevention setting switch 4, and in this example, the conversion table at address 30 is selected. Table 2 below will be referred to as "conversion table types".

Table 3 stores the address of the conversion table, and actual conversion data is stored at the address specified by this address. Table 3 will hereinafter be referred to as a "conversion table".Table 4 has 256 8-bit codes for converting the original 8-bit digital code, each in a one-to-one ratio. In this example, if the original data is O, it is sent to the other party's terminal 255. If the original data is 1, it is sent as 254 to the other party's terminal. Table 4 will be referred to as "conversion table details" below.

Next, the operation will be explained.

When the caller specifies a conversion table, he or she presses the privacy leakage prevention setting switch 4 and inputs a number corresponding to the type of conversion table using the keyboard 3. This value is written to the data name "Outgoing privacy leak prevention". The write path is keyboard 3 → bus 6 → CPUI → MM2 → data & conversion table 10. Here, the data & conversion table 10 is a memory in terms of hardware, but
Since both 0DEC9 and CPU1 are accessed, C
It is assumed that the memory is separate from MM2, which is accessed only by the PUI.

The initial value of this value is '0' when the power is turned on.

Then, when the privacy leakage prevention release switch 5 is pressed, it also becomes °O''. To cancel the privacy leakage prevention, press the privacy leakage prevention release switch 5. This writing path is the data name "Outgoing privacy". It is exactly the same as "Leak Prevention". When the CPUI detects that dialing is complete, the data name "Outgoing Privacy Leak Prevention" is displayed.
and write this value as is in the call setup information. When the receiving terminal receives the call setting information, it writes this value in the data name "Incoming call privacy leak prevention". The write path is CPUI→bus 6→data & conversion table 10. Next, when the call path is set and the called party answers, the call is started, and the calling party's voice is converted from analog to digital by the CODEC 9. After conversion, C0DEC9 reads the data name "Outgoing Privacy Leak Prevention" in Data & Conversion Table 10, determines the conversion table from this value, converts the 8-bit code value, and sends it to the called party via B channel 12. send to the person. Below is the C0DEC of the calling party.
9 is converted according to the 1-byte/1-byte conversion table and sent to the called party. When the data name "outgoing privacy leak prevention" is "'O", no conversion process is performed at all, and digital/analog conversion is performed as is. Called party's C0D
When the EC9 receives a digital signal, it reads the data name "Incoming call privacy leak prevention", and if this value is not PaO''', it reads the conversion table corresponding to that value and performs digital/analog conversion. .

When the data name "incoming call privacy leak prevention" is "'O", no conversion processing is performed and digital/analog conversion is performed as is. After the call ends, the data name "Incoming call privacy leak prevention" is changed to "Opa". By converting the voice between end users (terminals), restoring it to the original voice, and sending completely meaningless data through the transmission path, it is possible to protect privacy by allowing only the parties to understand each other. Additionally, since this function can be provided only between terminals, there is no need to change the exchange itself, making it easy to add functions6.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1...Central processing unit, 2...Main storage device, 3...
Keyboard, 4...Privacy leakage prevention setting switch, 5...Privacy leakage prevention release switch, 6.
...Bus, 7...LAP-D handler, 8...S/
T interface, 9...Line circuit and copier, 10...Data & conversion table, Engineering 1...
D channel, ... B channel, 3... handset, 4... tone generator.

Claims (1)

[Claims] a first means for converting an analog audio signal into an 8-bit digital code when encoding and expressing the digital code as another 8-bit digital code based on a plurality of types of conversion tables; converts the 8-bit digital code into the original 8-bit code using multiple types of conversion tables.
a second means for converting the bit into a digital code; a third means for inputting and specifying a decoding key signal for identifying the conversion table; and a fourth means for transmitting the decoding key signal on call setting information. A privacy leakage prevention terminal characterized by comprising means.