JP2007318451A - Voice communication terminal device, voice communication control method and voice communication terminal program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the security of voice data including even the inside of a network without being involved in a deterioration of voice communication quality. <P>SOLUTION: In a transmitting side terminal 10, a transmission encryption switching processing part 10g generates an encryption switching request with prescribed timing during communication as a turning point, and a transmission call control signal control part 10h transmits the encryption switching request to a receiving side terminal 20. When a transmission silent packet detecting part 10f later continuously detects silent packets as much as a prescribed number of times, an encode processing part 10d changes an encryption key on the basis of the encryption switching request. In the receiving terminal 20, when a reception silent packet detecting part 20f continuously detects the silent packets as much as a prescribed number of times after a reception call control signal control part 20h receives the encryption switching request transmitted from the transmitting side terminal 10, a decode processing part 20c changes the encryption key on the basis of the encryption switching request by an instruction of a reception encryption switching processing part 20i. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a voice communication terminal apparatus, a voice communication control method, and a voice communication terminal program that perform voice communication by transmitting and receiving packetized voice data via a network, and more particularly, in a network without deterioration of call sound quality. In particular, the present invention relates to a voice communication terminal device, a voice communication control method, and a voice communication terminal program that can improve the security of voice data.

  In recent years, VoIP (Voice over Internet Protocol), such as IP (Internet Protocol) telephone, videophone, and video conferencing, with the spread of constant connection environments such as ADSL (Asymmetric Digital Subscriber Line) and CATV (Community Antenna TeleVision) called broadband. Voice communication systems using technology are beginning to spread. The VoIP technology is a technology for transmitting and receiving voice data via a network such as the Internet or a LAN (Local Area Network), and eliminates the need for an exchange used for communication on a conventional fixed telephone or mobile phone. It is intended to reduce communication charges. However, on the other hand, a voice communication system using VoIP technology has a high risk of wiretapping of voice data because it uses a network such as the Internet that can be easily accessed by a third party. Security measures are an issue.

  The call procedure in the voice communication system using the VoIP technology is roughly classified into signaling that establishes connection between terminals by transmitting and receiving call control signals between voice communication terminal apparatuses (hereinafter referred to as terminals) used by users. And a process of transmitting and receiving voice data between terminals in real time after establishing a connection by signaling.

  As a point at which call control signals and voice data transmitted and received in these processes are wiretapped, if the terminal is connected to a network via a wired LAN, the terminal and a home hub (or router) Between the terminal and the access point, and between the access point and the home hub when the terminal is connected via a wireless LAN. (Or a router), and a home hub (or router) and a connection destination terminal.

  With regard to security in signaling, for example, in SIP (Session Initiation Protocol) which is a typical protocol used for signaling, a call control signal (SIP control signal) transmitted and received between a terminal and a SIP server is changed to TLS ( Secure communication is realized by encryption using Transport Layer Security.

  As for security in a wireless LAN, for example, in the wireless communication system described in Patent Document 1, communication data transmitted and received between a terminal and an access point is encrypted, and further used for encryption. Security strength in wireless communication is improved by periodically switching keys.

JP-A-2005-260286

  However, in the prior art, when a terminal is connected to a network via a wired LAN, between the terminal and the home hub (or router), between the home hub (or router) and the connected terminal, Between the access point and the home hub (or router) and between the home hub (or router) and the connected terminal when the is connected via a wireless LAN, security for voice data transmitted and received in the network There is a problem that measures are not taken.

  Also, when security measures are taken by encrypting communication data with an encryption key, it is desirable to change the encryption key at an appropriate interval during communication, but communication data delays due to the load of encryption switching processing As a result, there is a problem that the sound quality of the call may be deteriorated when the encryption key is changed during the call.

  The present invention has been made to solve the above-described problems caused by the prior art, and is a voice communication terminal device capable of improving the security of voice data including the inside of a network without deteriorating call sound quality, An object is to provide a voice communication control method and a voice communication terminal program.

  In order to solve the above-described problems and achieve the object, a voice communication terminal apparatus according to the present invention is a voice communication terminal apparatus that performs voice communication by transmitting and receiving packetized voice data via a network, and is in communication In response to the predetermined encryption switching timing, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is transmitted to the communication partner. Encryption switching requesting means for transmitting to the voice communication terminal apparatus of the communication partner, and after the encryption switching information is transmitted to the voice communication terminal apparatus of the communication partner by the encryption switching requesting means, Upon receiving a packet of silent data to the terminal device, the communication that has received the encryption switching information transmitted by the encryption switching request means. First encryption switching means for changing the encryption key based on the encryption switching information in accordance with the change of the encryption key triggered by the other voice communication terminal receiving the packet of silent data; It is provided with.

  Further, the voice communication terminal device according to the present invention, in the above invention, after receiving the encryption switching information transmitted from the voice communication terminal device of the communication partner, the packet of silence data from the voice communication terminal device of the communication partner Triggered by receiving the password, the system further comprises second encryption switching means for changing the encryption key based on the encryption switching information.

  Also, in the voice communication terminal device according to the present invention, in the above invention, the first encryption switching means transmits the encryption switching information to the voice communication terminal of the communication partner by the encryption switching request means. After that, the second encryption switching means changes the encryption key when the silent data packet is continuously transmitted to the voice communication terminal device of the communication partner a predetermined number of times. After receiving the encryption switching information from the voice communication terminal device, the encryption key is changed when a silent data packet is continuously detected a predetermined number of times from the voice communication terminal device of the communication partner. And

  Also, the audio communication control method according to the present invention is an audio that performs audio communication between a first audio communication terminal device and a second audio communication terminal device by transmitting and receiving packetized audio data via a network. A communication control method, wherein the first voice communication terminal device changes an encryption key used for encryption and decryption of the voice data triggered by a predetermined encryption switching timing during communication. An encryption switching request step of generating encryption switching information and transmitting the generated encryption switching information to the second voice communication terminal device; and the first voice communication terminal device includes the encryption After the encryption switching information is transmitted to the second voice communication terminal device by the switching request step, a silence data packet is transmitted to the second voice communication terminal device. A first encryption switching step of changing an encryption key based on the encryption switching information, and the second voice communication terminal device using the encryption switching request step, the first voice communication terminal device A second encryption switching step of changing the encryption key based on the received encryption switching information when receiving the packet of silent data after receiving the encryption switching information transmitted from It is characterized by including.

  The voice communication terminal program according to the present invention is a voice communication terminal program executed by a computer that performs voice communication by transmitting and receiving packetized voice data via a network, and performs predetermined encryption switching during communication. In response to the timing, encryption switching information indicating that the encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is transmitted to the communication partner computer. And the transmission of the silent data packet to the communication partner computer after the encryption switching information is transmitted to the communication partner computer by the encryption switching request procedure. The voice of the communication partner that has received the encryption switching information transmitted by the encryption switching request procedure A first encryption switching procedure for changing the encryption key based on the encryption switching information in accordance with the change of the encryption key triggered by reception of the silent data packet by the communication terminal; It is made to perform.

  According to the present invention, the encryption switching information indicating that the encryption key used for encryption and decryption of the audio data is changed is generated at a predetermined encryption switching timing during communication, and the generated encryption Encryption switching information transmitted here, triggered by sending a packet of silence data to the voice communication terminal device of the communication partner and then sending a packet of silence data to the voice communication terminal device of the communication partner In response to the fact that the voice communication terminal of the communication partner that received the message has received a packet of silence data, the encryption key is changed based on the above-described encryption switching information. The voice quality is prevented from being deteriorated by switching the encryption during transmission / reception of silence packets, and the sound including the inside of the network is protected by encrypting the voice data. An effect that it is possible to improve the data security.

  Further, according to the present invention, after receiving the encryption switching information transmitted from the voice communication terminal device of the communication partner, the encryption is triggered when the packet of silence data is received from the voice communication terminal device of the communication partner. Since the encryption key is changed based on the switching information, when a silent state occurs during a call, the encryption key is changed at the same timing as the change of the encryption key in the other party's voice communication terminal device, resulting in a deterioration in call sound quality. The effect that the security of audio data can be improved without accompanying the above is achieved.

  Further, according to the present invention, after transmitting the encryption switching information to the communication partner voice communication terminal, the silent data packet is continuously transmitted to the communication partner voice communication terminal device a predetermined number of times. If, on the other hand, the encryption key is changed and encryption switching information is received from the voice communication terminal device of the communication partner, then a silent data packet is transmitted a predetermined number of times from the voice communication terminal device of the communication partner. Since the encryption key is changed only when it is detected continuously, it is possible to switch the encryption when the silent state continues during a call. Even when data delay occurs, there is an effect that it is possible to prevent deterioration of call sound quality.

  Further, according to the present invention, an encryption indicating that the first voice communication terminal device changes an encryption key used for encryption and decryption of voice data triggered by a predetermined encryption switching timing during communication. Generating the encryption switching information, transmitting the generated encryption switching information to the second voice communication terminal apparatus, and then transmitting a packet of silence data to the second voice communication terminal apparatus. As a trigger, the encryption key is changed based on the encryption switching information, and after the second voice communication terminal apparatus receives the encryption switching information transmitted from the first voice communication terminal apparatus, the silent data packet is changed. Since the encryption key is changed based on the received encryption switching information when it is received, the voice quality deteriorates by switching the encryption during the transmission and reception of silence packets. Preventing an effect that it is possible to improve the security of voice data, including the network by performing the encryption of the speech data.

  Exemplary embodiments of a voice communication terminal device, a voice communication control method, and a voice communication terminal program according to the present invention will be explained below in detail with reference to the accompanying drawings. In the following description, in order to make the description easy to understand, a voice notification terminal device having a function on the transmission side is referred to as a transmission side terminal, and a voice notification terminal device having a function on the reception side is described as a reception side terminal. In the following, a case will be described in which SIP is used as a protocol for signaling performed between a caller terminal and a callee terminal, and RTP (Real-time Transport Protocol) is used as a protocol for transmitting and receiving voice data.

  First, the concept of the voice notification terminal device according to the first embodiment will be described. FIG. 1 is an explanatory diagram for explaining the concept of the voice notification terminal device according to the first embodiment. As shown in the figure, the voice notification terminal device (the transmitting terminal 10 and the receiving terminal 20) transmits and receives call control signals and voice data via the SIP server 30.

  First, when the caller terminal 10 transmits a SIP “INVITE” signal in response to a caller's call request, the call control signal (“100Try” is transmitted between the caller terminal 10 and the callee terminal 20 when triggered. ”,“ 180 Ring ”,“ 200 OK ”, etc.) are exchanged, and a connection is established between both terminals ((1) shown in FIG. 1).

  After the connection is established between both terminals, a call is made between the caller and the callee, whereby the caller terminal 10 and the callee terminal 20 transmit and receive voice data (communication data) in both directions. To do. The voice data transmitted / received here is packetized by a predetermined method when transmitted / received, and the packetized voice data includes a voice packet including voice, and a silent packet not including voice. Are mixed. Further, when transmitting and receiving voice data, the calling terminal 10 and the receiving terminal 20 encrypt the voice data using the encryption key.

  For example, as shown in FIG. 1, the connection between the originating terminal 10 and the terminating terminal 20 is established, and each terminal encrypts / decrypts using the encryption key α when transmitting / receiving voice data. (2 shown in FIG. 1).

  While the voice data is being transmitted / received in this way, when the predetermined switching timing arrives, the transmitting terminal 10 sends an encryption switching request for changing the encryption key to the call control signal “INFO”. It transmits to the receiving terminal 20 using the signal. The predetermined switching timing here may be a regular timing or a random timing. Further, the encryption switching request transmitted here includes a new encryption key. For example, it is assumed that the transmission-side terminal 10 transmits an encryption switching request including the encryption key β to the reception-side terminal 20.

  Then, the receiving terminal 20 that has received the switching request transmits an encryption switching receipt response to the transmitting terminal 10 using the “INFO” signal ((3) shown in FIG. 1).

  Thereafter, the originating terminal 10 confirms the voice data to be transmitted to the terminating terminal 20 for each packet, and when detecting a silent packet a predetermined number of times, the originating terminal 10 uses the encryption key used for encryption / decryption. α is changed to β ((4) shown in FIG. 1).

  On the other hand, the receiving terminal 20 checks the received voice data for each packet, and if a silent packet is detected a predetermined number of times, the encryption key used for encryption / decryption is changed from α to β. ((5) shown in FIG. 1).

  Thereafter, the transmitting terminal 10 and the receiving terminal 20 respectively perform encryption / decryption using the encryption key β when transmitting / receiving voice data ((6) shown in FIG. 1).

  As described above, the originating terminal 10 generates an encryption switching request at a predetermined timing during communication, transmits the generated encryption switching request to the receiving terminal 20, and transmits the encryption switching request. After that, when a silent packet is continuously detected a predetermined number of times, the encryption key is changed based on the encryption switching request, and the receiving terminal 20 transmits the encryption switching request transmitted from the calling terminal 10. When a silent packet is continuously detected a predetermined number of times after receiving the encryption key, the encryption key is changed based on the received encryption switching request. Therefore, it is possible to improve the security of voice data including the inside of the network by preventing the deterioration of the voice quality of voice and encrypting the voice data.

  Next, the configuration of the transmission side terminal 10 and the reception side terminal 20 shown in FIG. 1 will be described. FIG. 2 is a functional block diagram showing the configuration of the originating side terminal 10 and the terminating side terminal 20 shown in FIG. In FIG. 2, only functional units necessary for the description of the present invention are shown, and an input / output unit and a storage unit provided in a general voice communication terminal device (for example, a mobile phone) are not shown. Omitted.

  First, the configuration of the transmitting terminal 10 will be described. As shown in FIG. 2, the originating terminal 10 includes a microphone 10a for inputting a caller's voice, a voice receiving unit 10b, a packetization processing unit 10c, an encoding processing unit 10d, and communication data transmission. Unit 10e, transmission silence packet detection unit 10f, transmission encryption switching processing unit 10g, transmission call control signal control unit 10h, and call control signal transmission unit 10i.

  The audio receiving unit 10b is a processing unit that receives audio input from the microphone 10a, digitizes the received audio, and converts it into audio data.

  The packetization processing unit 10c is a processing unit that packetizes the voice data converted by the voice reception unit 10b. Specifically, the packetization processing unit 10c divides the audio data converted by the audio receiving unit 10b into a predetermined size, and adds header information such as an IP header, a UDP header, and an RTP header to the divided audio data. By adding, packetization of voice data is performed.

  The encoding processing unit 10d is a processing unit that encrypts the voice data packetized by the packetization processing unit 10c using a predetermined encryption key. The encoding processing unit 10d changes the encryption key when a new encryption key is transmitted from the transmission encryption switching processing unit 10g, and thereafter uses the transmitted new encryption key. Encrypt audio data.

  The communication data transmitting unit 10e is a processing unit that transmits the voice data encrypted by the encoding processing unit 10d to the receiving terminal 20.

  The transmission silent packet detection unit 10f is a processing unit that detects a silent packet from the voice data converted by the packetization processing unit 10c. Specifically, the transmission silent packet detection unit 10f confirms the voice data packetized by the packetization processing unit 10c for each packet, and when it detects a silent packet continuously a predetermined number of times, A silent packet detection notification is sent to the encryption switching processing unit 10g.

  Here, the transmission silent packet detection unit 10f notifies the silent packet detection notification when the silent packet is detected continuously for a predetermined number of times, and is encrypted when the silent state continues during the call. Thus, even when a delay of voice data occurs due to the switching of encryption, it is possible to prevent deterioration of call sound quality.

  The transmission encryption switching processing unit 10g is a processing unit that performs control related to switching of an encryption key used for encryption of audio data. Specifically, the transmission encryption switching processing unit 10g generates and stores a new encryption key at a predetermined timing during communication, and generates the generated encryption key for the transmission call control signal control unit 10h. Instructs the transmission of the encryption switching request including the key.

  In addition, when a silent packet detection notification is notified from the transmission silent packet detection unit 10f, the transmission encryption switching processing unit 10g transmits the encryption key stored at that time to the encoding processing unit 10d.

  Here, the transmission encryption switching processing unit 10g generates a new encryption key at a predetermined timing during communication and encrypts the audio data by instructing to change the encryption with the generated encryption key. It is possible to dynamically switch the encryption key to be changed during a call, and to improve security against eavesdropping.

  The transmission call control signal control unit 10h is a processing unit that performs call control in the originating terminal 10 by controlling the call control signal transmission unit 10i to transmit a call control signal using the SIP protocol. For example, this transmission call control signal control unit 10h instructs the call control signal transmission unit 10i to transmit an “INVITE” signal when a call is requested by the caller. When the transmission call control signal control unit 10h is instructed to transmit an encryption switching request from the transmission encryption switching processing unit 10g, the transmission control signal control unit 10h includes an encryption key including the encryption key. The transmission of the “INFO” signal is instructed.

  The call control signal transmission unit 10i is a processing unit that transmits a call control signal to the receiving terminal 20 based on an instruction from the transmission call control signal control unit 10h. Specifically, the call control signal transmitter 10 i transmits an “INVITE” signal, an “INFO” signal, and the like to the receiving terminal 20.

  Next, the configuration of the receiving terminal 20 will be described. As shown in FIG. 2, the receiving terminal 20 includes a speaker 20a for outputting voice to the callee, a communication data receiving unit 20b, a decoding processing unit 20c, an analog processing unit 20d, and voice transmission. Unit 20e, reception silence packet detection unit 20f, call control signal reception unit 20g, reception call control signal control unit 20h, and reception encryption switching processing unit 20i.

  The communication data receiving unit 20b is a processing unit that receives audio data transmitted from the calling terminal 10.

  The decode processing unit 20c is a processing unit that decrypts the audio data received by the communication data receiving unit 20b using a predetermined encryption key. The decoding processing unit 20c changes the encryption key when a new encryption key is transmitted from the reception encryption switching processing unit 20i, and thereafter uses the transmitted new encryption key. Decodes audio data.

  The analog processing unit 20d is a processing unit that converts the audio data decoded by the decoding processing unit 20c into analog data and converts it into audio. The analog processing unit 20d adjusts the arrival order and interval of the packets based on the sequence number and time stamp of the RTP header included in the decoded voice data packet, and converts the voice data into analog data. Do.

  The audio transmission unit 20e is a processing unit that outputs the audio converted by the analog processing unit 20d to the speaker 20a.

  The reception silence packet detection unit 20f is a processing unit that detects a silence packet from the audio data decoded by the decode processing unit 20c. Specifically, the received silent packet detection unit 20f checks the voice data decoded by the decoding processing unit 20c for each packet, and if the received silent packet is detected continuously a predetermined number of times, the received silent packet detection unit 20f The silent switching processing unit 20i is notified of a silent packet detection notification.

  Here, when the reception silent packet detector 20f detects a silent packet continuously for a predetermined number of times, the reception silent packet detection unit 20f notifies the silent packet detection notification so that an incoming call is received at the same timing as the encryption key change in the caller terminal 10 By changing the encryption key of the side terminal 20, it is possible to improve the security of the voice data without deteriorating the call sound quality.

  The call control signal receiving unit 20g is a processing unit that transmits the call control signal transmitted from the originating terminal 10 to the received call control signal control unit 20h.

  The received call control signal control unit 20h is a processing unit that performs call control in the called terminal 20 based on the call control signal based on the SIP protocol received by the call control signal receiving unit 20g. For example, when the received call control signal control unit 20h receives an “INVITE” signal from the caller terminal 10, the incoming call control signal control unit 20h uses the output unit (not shown) to receive an incoming call. The process for notifying is performed. In addition, when receiving the “INFO” signal including the new encryption key, the received call control signal control unit 20h transmits the received encryption key to the reception encryption switching processing unit 20i.

  The reception encryption switching processing unit 20i is a processing unit that performs processing related to switching of an encryption key used for decryption of audio data. Specifically, the reception encryption switching processing unit 20i stores the encryption key when a new encryption key is transmitted from the reception call control signal control unit 20h.

  In addition, when a silent packet detection notification is notified from the reception silent packet detection unit 20f, the reception encryption switching processing unit 20i transmits the encryption key stored at that time to the decoding processing unit 20c.

  Next, the processing procedure of the transmitting terminal 10 and the receiving terminal 20 shown in FIG. 1 will be described. FIG. 3 is a flowchart showing a processing procedure of the originating side terminal 10 and the terminating side terminal 20 shown in FIG. As shown in the figure, the originating terminal 10 transmits a packet (voice data) encoded (encrypted) using the encryption key α to the terminating terminal 20 (step S101). Assume that the packet received from the originating terminal 10 has been decoded (decrypted) using the encryption key α (step S102).

  Although not shown, the originating terminal 10 also decodes (decrypts) the packet received from the terminating terminal 20 using the encryption key α, and the terminating terminal 20 communicates with the originating terminal 10. Assume that the packet to be transmitted is also encoded (encrypted) using the encryption key α.

  Then, when the predetermined encryption switching timing expires (step S103, Yes), the transmission-side terminal 10 generates a new encryption key β and the transmission call control signal control unit 10h. Is instructed to transmit an “INFO” signal. Then, the transmission call control signal control unit 10h controls the call control signal transmission unit 10i and transmits an “INFO” signal including the encryption key β to the terminating terminal 20 as an encryption switching request (step S104).

  When receiving terminal 20 receives the encryption switching request (step S105), call control signal receiving unit 20g transmits the received encryption switching request to received call control signal control unit 20h, and receives call control signal control. The unit 20h transmits an encryption switching receipt response to the originating terminal 10 via the call control signal transmitting unit of the terminating terminal 20 (not shown in FIG. 2) (step S106).

  When the originating terminal 10 receives the encryption switching receipt response (step S107), the call control signal receiver of the originating terminal 10 (not shown in FIG. 2) sends the received encryption switching acceptance response to the transmission call. The transmission signal is transmitted to the control signal control unit 10h, and the transmission call control signal control unit 10h instructs the transmission encryption switching processing unit 10g to prepare for changing the transmission encryption key from α to β (step S108). .

  Thereafter, when the transmission silence packet detection unit 10f continuously detects a silence packet for a predetermined number of times (step S109, Yes), the transmission encryption switching processing unit 10g encrypts the encoding terminal 10d. The transmission encryption key is changed by transmitting the encryption key β (step S110).

  On the other hand, after receiving the encryption switching receipt response in step S106, the receiving terminal 20 changes the reception encryption key from α to β with respect to the reception encryption switching processing unit 20i by the reception call control signal control unit 20h. Instructing to prepare to perform (step S111).

  Thereafter, in the receiving terminal 20, when the received silence packet detection unit 20f continuously detects a silence packet a predetermined number of times (step S112, Yes), the reception encryption switching processing unit 20i encrypts the decoding processing unit 20c. The encryption key β is transmitted to change the reception encryption key (step S113).

  In this way, the encryption key is changed in the calling terminal 10 and the receiving terminal 20, and thereafter, in the calling terminal 10, the encoding processing unit 10d encodes the packet to be transmitted using the encryption key β ( (The packet received from the receiving terminal 20 is decoded using the encryption key β) (step S114). In the receiving terminal 20, the decoding processing unit 20c decodes the received packet using the encryption key β ( The packet to be transmitted to the originating terminal 10 is encoded using the encryption key β) (step S115).

  As described above, the transmission-side terminal 10 transmits an encryption switching request using an “INFO” signal at a predetermined timing, and then changes the encryption key when a silent packet is detected a predetermined number of times. On the other hand, after the receiving terminal 20 receives the encryption switching request transmitted from the transmitting terminal 10, the encryption key is changed when a silent packet is detected a predetermined number of times. As a result, the encryption key can be changed in synchronization between the originating terminal 10 and the receiving terminal 20, and the encryption key is changed when a silent packet is detected. Without changing the encryption.

  As described above, in the first embodiment, the transmission encryption switching processing unit 10g generates an encryption switching request at a predetermined timing during communication and transmits the encryption switching request in the originating terminal 10. After the call control signal control unit 10h transmits to the receiving terminal 20 via the call control signal transmission unit 10i and transmits the encryption switching request, the transmission silence packet detection unit 10f continues the silence packets a predetermined number of times. Then, the encoding processing unit 10d changes the encryption key based on the encryption switching request. In the receiving terminal 20, after the received call control signal control unit 20h receives the encryption switching request transmitted from the calling terminal 10 via the call control signal receiving unit 20g, the received silent packet detecting unit 20f When packets are continuously detected a predetermined number of times, the decoding processing unit 20c changes the encryption key based on the encryption switching request according to the instruction of the reception encryption switching processing unit 20i. The voice quality can be prevented from being deteriorated by switching the encryption, and the security of the voice data including the inside of the network can be improved by encrypting the voice data.

  In the first embodiment, the caller terminal 10 transmits an encryption switch request including the encryption key to the callee terminal 20. However, instead of the encryption key, for example, encryption is performed. Index information for uniquely identifying the key may be transmitted. In this case, information in which the encryption key and the index are associated with each other is stored in advance in the storage units of the transmission-side terminal 10 and the reception-side terminal 20 that are not illustrated. Then, the receiving terminal 20 acquires an encryption key corresponding to the index information included in the encryption switching request received from the calling terminal 10 from the stored encryption keys, and acquires the acquired encryption key To perform encryption and decryption. Thereby, even when the encryption switching request transmitted from the originating terminal 10 is wiretapped, the encryption key is not specified, so that stronger security can be established for a third party.

  By the way, in the first embodiment, the transmitting terminal 10 transmits an encryption switching request using the “INFO” signal at a predetermined timing, and the receiving terminal 20 continuously transmits a silent packet for a predetermined number of times. The case where the encryption key is changed based on the received encryption switching request when detected is described. However, the present invention is not limited to this, and the originating terminal does not use the SIP “INFO” signal, and does not use a packet including data of a fixed pattern uniquely associated with each encryption key. It may be used as an encryption switching request.

  Therefore, in the following, a case where the transmission side terminal transmits an encryption switching request using a packet including fixed pattern data will be described as a second embodiment.

  First, the concept of the voice notification terminal device according to the second embodiment will be described. FIG. 4 is an explanatory diagram for explaining the concept of the voice notification terminal device according to the second embodiment. As shown in the figure, the voice notification terminal devices (the transmitting terminal 60 and the receiving terminal 70) transmit and receive call control signals and voice data via the SIP server 30.

  First, when the calling terminal 60 transmits an “INVITE” signal in response to a call request from the caller, a call control signal (“100Try”, “100” between the calling terminal 60 and the receiving terminal 70 is triggered by this. 180 Ring "," 200 OK ", etc.) are exchanged, and a connection is established between both terminals ((7) shown in FIG. 4).

  After the connection is established between both terminals, a call is made between the caller and the callee, whereby the caller terminal 60 and the callee terminal 70 transmit and receive voice data (communication data) in both directions. To do. The voice data transmitted / received here is packetized by a predetermined method when transmitted / received, and the packetized voice data includes a voice packet including voice, and a silent packet not including voice. Are mixed. Further, when transmitting and receiving voice data, the calling terminal 60 and the receiving terminal 70 encrypt the voice data using the encryption key.

  For example, as shown in FIG. 4, the connection between the originating terminal 60 and the terminating terminal 70 is established, and each terminal encrypts / decrypts using the encryption key α when transmitting / receiving voice data. (8 shown in FIG. 4).

  When voice data is being transmitted and received in this manner, the originating terminal 60 starts detecting silence packets when a predetermined switching timing arrives, and continuously detects silence packets a predetermined number of times. In this case, one of the silent packets is replaced with a packet including data of a fixed pattern for encryption switching determined in advance and transmitted to the receiving terminal 70 ((9 shown in FIG. 4). )). The predetermined switching timing here may be a regular timing or a random timing.

  In addition, a plurality of fixed pattern data used here are prepared in advance, and each is associated with a unique encryption key. Then, each of the sending terminal 60 and the receiving terminal 70 stores in advance information in which fixed pattern data and an encryption key are associated with each other. Hereinafter, a packet including the fixed pattern data is referred to as an encryption switching packet.

  After transmitting the encryption switching packet, the originating terminal 60 changes the encryption key used so far with the encryption key associated with the fixed pattern data included in the encryption switching packet. . For example, if the encryption key β is associated with the fixed pattern data included in the transmitted encryption switching packet, the originating terminal 60 changes the encryption key used so far from α to β. ((10) shown in FIG. 4).

  On the other hand, the receiving terminal 70 that has received the encryption switching packet replaces the received encryption switching packet with a silent packet and changes the encryption key used so far from α to β (shown in FIG. 4 ( 11)).

  Thereafter, the transmitting terminal 60 and the receiving terminal 70 respectively perform encryption / decryption using the encryption key β when transmitting / receiving voice data ((12) shown in FIG. 4).

  In this way, when the originating terminal 10 has detected a silent packet continuously for a predetermined number of times after a predetermined timing during communication, the silent packet is encrypted including fixed pattern data. The switch packet is replaced with the packet and transmitted to the receiving terminal 20, and the encryption key is changed based on the data of the fixed pattern, and the receiving terminal 20 transmits the encrypted switching packet transmitted from the calling terminal 10. When the message is received, the encryption key is changed based on the fixed pattern data included in the received encryption switching packet, so the voice quality is prevented from being deteriorated by switching the encryption during the transmission and reception of the silent packet. In addition, by encrypting the voice data, it is possible to improve the security of the voice data including in the network. In addition, since the encryption switching packet is transmitted by replacing the silent packet, the encryption can be switched without increasing the traffic amount.

  Next, the configuration of the transmitting terminal 60 and the receiving terminal 70 shown in FIG. 4 will be described. FIG. 5 is a functional block diagram showing the configuration of the originating side terminal 60 and the terminating side terminal 70 shown in FIG. In FIG. 5, only functional units necessary for the description of the present invention are shown, and an input / output unit and a storage unit provided in a general voice communication terminal device (for example, a mobile phone) are not shown. Omitted. Also, for convenience of explanation, functional units that play the same functions as the respective units shown in FIG.

  First, the configuration of the transmission side terminal 60 will be described. As shown in FIG. 4, the calling terminal 60 includes a microphone 10a for inputting a caller's voice, a voice receiving unit 10b, a packetization processing unit 10c, an encoding processing unit 60d, and communication data transmission. Unit 10e, transmission silent packet detection unit 60f, transmission encryption switching processing unit 60g, transmission call control signal control unit 10h, call control signal transmission unit 10i, and encryption switching pattern switching unit 60j.

  The encoding processing unit 60d is a processing unit that encrypts the voice data packetized by the packetization processing unit 10c using a predetermined encryption key. The encoding processing unit 60d changes the encryption key when a new encryption key is transmitted from the encryption switching pattern replacement unit 60j, and thereafter uses the transmitted new encryption key. Encrypt audio data. In addition, when fixed pattern data is transmitted from the encryption switching pattern replacement unit 60j, the encoding processing unit 60d selects one of the silent packet audio data (silent audio data) input from the packetization processing unit 10c. Is replaced with the transmitted data of the fixed pattern, and encryption is performed. The fixed pattern data will be described later together with the encryption switching pattern replacement unit 60j.

  Here, since the encoding processing unit 60d transmits a packet including data of a fixed pattern instead of an encryption key as an encryption switching request, the encryption switching request transmitted from the originating terminal 10 is transmitted by a third party. Even when intercepted, since the encryption key is not specified, stronger security against eavesdropping can be established.

  Here, the encoding processing unit 60d replaces one silence packet with a packet (encryption switching packet) including fixed pattern data, but encrypts a predetermined number of silence packets respectively. It may be replaced with a switching packet. Thereby, it is possible to reduce the influence on the encryption switching process when the encryption switching packet is lost due to a communication failure or the like.

  The transmission silence packet detection unit 60f is a processing unit that detects a silence packet from the voice data converted by the packetization processing unit 10c. Specifically, the transmission silence packet detection unit 60f confirms the voice data packetized by the packetization processing unit 10c for each packet, and triggered by the silent packet confirmation instruction from the transmission encryption switching processing unit 60g. When silent packets are detected continuously a predetermined number of times from the trigger, a silent packet detection notification is sent to the transmission encryption switching processing unit 60g.

  The transmission encryption switching processing unit 60g is a processing unit that performs control related to switching of an encryption key used for encryption of audio data. Specifically, the transmission encryption switching processing unit 60g instructs the transmission silent packet detection unit 60f to confirm the silent packet at a predetermined timing during communication. When the silent packet detection notification is notified from the silent packet detection unit 60f, the transmission encryption switching processing unit 60g instructs the encryption switching pattern replacement unit 60j to perform encryption switching.

  The encryption switching pattern replacement unit 60j is a processing unit that extracts fixed pattern data for encryption switching and transmits a new encryption key to the encoding processing unit 60d. Specifically, the encryption switching pattern replacement unit 60j receives a plurality of fixed pattern data stored in a storage unit (not shown) triggered by an encryption switching instruction from the transmission encryption switching processing unit 60g. Arbitrary data is extracted from the inside. Here, in the storage unit, information in which a plurality of fixed pattern data is associated with an encryption key unique to each piece of data is stored in advance. Then, the encryption switching pattern replacement unit 60j transmits the extracted fixed pattern data and the encryption key associated with the data to the encoding processing unit 60d.

  Next, the configuration of the receiving terminal 70 will be described. As shown in FIG. 2, the receiving terminal 70 includes a speaker 20a for outputting voice to the recipient, a communication data receiving unit 20b, a decoding processing unit 20c, and an encryption switching fixed pattern detecting unit 70j. , A silent packet insertion unit 70k, an analogization processing unit 70d, a voice transmission unit 20e, a call control signal reception unit 20g, a reception call control signal control unit 20h, and a reception encryption switching processing unit 70i.

  The encryption switching fixed pattern detection unit 70j is a processing unit that detects a packet (encryption switching packet) including fixed pattern data from the audio data decoded by the decoding processing unit 20c. Specifically, the encryption switching fixed pattern detection unit 70j confirms the voice data decrypted by the decoding processing unit 20c for each packet, and the encryption switching packet is inserted into the reception encryption switching processing unit 70i and the silent packet insertion. The packet other than the encryption switching packet is transmitted to the analog processing unit 70d.

  The silent packet insertion unit 70k is a processing unit that replaces the encryption switching packet transmitted from the encryption switching fixed pattern detection unit 70j with a silent packet. Specifically, when the encryption switching packet is transmitted from the encryption switching fixed pattern detection unit 70j, the silence packet insertion unit 70k generates a silence packet and transmits the generated silence packet to the analog processing unit 70d. .

  The analog processing unit 70d is a processing unit that converts the voice data transmitted from the encryption switching fixed pattern detection unit 70j and the silent packet insertion unit into analog data and converts it into voice.

  The reception encryption switching processing unit 70i is a processing unit that performs processing related to switching of an encryption key used for decryption of audio data. Specifically, when receiving the encryption switching packet from the encryption switching fixed pattern detecting unit 70j, the reception encryption switching processing unit 70i stores a plurality of fixed pattern data stored in a storage unit (not shown). The encryption key corresponding to the fixed pattern data included in the received encryption switching packet is extracted from the inside. Here, in the storage unit, the same information as the fixed pattern data and the encryption key information stored in the storage unit of the transmitting terminal 60 is stored. Then, the reception encryption switching processing unit 70i transmits the extracted encryption key to the decoding processing unit 20c.

  Here, the reception encryption switching processing unit 70i instructs the change of the encryption key in response to the reception of the encryption switch packet, so that the incoming side is synchronized with the change of the encryption key in the transmission side terminal 60. The encryption key of the terminal 70 can be changed.

  Next, a processing procedure of the transmission side terminal 60 and the reception side terminal 70 shown in FIG. 4 will be described. FIG. 6 is a flowchart showing a processing procedure of the originating side terminal 60 and the terminating side terminal 70 shown in FIG. As shown in the figure, the transmitting terminal 60 transmits a packet (voice data) encoded (encrypted) using the encryption key α to the receiving terminal 70 (step S201). Assume that the packet received from the originating terminal 60 has been decoded (decrypted) using the encryption key α (step S202).

  Although not shown, the originating terminal 60 also decodes (decrypts) the packet received from the terminating terminal 70 using the encryption key α, and the terminating terminal 70 communicates with the originating terminal 60. Assume that the packet to be transmitted is also encoded (encrypted) using the encryption key α.

  Then, when the predetermined encryption switching timing expires, the transmission-side terminal 60 starts the silent packet detection by the transmission silent packet detection unit 60f triggered by a silent packet confirmation instruction from the transmission encryption switching processing unit 60g, When a silent packet is detected continuously a predetermined number of times (Yes in step S203), the transmission encryption switching processing unit 60g instructs the encryption switching pattern replacement unit 60j to perform encryption switching.

  Then, the encryption switching pattern replacement unit 60j transmits the fixed pattern data and the encryption key associated with the fixed pattern data to the encoding processing unit 60d. Here, it is assumed that the encryption switching pattern replacement unit 60j transmits the fixed pattern data corresponding to the encryption key β and the encryption key β. (Step S204).

  Upon receiving the fixed pattern data and the encryption key β, the encoding processing unit 60d replaces the silent packet with the encryption switching packet including the received fixed pattern data and transmits it to the receiving terminal 70 (step S204). ), The transmission encryption key is changed from α to β (step S205).

  On the other hand, when the receiving terminal 70 receives the encryption switching packet transmitted in step S204, the encryption switching fixed pattern detection unit 70j receives the encryption switching packet, receives the encryption switching processing unit 70i, and the silent packet insertion unit. Send to 70k.

  Then, the reception encryption switching processing unit 70i that has received the encryption switching packet extracts the encryption key β and transmits it to the decoding processing unit 20c, and the decoding processing unit 20c that receives this extracts the received encryption key as α. Is changed from β to β (step S207). In addition, the silent packet insertion unit 70k that has received the encryption switching packet generates a silent packet and transmits it to the analog processing unit 70d (step S208). As a result, the silent packet replaced with the encryption switching packet is restored and output to the speaker 20a via the voice transmission unit 20e.

  In this way, the encryption key is changed in the originating terminal 60 and the terminating terminal 70, and thereafter, in the originating terminal 60, the encoding processing unit 60d encodes the packet to be transmitted using the encryption key β ( The packet received from the receiving terminal 70 is decoded using the encryption key β) (step S209). In the receiving terminal 70, the decoding processing unit 20c decodes the received packet using the encryption key β (step S209). The packet to be transmitted to the originating terminal 60 is encoded using the encryption key β) (step S210).

  In this way, when the originating side terminal 60 detects a silent packet a predetermined number of times after a predetermined timing has arrived, the detected silent packet is replaced with an encryption switching packet and transmitted to the terminating side terminal 70. And change the encryption key. On the other hand, when the receiving terminal 70 receives the encryption switching packet transmitted from the calling terminal 60, it changes the encryption key based on the fixed pattern data included in the encryption switching packet. As a result, it is possible to change the encryption key in synchronization between the sending terminal 60 and the receiving terminal 70, and the encryption key is changed when a silent packet is detected, resulting in a deterioration in call sound quality. Without changing the encryption.

  As described above, in the second embodiment, after the predetermined timing during communication has arrived at the transmitting side terminal 60, the transmission silent packet detector 60f continuously detects the silent packets a predetermined number of times. As an opportunity, in response to an instruction from the transmission encryption switching processing unit 60g, the encryption switching pattern replacement unit 60j and the encoding processing unit 60d replace the silent packet with the encryption switching packet including the data of the fixed pattern to the receiving terminal 70. Further, the encoding processing unit 60d changes the encryption key based on the fixed pattern data. Based on the fixed pattern data included in the encryption switching packet detected by the encryption switching fixed pattern detection unit 70j when the receiving terminal 70 receives the encryption switching packet transmitted from the calling terminal 60. The decoding processing unit 20c changes the encryption key in accordance with an instruction from the reception encryption switching processing unit 70i. Therefore, the voice quality is prevented from being deteriorated by switching the encryption during transmission / reception of the silent packet. By performing the encryption of the voice data, the security of the voice data including the inside of the network can be improved.

  In the second embodiment, since the encryption switching packet is transmitted by replacing the silent packet, the encryption can be switched without increasing the network traffic amount.

  In the first and second embodiments, for convenience of explanation, the voice notification terminal device having the function of the calling side is referred to as the calling side terminal, and the voice notification terminal device having the function of the receiving side is described as the receiving side terminal. However, the voice communication terminal device according to the present invention has both functions of the transmission side and the reception side, and can transmit and receive voice data to and from other voice communication terminal devices.

  In the first and second embodiments, the voice communication terminal apparatus has been described. However, by realizing the configuration of the voice communication terminal apparatus with software, a voice communication terminal program having the same function can be obtained. A computer that executes this voice communication terminal program will be described.

  FIG. 7 is a functional block diagram illustrating the configuration of a computer that executes the voice communication terminal program according to the first and second embodiments. As shown in the figure, the computer 100 includes a RAM 110, a CPU 120, an HDD 130, a LAN interface 140, an input / output interface 150, and a DVD drive 160.

  The RAM 110 is a memory that stores a program, a program execution result, and the like. The CPU 120 is a central processing unit that reads a program from the RAM 110 and executes the program.

  The HDD 130 is a disk device that stores programs and data, and the LAN interface 140 is an interface for connecting the computer 100 to another computer via a network.

  The input / output interface 150 is an interface for connecting an input device such as a mouse or a keyboard and a display device, and the DVD drive 160 is a device for reading / writing a DVD.

  The voice communication terminal program 111 executed in the computer 100 is stored in the DVD, read from the DVD by the DVD drive 160, and installed in the computer 100.

  Alternatively, the voice communication terminal program 111 is stored in a database or the like of another computer system connected via the LAN interface 140, read out from these databases, and installed in the computer 100.

  The installed voice communication terminal program 111 is stored in the HDD 130, read into the RAM 110, and executed by the CPU 120 as the voice communication terminal process 121.

(Supplementary note 1) A voice communication terminal device that performs voice communication by transmitting and receiving packetized voice data via a network,
In response to a predetermined encryption switching timing during communication, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is Encryption switching request means for transmitting to the voice communication terminal device of the communication partner;
After the encryption switching information is transmitted to the voice communication terminal device of the communication partner by the encryption switching request unit, the packet of silence data is transmitted to the voice communication terminal device of the communication partner. In response to the fact that the voice communication terminal of the communication partner receiving the encryption switching information transmitted by the encryption switching request means has received the silent data packet, the encryption switching is changed. First encryption switching means for changing the encryption key based on the information;
A voice communication terminal device comprising:

(Supplementary Note 2) After receiving the encryption switching information transmitted from the voice communication terminal device of the communication partner, the encryption switching information is triggered by receiving a packet of silence data from the voice communication terminal device of the communication partner. The voice communication terminal device according to appendix 1, further comprising second encryption switching means for changing the encryption key based on the above.

(Supplementary Note 3) After the encryption switching information is transmitted to the communication partner voice communication terminal by the encryption switch request unit, the first encryption switching unit sends the first communication switch to the communication partner voice communication terminal device. Change the encryption key triggered by the fact that the packet of silent data has been transmitted continuously a predetermined number of times,
The second encryption switching unit continuously detects a silent data packet from the communication partner voice communication terminal device a predetermined number of times after receiving the encryption switch information from the communication partner voice communication terminal device. The voice communication terminal device according to appendix 2, wherein the encryption key is changed in response to this.

(Additional remark 4) The said encryption switching request | requirement means is a voice communication terminal of a communicating party triggered by having detected the packet of silence data for the predetermined number of times continuously, after the predetermined encryption switching timing during communication arrives Send encryption switch information to the device,
The first encryption switching unit changes the encryption key when encryption switching information is transmitted to the voice communication terminal device of the communication partner by the encryption switching request unit,
The voice communication terminal apparatus according to appendix 2, wherein the second encryption switching means changes the encryption key when receiving the encryption switching information from the terminal apparatus of the communication partner.

(Supplementary Note 5) The encryption switching request unit generates encryption switching information including an identifier for uniquely identifying an encryption key, and transmits the generated encryption switching information to a voice communication terminal device of a communication partner. Send
The first encryption switching means changes an encryption key used for the encryption and decryption with an encryption key corresponding to an identifier included in the encryption switching information,
The second encryption switching unit changes an encryption key used for the encryption and decryption with an encryption key corresponding to an identifier included in the encryption switching information transmitted from the voice terminal device of the communication partner. The voice communication terminal device according to any one of supplementary notes 1 to 4, characterized in that:

(Supplementary Note 6) Call control between voice communication terminal devices is performed using SIP (Session Initiation Protocol),
4. The voice communication terminal apparatus according to appendix 3, wherein the encryption switching request unit transmits the encryption switching information using an INFO signal which is a SIP call control signal.

(Supplementary Note 7) The encryption switching request unit generates encryption switching information including fixed pattern data uniquely associated in advance for each encryption key, and transmits a packet including the generated encryption switching information. Replacing the silent data packet and transmitting to the voice communication terminal device of the communication partner,
The first encryption switching unit is an encryption key corresponding to fixed pattern data included in the encryption switching information generated by the encryption switching request unit, and uses an encryption key used for the encryption and decryption. change,
The second encryption switching means is an encryption key corresponding to fixed pattern data included in the encryption switching information transmitted from the voice terminal device of the communication partner, and an encryption key used for the encryption and decryption. The voice communication terminal device according to appendix 4, wherein the voice communication terminal device is changed.

(Supplementary Note 8) The encryption switching requesting unit generates encryption switching information including the fixed pattern data, and each of the detected plurality of silent data packets including the generated packet including the encryption switching information. The voice communication terminal apparatus according to appendix 7, wherein the voice communication terminal apparatus replaces the fixed pattern data packet and transmits the packet as the encryption switching information.

(Supplementary note 9) A voice communication control method for performing voice communication between a first voice communication terminal device and a second voice communication terminal device by transmitting and receiving packetized voice data via a network,
The first voice communication terminal device is
In response to a predetermined encryption switching timing during communication, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is An encryption switching requesting step for transmitting to the second voice communication terminal device;
The first voice communication terminal device is
Triggered by sending a packet of silent data to the second voice communication terminal device after the encryption switch information was sent to the second voice communication terminal device in the encryption switch request step. A first encryption switching step of changing an encryption key based on the encryption switching information;
The second voice communication terminal device is
Based on the received encryption switching information when receiving the packet of the silent data after receiving the encryption switching information transmitted from the first voice communication terminal device in the encryption switching request step. A second encryption switching step for changing the encryption key,
A voice communication control method comprising:

(Supplementary Note 10) A voice communication terminal program executed by a computer that performs voice communication by transmitting and receiving packetized voice data via a network,
In response to a predetermined encryption switching timing during communication, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is An encryption switching request procedure to be transmitted to a communication partner computer;
After the encryption switching information is transmitted to the communication partner computer by the encryption switching request procedure, the encryption switching request procedure is triggered by transmitting a packet of silent data to the communication partner computer. The encryption key is changed based on the encryption switching information in response to the voice communication terminal of the communication partner receiving the encryption switching information transmitted by changing the encryption key triggered by receiving the silent data packet. The first encryption switching procedure to change
Is executed by the computer.

  As described above, the voice communication terminal device, the voice communication control method, and the voice communication terminal program according to the present invention are useful for voice communication performed by transmitting and receiving packetized voice data via a network. This is suitable for improving the security of audio data including the network without degradation of sound quality.

It is explanatory drawing for demonstrating the concept of the audio | voice notification terminal device which concerns on the present Example 1. FIG. It is a functional block diagram which shows the structure of the transmission side terminal and receiving side terminal which were shown in FIG. It is a flowchart which shows the process sequence of the transmission side terminal and receiving side terminal which were shown in FIG. It is explanatory drawing for demonstrating the concept of the audio | voice notification terminal device which concerns on the present Example 2. FIG. FIG. 5 is a functional block diagram illustrating configurations of a transmission side terminal and a reception side terminal illustrated in FIG. 4. It is a flowchart which shows the process sequence of the transmission side terminal and receiving side terminal which were shown in FIG. It is a functional block diagram which shows the structure of the computer which performs the audio | voice communication terminal program which concerns on the present Examples 1 and 2. FIG.

Explanation of symbols

10, 60 Originating terminal 10a Microphone 10b Audio receiving unit 10c Packetization processing unit 10d, 60d Encoding processing unit 10e Communication data transmission unit 10f, 60f Transmission silent packet detection unit 10g, 60g Transmission encryption switching processing unit 10h Transmission call control signal Control unit 10i Call control signal transmission unit 20, 70 Termination side terminal 20a Speaker 20b Communication data reception unit 20c Decoding processing unit 20d, 70d Analog processing unit 20e Voice transmission unit 20f Reception silent packet detection unit 20g Call control signal reception unit 20h Reception Call control signal control unit 20i, 70i Reception encryption switching processing unit 30 SIP server 60j Encryption switching pattern replacement unit 70j Encryption switching fixed pattern detection unit 70k Silent packet insertion unit 100 Computer 110 RAM
111 Voice communication terminal program 120 CPU
121 Voice communication terminal process 130 HDD
140 LAN interface 150 I / O interface 160 DVD drive

Claims (5)

A voice communication terminal device that performs voice communication by transmitting and receiving packetized voice data via a network,
In response to a predetermined encryption switching timing during communication, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is Encryption switching request means for transmitting to the voice communication terminal device of the communication partner;
After the encryption switching information is transmitted to the voice communication terminal device of the communication partner by the encryption switching request unit, the packet of silence data is transmitted to the voice communication terminal device of the communication partner. In response to the fact that the voice communication terminal of the communication partner receiving the encryption switching information transmitted by the encryption switching request means has received the silent data packet, the encryption switching is changed. First encryption switching means for changing the encryption key based on the information;
A voice communication terminal device comprising:   After receiving the encryption switching information transmitted from the voice communication terminal device of the communication partner, and receiving a packet of silence data from the voice communication terminal device of the communication partner, the encryption is performed based on the encryption switching information. The voice communication terminal apparatus according to claim 1, further comprising second encryption switching means for changing a key. After the encryption switching information is transmitted to the communication partner voice communication terminal by the encryption switch requesting unit, the first encryption switching unit transmits silent data to the communication partner voice communication terminal device. Change the encryption key triggered by sending the packet continuously a predetermined number of times,
The second encryption switching unit continuously detects a silent data packet from the communication partner voice communication terminal device a predetermined number of times after receiving the encryption switch information from the communication partner voice communication terminal device. The voice communication terminal device according to claim 2, wherein the encryption key is changed in response to this. A voice communication control method for performing voice communication between a first voice communication terminal device and a second voice communication terminal device by transmitting and receiving packetized voice data via a network,
The first voice communication terminal device is
In response to a predetermined encryption switching timing during communication, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is An encryption switching requesting step for transmitting to the second voice communication terminal device;
The first voice communication terminal device is
Triggered by sending a packet of silent data to the second voice communication terminal device after the encryption switch information was sent to the second voice communication terminal device in the encryption switch request step. A first encryption switching step of changing an encryption key based on the encryption switching information;
The second voice communication terminal device is
Based on the received encryption switching information when receiving the packet of the silent data after receiving the encryption switching information transmitted from the first voice communication terminal device in the encryption switching request step. A second encryption switching step for changing the encryption key,
A voice communication control method comprising: A voice communication terminal program executed by a computer that performs voice communication by transmitting and receiving packetized voice data via a network,
In response to a predetermined encryption switching timing during communication, encryption switching information indicating that an encryption key used for encryption and decryption of the audio data is changed is generated, and the generated encryption switching information is An encryption switching request procedure to be transmitted to a communication partner computer;
After the encryption switching information is transmitted to the communication partner computer by the encryption switching request procedure, the encryption switching request procedure is triggered by transmitting a packet of silent data to the communication partner computer. The encryption key is changed based on the encryption switching information in response to the voice communication terminal of the communication partner receiving the encryption switching information transmitted by changing the encryption key triggered by receiving the silent data packet. The first encryption switching procedure to change
Is executed by the computer.

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