JP5130755B2 - Communication equipment - Google Patents

Description

  The present invention relates to a communication device that encrypts and transmits digital data including audio data.

For example, in a communication device disclosed in Patent Document 1 below, a calling side device generates a public key using a prime number, a subscriber number, and a random number, and transmits the public key to a partner device at the start of communication.
In addition, the calling side device generates a shared secret key using the public key transmitted from the partner device, encrypts the subscriber number using the shared secret key, and uses the encrypted subscriber number as the partner number. Send to device.
The calling side device receives the subscriber number transmitted from the partner device, compares the subscriber number with the subscriber number previously transmitted to the partner device, and if both subscriber numbers match. Then, the call connection is completed, and thereafter, voice data encryption processing is performed to communicate with the partner apparatus.

In general communication systems that perform encrypted communication (call), a dedicated protocol is defined. In wireless communication, communication control is performed using a wireless control channel when performing encryption control. And so on.
That is, various types of information are exchanged by using a radio control channel other than the data channel provided for transmission of voice data until encryption communication is started.
Therefore, in order to enable an existing communication system that does not perform encryption to start encrypted communication, for example, a modification such as changing a dedicated protocol is required.
This has a great influence on the entire communication system, and the influence of development cost, verification period, etc. is immeasurable.

JP 2005-20114 (paragraph numbers [0025] to [0028], FIG. 1)

  Since the conventional communication equipment is configured as described above, the voice data encrypted communication can be started immediately after the call connection is completed, but it is necessary for the encryption process before the call connection is established. Necessary information to be exchanged with the other device. However, in a general PSTN line or the like, when a call connection is not established, information other than the subscriber number cannot be transmitted and received, and information necessary for encryption processing is exchanged with the partner device. Therefore, there is a problem that voice data communication cannot be started unless a call connection is established.

  The present invention has been made to solve the above-described problems. Even when the communication partner device does not have the voice data encryption function, the voice data can be transmitted and the call connection can be performed. An object of the present invention is to obtain a communication device that can immediately start encrypted communication or non-encrypted communication of voice data when established.

A communication device according to the present invention includes a key information adding unit that adds key information indicating a key used for encryption of audio data to the audio data, and the audio data to which the key information is added by the key information adding unit. A data exchanging means for transmitting voice data to which key information is added from a counterpart device, key information added to voice data received by the data exchanging means, and key information adding means If the comparison result by the key information comparison means for comparing the key information added to the voice data by the key information comparison means indicates a match of the key information, the voice data is encrypted using the key indicated by the key information. When the encrypted voice data is transmitted to the communication partner device and the comparison result indicates a mismatch of the key information, the voice data is transmitted to the communication partner device without encryption. And transmitting means receives the audio data transmitted from the device of the communication partner, when the comparison result by the key information comparing means indicates a match of the key information, using the key the key information indicates the encryption of the speech data And when the comparison result by the key information comparison means indicates a mismatch of the key information, the voice data receiving means for outputting the voice data without decrypting the encryption of the voice data, and the key information comparison means A specific sound generating means for generating a specific sound for notifying start of encrypted communication of voice data when the comparison result indicates a match of the key information, the voice data transmitting means for the first voice with the communication partner device; At the time of data transmission, the voice data is not encrypted .

According to the present invention, voice data to which key information indicating a key used for encryption of voice data is added is transmitted to a communication partner device, while voice data to which key information is added is received from the communication partner device. A voice data transmission unit provided with a data exchange unit and a key information comparison unit that compares the key information added to the voice data received by the data exchange unit and the key information added to the voice data by the key information addition unit; However, when the first voice data is transmitted to the communication partner device, the voice data is not encrypted, and if the comparison result by the key information comparison means indicates the coincidence of the key information, the voice using the key indicated by the key information is used. data is encrypted and transmits the audio data after encryption to the communication partner of the device, when the comparison result indicates a mismatch key information, and sends the voice data to the communication partner device without encryption, When the voice data receiving means receives the voice data transmitted from the communication partner device, and the comparison result by the key information comparing means indicates a match of the key information, the voice data is encrypted using the key indicated by the key information. When the comparison result by the key information comparison means indicates a mismatch of the key information, the voice data is output without decrypting the encryption of the voice data, and the specific sound generating means is compared with the comparison result by the key information comparison means. When the key information coincides, it is configured to generate a specific sound to notify the start of encrypted communication of the voice data, so even if the communication partner device does not have the voice data encryption function, the voice data it is possible to send, when the call connection is established immediately can start the encrypted communication or non-encrypted communication of voice data, when determining the start of encrypted communication, voice de The specific sound is generated to inform the start of the encrypted communication data, there is an effect that can be made to recognize the user that encrypted communication is started.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a communication device according to Embodiment 1 of the present invention. In the figure, an audio / AD conversion circuit 1 encodes information including voice under the direction of a radio / man machine control unit 8. Then, a process of outputting audio data that is encoded data is performed.
The audio codec unit 2 performs compression processing and encryption processing on the audio data output from the audio / AD conversion circuit 1.

The key management unit 3 manages N keys (n) (n = 1, 2,..., N) used for encrypting audio data, and a plurality of bits indicating the actually used key (n). Key number information is output to the compression processing unit 4 and the key management unit 17 of the audio decoding unit 13, and the key (n) is output to the encryption unit 5, and the encryption process of the encryption unit 5 is controlled. Perform the process.
The compression processing unit 4 performs a compression process on the audio data output from the audio / AD conversion circuit 1, adds the key number information output from the key management unit 3 to the compressed audio data, and adds the key number information. Are scrambled and output to the encryption unit 5.
The key management unit 3 and the compression processing unit 4 constitute key information adding means.

  The encryption unit 5 encrypts the audio data with the key number information output from the compression processing unit 4 at the time of transmission of the first audio data after the call connection is established under the instruction of the key management unit 3. The voice data is output to the radio channel / frame construction unit 6 without conversion, and the key management unit 3 outputs the encryption command at the time of transmission of the second and subsequent (including the second) voice data. Then, using the key (n) output from the key management unit 3, the audio data with the key number information output from the compression processing unit 4 is encrypted, and the encrypted audio data is constructed as a radio channel / frame. If the key management unit 3 outputs a non-encryption command, the audio data output from the compression processing unit 4 is not encrypted, and the audio data is transmitted to the radio channel / frame construction unit 6. Execute the process to output to.

Under the instruction of the radio / man machine control unit 8, the radio channel / frame construction unit 6 incorporates the audio data output from the encryption unit 5 into a frame of a communication channel in a radio format in accordance with a predetermined radio standard. Implement processing to build band data.
The RF circuit 7 includes, for example, a modulation circuit, an amplifier circuit, a frequency conversion circuit, an antenna, and the like. The RF circuit 7 converts baseband data constructed by the radio channel / frame construction unit 6 into radio waves, and emits the radio waves to space. Perform the process.
The radio / man machine control unit 8 performs processing for controlling operations of the audio / AD conversion circuit 1 and the radio channel / frame construction unit 6.

The RF circuit 11 includes, for example, a demodulation circuit, an amplification circuit, a frequency conversion circuit, an antenna, and the like. The RF circuit 11 receives a radio wave emitted from a communication partner device and converts the radio wave into baseband data. To do.
Under the instruction of the radio / man machine control unit 19, the radio channel / frame decomposition unit 12 decomposes the baseband data frame output from the RF circuit 11, and the voice data with the key number information is obtained from the baseband data. Perform the extraction process.

The audio decoding unit 13 performs a process of decrypting the encryption of the audio data extracted by the radio channel / frame decomposition unit 12 and a process of releasing the compression.
The encryption / decryption unit 14 encrypts the audio data extracted by the radio channel / frame decomposition unit 12 when receiving the first audio data after the call connection is established under the instruction of the key management unit 17. Without decryption, the audio data is output to the decryption processing unit 15, and when the second and subsequent (including the second) audio data is received, if the key management unit 17 outputs an encryption / decryption command, Using the key (n) output from the key management unit 17, the encryption of the audio data extracted by the frame decomposition unit 12 is decrypted, and the audio data after the decryption is output to the decryption processing unit 15 for key management. If the unit 17 outputs a non-encryption decryption command, a process of outputting the speech data to the decryption processing unit 15 is performed without decrypting the encryption of the speech data extracted by the frame decomposition unit 12.

The decryption processing unit 15 cancels the scramble in the audio data output from the encryption / decryption unit 14, extracts the key number information from the audio data, outputs the key number information to the key management unit 17, and the key number information The process of releasing the compression of the audio data from which the signal is removed and outputting it to the audio / DA conversion circuit 18 is performed.
The cipher switching sound source 16 is built in the decryption processing unit 15, and when the key management unit 17 detects the coincidence of the key number information, the audio data of the specific sound for notifying the start of the encryption communication of the audio data is transmitted to the audio / DA. Processing to output to the conversion circuit 18 is performed. The encryption switching sound source 16 constitutes a specific sound generating means.

The key management unit 17 manages N keys (n) (n = 1, 2,..., N) used for encryption / decryption of audio data, and is output from the key management unit 3 of the audio codec unit 2. The key number information output from the decryption processing unit 15 is compared, and if the two key number information match, at the time of receiving the second and subsequent (including the second) audio data, The key (n) indicated by the key number information and the encryption / decryption command are output to the encryption / decryption unit 14 and the encrypted communication start command is output to the key management unit 3 of the speech codec unit 2. If the key number information does not match, a non-encryption / decryption command is output to the encryption / decryption unit 14 at the time of receiving the second and subsequent (including the second) audio data, and the non-encrypted communication is performed. A start command is output to the key management unit 3 of the audio codec unit 2.
The key management unit 17 constitutes a key information comparison unit.

The audio / DA conversion circuit 18 performs a process of returning the audio data, which is the encoded data output from the decoding processing unit 15, to the original audio information under the instruction of the radio / man machine control unit 19.
The radio / man machine control unit 19 performs processing for controlling the operations of the radio channel / frame decomposition unit 12 and the audio / DA conversion circuit 18.

The key management unit 3, compression processing unit 4, encryption unit 5, radio channel / frame construction unit 6, RF circuit 7, RF circuit 11, radio channel / frame decomposition unit 12, encryption / decryption unit 14, and decryption processing unit 15 The key management unit 17 constitutes data exchange means.
The key management unit 3, the compression processing unit 4, the encryption unit 5, the radio channel / frame construction unit 6, and the RF circuit 7 constitute voice data transmission means.
The RF circuit 11, the radio channel / frame decomposition unit 12, the encryption / decryption unit 14, the decryption processing unit 15, and the key management unit 17 constitute an audio data receiving unit.

FIG. 2 is an explanatory diagram showing a general communication channel format in wireless communication.
FIG. 3 is an explanatory diagram excerpting a part of the configuration of the wireless device and the counterpart device of FIG. That is, in order to simplify the explanation of the operation, the audio codec unit 2 of the wireless device in FIG. However, the encryption / decryption unit 14 and the key management unit 17 may not be provided).

Next, the operation will be described.
A case will be described in which the wireless device in FIG. 1 transmits information including sound to a communication partner device and receives information including sound from the communication partner device.
The radio / man machine control unit 8 of the wireless device controls, for example, the audio / AD conversion circuit 1 and the wireless channel / frame construction unit 6 to make a call to the communication partner device and establish a call connection. An input command for information including is output to the audio / AD conversion circuit 1.
Since the process of making a call to a communication partner device and the process of establishing a call connection are well-known techniques, description thereof is omitted here.

When receiving an input command from the radio / man machine control unit 8, the audio / AD conversion circuit 1 inputs information including the user's voice, encodes the information including the voice, and converts the voice data which is the encoded data. Output to the audio codec unit 2.
Note that the audio / AD conversion circuit 1 converts, for example, information including audio into linear PCM or encoded data in the μ / law data format.

The key management unit 3 of the audio codec unit 2 manages N keys (n) (n = 1, 2,..., N) used for encryption of audio data, and N keys (n ) To select an arbitrary key (n), and output key number information of a plurality of bits indicating the key (n) to the compression processing unit 4 and the key management unit 17 of the audio decoding unit 13. An arbitrary key (n) is selected using, for example, a random number.
After the call connection is established, at the time of the first audio data transmission, it is unclear whether the communication partner device supports encryption processing, and the communication partner device performs encryption processing. Even if it is compatible, the key management unit 3 does not know what encryption key is used to encrypt the communication partner's device. To the conversion unit 5.

When receiving the audio data from the audio / AD conversion circuit 1, the compression processing unit 4 of the audio codec unit 2 performs a compression process on the audio data in order to reduce the data size of the audio data.
The compression processing unit 4 performs compression processing using, for example, a CELP method or a vocoder method.
The compression processing unit 4 adds the key number information output from the key management unit 3 to the compressed audio data, scrambles the audio data with the key number information, and outputs the scrambled data to the encryption unit 5.

  When the encryption unit 5 of the audio codec unit 2 receives a non-encryption command from the key management unit 3 at the time of transmission of the first audio data, the encryption unit 5 encrypts the audio data with key number information output from the compression processing unit 4. The voice data is output to the radio channel / frame construction unit 6 without being converted.

Under the instruction of the radio / man machine control unit 8, the radio channel / frame construction unit 6 incorporates the audio data output from the encryption unit 5 into a communication channel frame in a radio format in accordance with a predetermined radio standard, Build baseband data.
That is, the radio channel / frame construction unit 6 incorporates audio data into a communication channel frame as shown in FIG.
In FIG. 2, “R” is a burst transient response ramp time, “TCH” is a traffic channel that is a data storage area, “P” is a pilot symbol, “SW” is a synchronization word, “C” is a channel identifier, “G” "Indicates the guard time.
The audio data output from the encryption unit 5 is stored in “TCH” regardless of the presence or absence of encryption.

In the RF circuit 7, when the radio channel / frame construction unit 6 constructs baseband data, for example, an internal modulation circuit modulates the baseband data to generate a modulated wave, and an internal amplifier circuit amplifies the modulated wave. To do.
Then, an internal frequency conversion circuit converts the frequency of the modulated wave into a predetermined transmission frequency, and emits a radio wave as a modulated wave from the antenna to the space.
As a result, the communication partner device receives the radio wave emitted from the wireless device of FIG. 1 into the space.

The communication partner device generally includes a processing unit corresponding to the RF circuit 11, the wireless channel / frame decomposition unit 12 and the decoding processing unit 15 of the wireless device in FIG. When the emitted radio wave is received, the radio wave is demodulated and converted into baseband data, the baseband data frame is disassembled, and audio data with key number information is extracted from the baseband data.
If the counterpart device supports encryption processing, is it possible to extract the key number information from the voice data with the key number information and use the key (n) indicated by the key number information? Is determined.

If the communication partner device supports encryption processing, the communication partner device includes a processing unit corresponding to the voice codec unit 2, the wireless channel / frame construction unit 6 and the RF circuit 7 of the wireless device in FIG. If it is possible to use the key (n) indicated by the number information, the base number data is constructed by adding the key number information to the first sound data, and the baseband data is modulated to make the radio wave into space. discharge.
Note that when the communication partner device does not support encryption processing, or is compatible with encryption processing, it is impossible to use the key (n) indicated by the key number information. Without adding the key number information to the first sound data, baseband data is constructed from the first sound data, and the baseband data is modulated to emit radio waves into space.
Here, when it is impossible to use the key (n) indicated by the key number information, the key number information is not added to the first voice data. However, other keys that can be used are indicated. The key number information may be added to the first sound data.

When the RF circuit 11 of the wireless device in FIG. 1 receives a radio wave that is a modulated wave emitted from the communication partner device into the space, for example, an internal amplifier circuit amplifies the modulated wave and converts the internal frequency. A circuit converts the frequency of the modulated wave into an intermediate frequency.
The internal demodulation circuit demodulates the modulated wave and converts it into baseband data, and outputs the baseband data to the radio channel / frame decomposition unit 12.
The radio channel / frame decomposition unit 12 decomposes the frame of the baseband data output from the RF circuit 11 under the instruction of the radio / man machine control unit 19, and the voice data with the key number information from the baseband data. To extract.

The key management unit 17 of the audio decoding unit 13 sends a non-encryption / decryption command to the encryption / decryption unit 14 to instruct that the encryption / decryption is not performed when the first audio data is received after the call connection is established. Output.
When the encryption / decryption unit 14 of the audio decoding unit 13 receives the non-encryption decoding instruction from the key management unit 17, the encryption / decryption unit 14 performs the encryption decoding process on the audio data extracted by the radio channel / frame decomposition unit 12. The audio data is output to the decoding processing unit 15.

When receiving the audio data from the encryption / decryption unit 14, the decoding processing unit 15 of the audio decoding unit 13 releases the scramble in the audio data, extracts the key number information from the audio data, and uses the key number information as the key management unit. 17 to output.
In addition, the decryption processing unit 15 releases the compression of the audio data from which the key number information has been removed and outputs it to the audio / DA conversion circuit 18.
Under the instruction of the wireless / man machine control unit 19, the audio / DA conversion circuit 18 returns the audio data, which is the encoded data output from the decoding processing unit 15, to the original audio information and outputs the audio information. .

When the key management unit 17 of the audio decoding unit 13 receives the key number information from the decoding processing unit 15, the key management unit 17 compares the key number information with the key number information output from the key management unit 3 of the audio codec unit 2. It is determined whether or not the key number information matches.
If both key number information matches, the key management unit 17 sends an encrypted communication start command to the audio codec in order to perform encrypted communication in the second and subsequent (including the second) transmission of audio data. The data is output to the key management unit 3 of the unit 2.
Further, in order to perform encrypted communication in the reception of the second and subsequent (including the second) audio data, the key (n) indicated by the key number information and the encryption / decryption command are output to the encryption / decryption unit 14.
When the key management unit 3 of the audio codec unit 2 receives the encrypted communication start command from the key management unit 17 of the audio decoding unit 13, the encrypted communication is transmitted in the second and subsequent (including the second) transmission of audio data. Therefore, the key (n) indicated by the key number information and the encryption command are output to the encryption unit 5.

If the communication partner device does not support encryption processing, or if it is compatible with encryption processing and the key (n) indicated by the key number information cannot be used, the above-mentioned As described above, since the key number information is not added to the first audio data, the decoding processing unit 15 of the audio decoding unit 13 cannot extract the key number information from the audio data, and the key management unit 17 acquires the key number information. Cannot be compared.
In this case, since the key management unit 17 cannot recognize the coincidence of the key number information, it performs non-encrypted communication in the second and subsequent (including the second) transmission of audio data. For this reason, a start command for unencrypted communication is output to the key management unit 3 of the audio codec unit 2.
Further, in order to perform non-encrypted communication in the reception of the second and subsequent (including the second) audio data, a non-encryption / decryption command is output to the encryption / decryption unit 14.
When the key management unit 3 of the audio codec unit 2 receives an instruction to start unencrypted communication from the key management unit 17 of the audio decoding unit 13, the key management unit 3 performs non-encryption in the transmission of audio data for the second time and thereafter (including the second time). In order to perform encrypted communication, a non-encrypted command is output to the encryption unit 5.

Here, when it is impossible to use the key (n) indicated by the key number information, the communication partner device does not add the key number information to the first voice data. In some cases, key number information indicating the key is added to the first voice data.
In this case, the key management unit 17 determines that the key number information does not match, but the key number information (communication partner) output from the decryption processing unit 15 among the N keys managed. It is determined whether the key indicated by the key number information added to the device is present.
If the key indicated by the key number information output from the decryption processing unit 15 is, for example, the key (2), it exists in the managed N keys, so the second and subsequent times (including the second time) ) In the transmission / reception of voice data.
On the other hand, if it does not exist in the managed N keys, unencrypted communication is performed in the second and subsequent (including the second) audio data transmission / reception.

The key management unit 17 outputs an encrypted communication start command to the key management unit 3 of the audio codec unit 2 when performing encrypted communication in the second and subsequent (including the second) transmission of audio data. The key number information output from the decryption processing unit 15 (key number information added to the communication partner device) is output to the key management unit 3.
In addition, when performing encrypted communication in the reception of the second and subsequent (including the second) audio data, the key indicated by the key number information output from the decryption processing unit 15 and the encryption / decryption command are output to the encryption / decryption unit 14. To do.
When the key management unit 3 of the audio codec unit 2 receives the encrypted communication start command from the key management unit 17 of the audio decoding unit 13, the encrypted communication is transmitted in the second and subsequent (including the second) transmission of audio data. Therefore, the key indicated by the key number information output from the key management unit 17 and the encryption command are output to the encryption unit 5.

Next, transmission of audio data after the second time (including the second time) will be described.
When the audio / AD conversion circuit 1 inputs information including the user's voice under the instruction of the radio / man machine control unit 8, the audio / AD conversion circuit 1 encodes the information including the voice and converts the audio data which is the encoded data into the audio codec unit. Output to 2.

The key management unit 3 of the audio codec unit 2 outputs key number information indicating the key (n) to the compression processing unit 4 when receiving a command for starting encrypted communication from the key management unit 17 of the audio decoding unit 13. The key (n) and the encryption command are output to the encryption unit 5.
However, when key number information is output from the key management unit 17 of the audio decoding unit 13, the key number information is output to the compression processing unit 4, and the key indicated by the key number information and the encryption command are encrypted. Output to unit 5.
The key management unit 3 outputs a non-encrypted command to the encryption unit 5 when receiving a non-encrypted communication start command from the key management unit 17 of the audio decoding unit 13.

When receiving the audio data from the audio / AD conversion circuit 1, the compression processing unit 4 of the audio codec unit 2 performs a compression process on the audio data in order to reduce the data size of the audio data.
The compression processing unit 4 adds the key number information output from the key management unit 3 to the compressed audio data, scrambles the audio data with the key number information, and outputs the scrambled data to the encryption unit 5.
However, when performing non-encrypted communication, since the key number information output from the key management unit 3 is not output, the voice data is scrambled and encrypted without adding the key number information to the compressed voice data. To the conversion unit 5.

When the encryption unit 5 of the voice codec unit 2 receives the key (n) and the encryption command from the key management unit 3, the encryption unit 5 uses the key (n) to output the key number information output from the compression processing unit 4. The attached audio data is encrypted, and the encrypted audio data is output to the radio channel / frame construction unit 6.
When receiving a non-encryption instruction from the key management unit 3, the encryption unit 5 does not encrypt the audio data output from the compression processing unit 4, and transmits the audio data to the radio channel / frame construction unit 6. Output.

Under the instruction of the radio / man machine control unit 8, the radio channel / frame construction unit 6 incorporates the audio data output from the encryption unit 5 into a communication channel frame in a radio format in accordance with a predetermined radio standard, Build baseband data.
That is, the radio channel / frame construction unit 6 incorporates audio data into a communication channel frame as shown in FIG.

In the RF circuit 7, when the radio channel / frame construction unit 6 constructs baseband data, for example, an internal modulation circuit modulates the baseband data to generate a modulated wave, and an internal amplifier circuit amplifies the modulated wave. To do.
Then, an internal frequency conversion circuit converts the frequency of the modulated wave into a predetermined transmission frequency, and emits a radio wave as a modulated wave from the antenna to the space.
As a result, the communication partner device receives the radio wave emitted from the wireless device of FIG. 1 into the space.

Next, reception of audio data after the second time (including the second time) will be described.
When the RF circuit 11 of the wireless device receives a radio wave that is a modulated wave emitted from the communication partner device to the space, for example, an internal amplifier circuit amplifies the modulated wave, and an internal frequency conversion circuit The frequency of the modulated wave is converted to an intermediate frequency.
The internal demodulation circuit demodulates the modulated wave and converts it into baseband data, and outputs the baseband data to the radio channel / frame decomposition unit 12.
The radio channel / frame decomposition unit 12 decomposes the frame of the baseband data output from the RF circuit 11 under the instruction of the radio / man machine control unit 19 and extracts the audio data from the baseband data.

When receiving the key (n) and the encryption / decryption command from the key management unit 17, the encryption / decryption unit 14 of the audio decoding unit 13 is extracted by the wireless channel / frame decomposition unit 12 using the key (n). The encryption of the sound data is decrypted, and the sound data after the decryption is output to the decryption processing unit 15.
When receiving a non-encryption decryption command from the key management unit 17, the encryption / decryption unit 14 performs the decryption process on the speech data extracted by the radio channel / frame decomposition unit 12 without performing the decryption process of the encryption. The data is output to the decryption processing unit 15.

When receiving the audio data from the encryption / decryption unit 14, the decoding processing unit 15 of the audio decoding unit 13 releases the scramble in the audio data, releases the compression of the audio data, and outputs it to the audio / DA conversion circuit 18.
When the key management unit 17 determines that the key number information matches and determines the start of encrypted communication, the cipher switching sound source 16 of the decryption processing unit 15 has voice data of a specific sound that informs the start of encrypted communication of the voice data. Is output to the audio / DA conversion circuit 18.
Under the instruction of the radio / man machine control unit 19, the audio / DA conversion circuit 18 returns the audio data, which is the encoded data output from the decoding processing unit 15, to the original audio information, and the audio information and the specific sound Is output.

  As is apparent from the above, according to the first embodiment, the voice data to which the key information indicating the key used for encryption of the voice data is added is transmitted to the communication partner device, while the key is transmitted from the communication partner device. Data exchange means for receiving voice data to which information is added, key information for comparing key information added to voice data received by the data exchange means and key information added to voice data by the key information addition means A comparison means, and when the comparison result by the key information comparison means indicates that the key information matches, the voice data transmission means encrypts the voice data using the key indicated by the key information, and converts the encrypted voice data If the comparison result indicates that the key information does not match, the voice data is sent to the communication partner device without encryption. Even if the encryption function is not provided, the voice data can be transmitted, and when the call connection is established, the voice data encrypted communication or the non-encrypted communication can be started immediately. Play.

  Further, according to the first embodiment, when the voice data transmitted from the communication partner device is received and the comparison result by the key information comparison means indicates the coincidence of the key information, the key indicated by the key information is used. Since the encryption of the voice data is decrypted, and the comparison result by the key information comparison means indicates that the key information does not match, the voice data is output without being decrypted. Even if the communication partner device does not have the voice data encryption function, the voice data can be received and immediately after the call connection is established, the voice data is encrypted or unencrypted. There is an effect that can be started.

  Further, according to the first embodiment, when the key management unit 17 recognizes the coincidence of the key number information and determines the start of encrypted communication, a specific sound is generated to notify the start of encrypted communication of audio data. Since it comprised as mentioned above, there exists an effect which can recognize that the user started encryption communication.

It is a block diagram which shows the communication apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the general communication channel format in radio | wireless communication. It is explanatory drawing which extracted the structure of a part of radio | wireless apparatus of FIG. 1, and the apparatus of a communicating party.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Audio / AD conversion circuit, 2 Voice codec part, 3 Key management part (Key information addition means, Data exchange means, Voice data transmission means) 4 Compression processing part (Key information addition means, Data exchange means, Voice data transmission means) ) 5 Encryption section (data exchange means, voice data transmission means), 6 Radio channel / frame construction section (data exchange means, voice data transmission means), 7 RF circuit (data exchange means, voice data transmission means), 8 , 19 Wireless / man machine control unit, 11 RF circuit (data exchange unit, voice data reception unit), 12 Radio channel / frame decomposition unit (data exchange unit, voice data reception unit), 13 Voice decoding unit, 14 Cryptographic decoding unit (Data exchange means, voice data receiving means), 15 decryption processing section (data exchange means, voice data receiving means), 16 encryption switching Sound source (specific sound generating means), 17 key management section (key information comparing means, data exchanging means, audio data receiving means), 18 audio / DA conversion circuit.

Claims (2)

A key information adding means for adding key information indicating a key used for encrypting the voice data to the voice data; and transmitting the voice data to which the key information is added by the key information adding means to the device of the communication partner. Data exchange means for receiving voice data to which key information is added from the device, key information added to the voice data received by the data exchange means, and key added to the voice data by the key information addition means When the comparison result by the key information comparison means for comparing information and the key information comparison means indicates a match of the key information, the voice data is encrypted using the key indicated by the key information, and the encrypted voice data is and transmitted to the communication partner apparatus, when the comparison result indicates a mismatch key information, and audio data transmission means for transmitting to the communication partner device without encrypting the audio data, the communication partner machine If the comparison result by the key information comparison means indicates that the key information matches, the encryption of the voice data is decrypted using the key indicated by the key information, and the key information comparison is performed. If the comparison result by the means indicates that the key information does not match, the voice data receiving means for outputting the voice data without decrypting the encryption of the voice data and the comparison result by the key information comparison means indicate that the key information matches. A specific sound generating means for generating a specific sound informing the start of encrypted communication of the audio data, and the audio data transmitting means transmits the audio data at the time of the first transmission of the audio data with the communication partner device. A communication device characterized by not encrypting . 2. The data exchange means stores voice data and key information in a data storage area of a communication channel, and exchanges the voice data and key information with a communication partner device using the communication channel. The communication device described.

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