KR102545276B1 - Communication terminal based group call security apparatus and method - Google Patents

Abstract

A technology related to a communication terminal-based group call security apparatus and method is disclosed.
A group call security device based on a communication terminal according to an embodiment of the present invention performs security of a group call based on a communication terminal participating in a group call, and recalls participants participating in the group call using the communication terminal. a group call information receiving unit for receiving identification information for distinguishing participants from other participants in a group call from a predetermined system providing a group call security service for each group call session; a mark signal generator for generating a mark signal for an audio watermark using the participant discrimination information; and a watermarking unit processing group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transmitting the secure voice signal to a voice output unit of the communication terminal. Including, even if the sound source file in which the voice of the group call is recorded is leaked, the source file's outflow path can be traced, while maintaining the call quality and guaranteeing a high level of watermark detection rate, Prevent leakage of unique personal information and overload of call service system.

Description

Communication terminal based group call security apparatus and method

The present invention relates to a communication terminal-based group call security apparatus and method, and more particularly, even when a sound source file in which a group call voice is recorded is leaked, it is possible to track the outflow path of the sound source file so as to prevent group call It relates to a communication terminal-based group call security apparatus and method for securing security.

In general, a group call refers to a multiparty call method in which a plurality of talkers participate in one call session, such as a conference call. Recently, the penetration rate of mobile communication terminals such as smartphones has increased, and national organizations and many companies have introduced business mobile solutions such as BYOD (Bring Your Own Device) and UC (Unified Communication) to conduct remote meetings through group calls. As such, interest in and requests for technology for ensuring the security of group calls are rapidly increasing.

However, as disclosed in Korean Patent Registration No. 10-1125942 and Korean Patent Publication No. 10-2011-0046922, existing technologies for performing audio watermarking to protect the copyright of digital audio contents However, there is a problem that cannot be applied to group call service as it is . That is, call voice is not premised on being recorded on a medium like general audio content, but occurs and disappears in real time. Therefore, in order to apply audio watermarking technology to a call service having such real-time characteristics, the call quality must be adversely affected. It should be possible to perform audio watermarking on a call voice in real time without going crazy, and it should be possible to guarantee a watermark detection rate in the watermarked call voice. Therefore, existing techniques for performing audio watermarking in a static environment cannot be applied to a call service.

In particular, in order to secure the security of a group call involving multiple participants, different watermarking must be performed for each voice output from the communication terminal of each participant. Not applicable to call services.

In addition, if existing technologies for performing audio watermarking using fixed personal information are to be applied to group calls, there is a problem in that enormous computing resources must be provided to a call service system that processes large-scale call sessions in real time. Of course, there is a problem that causes leakage of personal information. Moreover, when personal information having a considerable data length is used as watermark information, an overload occurs in the call service system, and the watermark detection rate is remarkably lowered when a sound source file in which group call voices are recorded is changed by editing or the like. there is a problem

The technical problem to be solved by the present invention is to secure the security of the group call by tracing the outflow path of the sound source file even when the sound source file in which the voice of the group call is recorded is leaked, as well as to maintain the call quality It is to provide a communication terminal-based group call security device and method that prevents leakage of unique personal information of group call participants and overload of a call service system while guaranteeing a high level of watermark detection rate.

A group call security device based on a communication terminal according to an embodiment of the present invention performs security of a group call based on a communication terminal participating in a group call, and recalls participants participating in the group call using the communication terminal. a group call information receiving unit for receiving identification information for distinguishing participants from other participants in a group call from a predetermined system providing a group call security service for each group call session; a mark signal generator for generating a mark signal for an audio watermark using the participant identification information; and a watermarking unit processing group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transmitting the secure voice signal to a voice output unit of the communication terminal. can include

In one embodiment, the participant discrimination information received by the group call information receiving unit may be serial number information assigned to a corresponding participant within the maximum number of participants of the group call.

In one embodiment, the group call information receiver may further receive tag information for identifying the group call from the system and store it in a storage unit of the communication terminal.

In one embodiment, the mark signal generator may generate the mark signal by converting the participant identification information into bit data and applying Forward Error Correction (FEC).

In one embodiment, the watermarking unit may receive group call data processed through an application layer of the communication terminal.

In one embodiment, the communication terminal includes a signaling module in charge of signaling processing related to call connection, a transport module in charge of transmitting and receiving processing for group call data, and group call data. A packet data processing module for processing in packet units and a speech processing module for combining group call data packets and processing them in units of voice signals, wherein the watermarking unit is configured to perform the speech processing Group call data processed through the module can be delivered.

In one embodiment, the communication terminal includes a communication processor for processing group call data received through a Long Term Evolution (LTE) network, and the watermarking unit is processed through the communication processor. Group call data can be delivered.

In one embodiment, the communication terminal receives packet time information indicating a group call data packet processing time of the communication terminal from the system, and the watermarking unit is received by the communication terminal in real time The processed group call data may be divided into subframe units having a predetermined length in consideration of the packet time information, and the mark signal may be inserted into the subframe unit data in the frequency domain.

In one embodiment, the watermarking unit may divide the group call data into subframe units having a maximum length that can be processed within a processing time allowed by the watermarking unit according to the packet time information.

In one embodiment, the watermarking unit may generate the secure voice signal by masking the mark signal in the frequency domain and inserting it into the voice signal of the group call data.

In one embodiment, the device may further include a group call requesting unit for requesting opening of a group call by transmitting tag information for identifying the group call together with participant terminal information participating in the group call to the system. there is.

In one embodiment, the device transmits a sound source file recording voice of the group call and tag information of the group call to the system to request analysis of the sound source file, and an outflow path of the sound source file from the system. It may further include a sound source file analysis request unit for receiving information and displaying the information through a display unit of the communication terminal.

A group call security method based on a communication terminal according to an embodiment of the present invention is a method for performing group call security based on a communication terminal participating in a group call, wherein the communication terminal uses the communication terminal to group a group call. A group call information receiving step of receiving participant identification information for distinguishing a participant participating in a call from other participants in the group call from a predetermined system that provides a group call security service for each group call session; a mark signal generation step of generating, by the communication terminal, a mark signal for an audio watermark using the participant discrimination information; and the communication terminal processes group call data received by the communication terminal while the group call is being performed to generate a secure voice signal into which the mark signal is inserted, and transmits the secure voice signal to a voice output unit of the communication terminal. A watermarking step may be included.

In one embodiment, the participant identification information received in the group call information receiving step may be serial number information assigned to a corresponding participant within the maximum number of participants of the group call.

In an embodiment, the group call information receiving step may include the step of the communication terminal further receiving tag information for identifying the group call from the system and storing it in a storage means of the communication terminal.

In an embodiment, the generating of the mark signal may include generating the mark signal by converting the participant identification information into bit data and applying Forward Error Correction (FEC).

In one embodiment, the method further comprises receiving, by the communication terminal, packet time information representing a group call data packet processing time of the communication terminal from the system, wherein the watermarking step comprises: , The communication terminal divides the group call data received and processed by the communication terminal in real time into subframe units of a predetermined length in consideration of the packet time information, and the mark signal is applied to the subframe unit data in the frequency domain. It may include inserting.

In one embodiment, the watermarking step may be a step of dividing the group call data into subframe units having a maximum length that can be processed within a processing time allowed for the watermarking step according to the packet time information.

In one embodiment, the watermarking step may be a step of generating the secure voice signal by masking the mark signal in a frequency domain and inserting it into a voice signal of the group call data.

In one embodiment, the method may include a group call request step of requesting opening of a group call by the communication terminal transmitting tag information for identifying the group call together with participant terminal information participating in the group call to the system. may further include.

In one embodiment, the method, the communication terminal transmits a sound source file recording the voice of the group call and tag information of the group call to the system to request analysis of the sound source file, and the sound source from the system The method may further include a sound source file analysis request step of receiving information on an outflow path of a file and displaying the information through a display unit of the communication terminal.

Embodiments according to the present invention may be implemented as a computer program that executes the above-described operations or methods in a computer system.

According to the present invention, communication terminals performing a group call output group call voices watermarked with different information for distinguishing the corresponding participants, so that even when the sound source file in which the group call voice is recorded is leaked, It is possible to track the leakage path of the sound source file and secure the security of group calls.

Particularly, participant identification information, such as a serial number, which can minimize the amount of data by simply distinguishing participants only within a corresponding group call, is used as watermark information, and group call data received in real time by a communication terminal during a call process is used for the communication. By performing audio watermarking by dividing the group call data packet into the maximum length that can be processed within the processing time of the terminal, the basic call quality is maintained or improved, and even when the sound source file in which the group call voice is recorded is changed by editing, etc. level of watermark detection rate can be guaranteed.

In addition, by generating new participant identification information for watermarking for each group call session and using it as the watermark information for the group call, the unique information leakage problem that occurs when the fixed unique information of the participant is used as the watermark information is solved. It can be prevented.

In addition, the process of generating participant identification information for watermarking and the audio watermarking process using the participant identification information can be distributed and processed on the server side providing the group call security service and the communication terminal side participating in the group call, respectively. It is possible to save and prevent overloading of computing resources of a call service system that has to process a number of call sessions.

Furthermore, those skilled in the art to which the present invention belongs will be able to clearly understand from the following description that the embodiments according to the present invention can solve various technical problems not mentioned above.

1 is a diagram showing a group call environment to which the present invention is applied.
Figure 2 is a block diagram showing a group call security service providing system according to an embodiment of the present invention.
Figure 3 is a block diagram showing a group call security apparatus according to an embodiment of the present invention.
Figure 4 is a flow chart showing a group call opening process of the group call security method according to an embodiment of the present invention.
5A and 5B are diagrams illustrating an example of a user interface screen displayed on a communication terminal upon request for opening a group call.
6 is a diagram illustrating an example of a call processing framework applied to a call processing module of a mobile communication terminal.
7 is a block diagram showing a watermarking unit of a group call security device according to an embodiment of the present invention.
8 is a flowchart illustrating a sound source file analysis process of a group call security method according to an embodiment of the present invention.
9A to 9C are diagrams illustrating an example of a user interface screen displayed on a communication terminal when a sound source file analysis is requested.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to clarify solutions to the technical problems of the present invention. However, in the description of the present invention, if the description of the related known technology makes the gist of the present invention unclear, the description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of designers and manufacturers. Therefore, the definition should be made based on the contents throughout this specification.

1 shows a group call environment to which the present invention is applied.

As shown in FIG. 1, in a group call environment, users of a group call service use mobile communication terminals 10, 12, 14, and 16 that communicate with each other through a mobile communication network for remote meetings or collaboration. call can be made. In this case, the group call may be performed in a voice over LTE (VoLTE) scheme through a Long Term Evolution (LTE) network. In addition, the group call may be performed in a mobile voice over IP (mVoIP) method or a web real time communication (Web RTC) method through a public data network.

While a group call such as a conference call is in progress, a random participant among the participants belonging to the conference call group may capture audio of the group call voice output from the communication terminal 16 or use a separate voice recorder 20 It is recorded through, and the sound source file created accordingly can be leaked outside the company. In this way, when the sound source file recording the voice of the group call is leaked to the outside, the company may suffer damages such as leakage of trade secrets.

The group call security service providing system 100 and the communication terminal-based group call security device (not shown) according to the present invention are applied to such a group call environment to perform a group call. A plurality of communication terminals 10, 12, 14, 16) to output the group call voice watermarked with different participant identification information that distinguishes the corresponding participant, so that even if the sound source file recording the group call voice is leaked, the outflow path of the corresponding sound source file is tracked make it possible

2 shows a block diagram of a group call security service providing system 100 according to an embodiment of the present invention.

As shown in FIG. 2, the group call security service providing system 100 may include a call processing server 110, a security information management server 120, and an analysis server 140, and according to an embodiment, media A server 130, a subscriber database 150, and the like may be further included. In addition, the system 100 may further include a SIP server, an access gateway, an application server, an IMS server, and the like for providing basic call services. .

The call processing server 110 of the group call security service providing system 100 includes participant terminal information such as communication numbers of the participant terminals 12, 14, and 16 participating in the group call from the group call establisher terminal 10. In addition, a request to open a group call may be requested by receiving tag information identifying the corresponding group call. To this end, the call processing server 110 may include a group call information reception unit 112, a distinction information generation request unit 114, and a call connection request unit 116.

The group call information receiver 112 of the call processing server 110 may receive group call information including the participant terminal information and the tag information from the group call establisher terminal 10 . In addition, the tag information included in the group call information may be any one of information indicating a name of a group call such as a meeting name, a date and time of a call, and the names of participants, or a combination of two or more of these pieces of information. As will be explained again below, such group call information can be used as information for establishing a corresponding group call, as well as information for tracing the outflow path of a sound source file recording voices of a group call in the future.

The identification information generation request unit 114 of the call processing server 110 may forward the received group call information to the security information management server 120 to request generation of participant identification information.

The call connection requesting unit 116 of the call processing server 110 may request a call connection to the corresponding participant terminal using the participant terminal information. In particular, the call connection requesting unit 116 may transmit participant identification information of a corresponding participant to a corresponding terminal when a call is connected to each of the participant terminals 12, 14, and 16. For example, the call connection requesting unit 116 may include participant identification information in a call connection request message and transmit the call connection request message to the corresponding participant terminal.

In addition, the security information management server 120 of the group call security service providing system 100, for each participant participating in the group call, provides participant identification information for relatively distinguishing the corresponding participant from other participants of the group call for each group call session. and manage the participant identification information by associating with tag information of the group call and unique information of the corresponding participant. To this end, the security information management server 120 may include a identification information generator 122, a security information storage unit 124, and a unique information search unit 126.

When group call information including the participant terminal information and the tag information is transmitted from the call processing server 110, the identification information generation unit 122 of the security information management server 120 participates in the group call. The participant identification information may be generated for each participant. As will be described again below, the participant identification information is information for generating a mark signal to be watermarked in a group call voice output from a corresponding participant communication terminal.

The participant identification information may be simple serial number information assigned to a corresponding participant within the maximum number of participants of the group call. This minimizes the data of the mark signal to be watermarked to prevent the problem that the detection rate rapidly decreases in the watermark detection process as the mark signal data becomes longer, and at the same time, audio watermarking is performed using the fixed and unique personal information of the participant. This is to prevent the problem of personal information being exposed. For example, a group call establisher inputs group call tag information of '2016.04.02_product planning meeting' and the communication numbers of the participant terminals 12, 14, and 16 through a group call application installed in the corresponding terminal 10 to make a group call. When requesting opening of a call, the security information management server 120 may generate serial numbers from 1 to 4 corresponding to the number of participants in the corresponding group call and transmit them to the respective participant terminals.

The security information storage unit 124 of the security information management server 120 may store the participant identification information in association with the tag information and unique information of the corresponding participant. The unique information of the participant is information that absolutely identifies the participant, and may include personal information such as name, address, and communication terminal number of the participant. The security information storage unit 124 may receive and store unique information of a participant corresponding to the participant terminal information from a predetermined subscriber registration server (not shown) that stores and manages unique information of call service subscribers.

The unique information search unit 126 of the security information management server 120 transmits tag information for identifying a group call recorded in the sound source file from the analysis server 140 and participant identification information detected in the sound source file. In this case, the unique information of the participant corresponding to the detected participant identification information may be searched in the security information storage unit 124 using the transmitted tag information, and the search result may be transmitted to the analysis server 140. .

On the other hand, the analysis server 140 of the group call security service providing system 100 receives a request for analyzing a sound source file in which the voice of the group call is recorded from a predetermined terminal of a group call security service subscriber, and performs watermarking on the sound source file. When the detected participant identification information is detected, unique information of the participant corresponding to the detected participant identification information may be provided to the service subscriber terminal. To this end, the analysis server 140 may include a service subscriber identification unit 142, an analysis information reception unit 144, a discrimination information detection unit 146, and an outflow path information providing unit 148.

The service subscriber identification unit 142 of the analysis server 140 may receive identification information such as ID and password of the service subscriber from the service subscriber terminal, and confirm whether the service subscriber subscribes to the group call security service. In this case, the service subscriber terminal may be a mobile communication terminal (10, 12, 14, 16) of a group call establisher or participant, as well as a separate terminal capable of performing data communication through a network, such as a PC or laptop computer. there is. In addition, the service subscriber identification unit 142 compares the identification information received from the service subscriber terminal with the identification information of service subscribers stored in the subscriber database 150 to check whether the corresponding service subscriber subscribes to the service.

The analysis information receiver 144 of the analysis server 140 may receive, from the service subscriber terminal, analysis information including a sound source file in which a voice of a group call is recorded and tag information of a group call recorded in the sound source file.

The distinguishing information detection unit 146 of the analysis server 140 may detect participant distinguishing information watermarked in the sound source file, as will be described later.

The outflow path information providing unit 148 of the analysis server 140 transfers the detected participant identification information to the security information management server 120, and transmits the participant's unique information corresponding to the detected participant identification information to the security information management server 120. It can be received from the information management server 120 and provided to the service subscriber terminal as outflow path information of a sound source file.

On the other hand, the media server 130 of the group call security service providing system 100, after opening the group call, the participant terminals 10, 12, 14, 16 participating in the group call Mixing the voice data received from each Processing may be performed to generate group call data, and the generated group call data may be transmitted to the corresponding participant terminals 10, 12, 14, and 16, respectively.

3 shows a block diagram of a group call security device 200 according to an embodiment of the present invention.

As shown in Figure 3, the group call security device 200 is a device for performing group call security based on the communication terminal 300 participating in the group call, the group call information receiver 220, mark signal generation It includes a unit 230 and a watermarking unit 240, and may further include a group call request unit 210, a sound source file analysis request unit 250, and the like according to embodiments. The group call security device 200 may be implemented in the form of a software application and installed in the communication terminal 300, as well as implemented in the form of a microprocessor in which software and hardware are combined and installed in the communication terminal 300. may be In addition, the group call security device 200 may be installed in all communication terminals 10, 12, 14, and 16 participating in the group call, respectively.

Figure 4 is a flow chart showing a group call opening process of the group call security method according to an embodiment of the present invention. Referring to FIG. 4, the configuration and operation of the group call security apparatus 200 shown in FIG. 3 will be described in detail.

As shown in FIG. 4, first, the group call requesting unit 210 of the group call security device 200 installed in the group call establisher terminal 10 includes the participant terminal information of the participants participating in the group call and the group call It is possible to request opening of a group call by transmitting tag information identifying the group call security service providing system 100 (S410). In the case of a VoIP or VoLTE call, signaling processing uses a Session Initiation Protocol (SIP) protocol, and each participant participates in a group call through operation procedures such as registration, invite, and ACK. In addition, each participant may leave or newly join in the middle of a group call.

5A and 5B illustrate an example of a user interface screen displayed on a communication terminal upon request for opening a group call.

As shown in FIG. 5A, when a group call establishment request is made, the group call requesting unit 120 of the group call security device 200 displays the display means ( Through 306 of FIG. 3, an input window 500 for inputting tag information of a group call such as a meeting name and a meeting date and an input window 502 for selecting whether or not to use a security service are displayed, and the group call establisher terminal 10 It is possible to receive group call tag information and whether or not to use a security service from a group call establisher through a predetermined input means (302 in FIG. 3) of ). In addition, the group call requesting unit 120 may further receive participant terminal information including communication numbers of participants participating in the group call. The group call requesting unit 120 may request opening of a group call by transmitting the input group call tag information and participant terminal information to the system 100 .

On the other hand, as shown in FIG. 5B, the group call security device 200 stores the group call history in a database and stores it in the storage means (304 in FIG. 3) of the corresponding terminal, and displays the group call history list according to user selection. It can be displayed through (306 in FIG. 3). The group call history list may include group call tag information such as a conference name and date of the conference, and participant information such as a participant's name.

Referring back to FIG. 4, the call processing server 110 of the group call security service providing system 100 receives group call information including the participant terminal information and group call tag information from the group call establisher terminal 10. If so, the received group call information may be transferred to the secure information management server 120 to request generation of participant identification information (S420).

Next, the security information management server 120 of the group call security service providing system 100 provides participant identification information for each participant participating in the group call to relatively distinguish the corresponding participant from other participants in the group call session. The generated participant identification information may be associated with tag information of the group call and unique information of the corresponding participant, and stored and managed (S430). In this case, the generated participant identification information may be serial number information assigned to each participant within the maximum number of participants of the corresponding group call.

Next, the security information management server 120 of the group call security service providing system 100 transfers participant identification information (eg, serial number information for each participant) of the group call session to the group call security service providing system 100. ) to the call processing server 110 (S440), the call processing server 110 may request a call session connection to each of the participant terminals 12, 14, and 16 (S450). During this call connection process, the call processing server 100 and the participant terminals 12, 14, and 16 proceed with negotiation while exchanging various pieces of information for group call data transmission. In this case, the call processing server 110 transmits packet time information indicating the time at which the corresponding communication terminal should process group call data packets for smooth interworking with the participant terminals 12, 14, and 16, respectively. It can be transmitted to the participant terminals 12, 14, and 16 of. Such packet time information may be determined by considering a quality of service (QoS) policy and a communication channel condition.

In addition, the call processing server 110 may transmit a call connection request message such as an invite message to each participant terminal 12, 14, and 16, and the call connection request message includes the tag information of the group call and the corresponding participant terminal Participant identification information assigned to a user (group call participant) of may be included. Depending on the embodiment, of course, the participant identification information may be included in any one of several other messages transmitted in the protocol procedure of the corresponding group call and transmitted to the corresponding terminal.

Then, when the call connection acceptance is made at the participant terminals 12, 14, and 16 (S460), the group call establishment is completed and a multiway call is made between participants including the group call establisher (S470).

When a group call is established and a multi-party call is made, the media server 130 of the group call security service providing system 100 transmits voice messages received from the participant terminals 10, 12, 14, and 16 of the group call, respectively. Group call data may be generated by mixing data through voice codec, synchronization, etc., and the generated group call data may be transmitted to the corresponding participant terminals 10, 12, 14, and 16, respectively.

In this way, when group call data is received in the communication terminal 300 of the group call participant, the group call security device 200 installed in the corresponding communication terminal 300 performs group call data processing for security of the group call. do. To this end, the group call security device 200 may interwork with the call processing module 310 of the communication terminal 300 .

6 illustrates an example of a call processing framework applied to the call processing module 310 of the mobile communication terminal.

As shown in FIG. 6, in the case of a call processing module 310 of a mobile communication terminal based on Android OS, a Linux Kernel 610, a Media Server 620, a library binder ( Library Binder 630, application framework 640, and mVoIP/call application 650 layers.

The Linux kernel 610 is a layer that controls voice transmitted and received through hardware during a call. A communication processor 616 and an AP/CP IPC driver 614 controlling the communication processor 616 may be included.

The media server 620 is a layer in charge of audio data signal processing such as stream and mixing processing for media data, and provides a media play service for processing media chunk data during audio playback. Play Service) 622, and Audio Flinger 624, which is in charge of transmission or connection processing of audio data such as mixing or sampling of audio signals, Bluetooth connection, etc., and connects audio signals to external speakers It may include an audio HAL 626 that receives and controls an audio signal received from a driver or an audio signal received from a driver and an audio policy service/manager 628 that is in charge of policies and management for audio signal processing. can

The libmedia 632 of the library binder 630 layer serves to bind the media server 620 and the application framework 640 .

The application framework 640 is a layer that supports an API (Application Program Interface) so that the audio data processed in the raw layer can be used in the application layer, and a media player/recorder (Media Player/Recorder) that supports playback/recording functions of audio streams. Player/Recorder 642, Audio Track/Recorder 644 that supports playback/recording in audio chunk units, and Wave Shaping for audio data ) function, and an audio manager/service/system 648 that supports a function of managing audio-related functions of the application layer. there is.

The mVoIP/call application 650 is an application layer related to an actual call, and includes a signaling module 652 responsible for signaling processing related to call connection and the like, and a signaling module 652 responsible for transmitting and receiving processing for group call data. A transport module 654, a packet data processing module 656 that processes group call data in packet units, and speech processing that combines group call data packets and processes them in units of voice signals. A module (Speech Processing Module) 658 and the like may be included. In addition, a web RTC application module (not shown) may be further included to perform a voice call between web browsers using web real time communication (Web RTC) technology, which is one of the real-time communication standards, without the help of a plug-in.

Group call mobile applications applied to the communication terminal 300 include a Voice over Internet Protocol (VoIP) application using a public network, a Web Real Time Communication (RTC) application, and a Long Term Evolution (LTE) network There are VoLTE (Voice over LTE) applications using .

When a VoIP application or a web RTC application is applied for a group call, group call data may be received and processed through an application layer of a corresponding communication terminal. For example, the signaling module 652 of the communication terminal 300 performs signaling with the call processing server 110 and the like using the SIP protocol, and after the call is connected, the transmission module 654 of the communication terminal 300 processes packet data. Group call data is received via module 656 and speech processing module 658 . The group call data received by the communication terminal 300 in this way is again transmitted to the audio driver 612 via the audio track 644, libmedia 632, audio plunger 624, and audio HAL 626, , It is delivered to the group call participants as actual sign language through the audio output means 308, such as an internal/external speaker controlled by the audio driver 612. In this case, the group call security apparatus 200 may acquire group call data at the application layer for group call security, convert it into a voice signal, and then perform audio watermarking on the corresponding voice signal.

Meanwhile, when a VoLTE application is applied for a group call, unlike the case of a VoIP application, transmission/reception of group call data packets is performed by the communication processor 616 rather than by the application layer. In this case, the group call security device 200 may obtain group call data by connecting the application layer and the AP/CP IPC driver 614 through a RIL (Radio Interface Layer) and accessing an audio chunk data packet. there will be The group call security device 200 may convert the obtained group call data packet into a voice signal and then perform audio watermarking on the corresponding voice signal.

Referring back to FIG. 3 , the group call security device 200 may perform group call data processing for group call security in conjunction with the call processing module 310 of the above-described communication terminal 300 .

First, the group call information receiver 220 of the group call security device 200 provides participant identification information for distinguishing a participant participating in a group call using the corresponding communication terminal 300 from other participants in the group call. It can be received for each group call session from the call security service providing system 100 . In this case, the group call information receiver 220 may further receive packet time information indicating a group call data packet processing time of the corresponding communication terminal 300 from the system 100 . At this time, the group call information receiver 220 may receive packet time information and participant identification information through the call processing module 310 of the communication terminal 300 . That is, the signaling module 652 constituting the call processing module 310 of the communication terminal 300 performs an information exchange function related to group call establishment, so that the packet is transmitted from the call processing server 110 of the system 100. Upon receiving the call connection request message including the time information and the participant identification information, the group call information receiving unit 220 may extract the participant identification information from the call connection request message and transmit it to the mark signal generator 230. In this case, the participant identification information may be serial number information assigned to a corresponding participant within the maximum number of participants of the group call. Meanwhile, the group call information receiving unit 220 may transfer the packet time information to the watermarking unit 240 .

In addition, the group call information reception unit 220 further receives tag information for identifying the group call and participant information of the group call from the system 100 and stores them in the storage unit 304 of the communication terminal 300. can As will be described again below, the tag information of the group call and the participant information of the corresponding group call can be used as analysis information in a sound source file analysis request process in the future.

Next, the mark signal generation unit 230 of the group call security apparatus 200 may generate a mark signal for audio watermarking using the participant identification information. In this case, the mark signal generation unit 230 may convert the participant discrimination information into bit data and apply Forward Error Correction (FEC) to generate a mark signal in the form of an audio signal for later detection. Examples of FEC applicable to audio watermarking include BCH Code, Reed-Solomon (RS) Code, and Turbo Code.

Next, the watermarking unit 240 of the group call security device 200 processes the group call data received by the communication terminal 300 while the group call is being performed to generate a secure voice signal in which the mark signal is inserted. And, the security voice signal can be delivered to the voice output unit 308 such as a speaker of the communication terminal 300.

More specifically, when the communication terminal 300 receives group call data through a VoIP application or a web RTC application, the watermarking unit 240 performs group processing through the application layer of the communication terminal 300. You can receive call data. For example, the watermarking unit 240 may receive group call data through the speech processing module 658 of the communication terminal 300 . That is, among the detailed configuration modules included in the call processing module 310 of the communication terminal 300, the signaling module 652 performs signaling to perform call connection for a group call, and the transmission module 654 performs call After connection, group call data can be received through the public network. Then, the packet data processing module 656 processes the group call data in units of packets, and the speech processing module 658 combines and decodes the group call data packets, processes them in units of voice signals, and transmits the data to the watermarking unit 240. can be conveyed

Meanwhile, when the communication terminal 300 receives group call data through the VoLTE application, the watermarking unit 240 may receive the group call data from the communication processor 616 of the communication terminal 300 . That is, the communication processor 616 constituting the call processing module 310 of the communication terminal 300 receives group call data through the LTE network, and transmits the received group call data to the AP/CP IPC driver 614 and the communication processor 616. It can be transmitted to the watermarking unit 240 through a RIL (Radio Interface Layer) connected to an application.

Also, the watermarking unit 240 may process the group call data to generate a secure voice signal in which the mark signal is inserted. In this case, the watermarking unit 240 may generate a secure voice signal by applying various audio watermarking technologies. Audio watermarking technology includes a method of inserting (mixing) a mark signal into a specific audio data frame position in an inaudible region in an audio signal and a method of inserting an audio mark signal by changing a host audio. In order to prevent leakage of sound source files that record group call voices, even if watermarked sound source files are modified, watermarking information must be detectable at a certain level or higher. It is preferable to apply the method of changing and inserting the actual host sound source rather than applying the method. Various algorithms such as Low Bit Coding, Phase Coding, Spread Spectrum Watermarking, Echo Embedding, and Patchwork have been introduced as a method of changing the host sound source.

In these audio watermarking technologies, when performing audio watermark embedding processing in the frequency domain through Fourier transform, etc., as the length of a data frame to be a Fourier transform increases, the resolution of the frequency domain increases and the mark Since the signal insertion space is widened, the watermark detection rate can be increased. However, it should be noted that, in a real-time call service environment, as the length of a data frame subject to Fourier transform increases, processing time increases and call sound delay occurs, resulting in deterioration in call quality.

Therefore, unlike existing technologies in which a watermark is inserted by simply dividing static audio content into fixed lengths, the present invention transmits host audio of group call data received in real time during a call process to the communication terminal 300. Considering the required processing time for group call data packets, segmentation is performed, and audio watermarking is performed by segmenting into the maximum length that can be processed within the allowable processing time, thereby preventing call sound delay and improving QoS (Quality of Service). While maintaining the audio watermark detection rate, it is possible to maximize the audio watermark detection rate.

That is, when the communication terminal 300 receives packet time information indicating a group call data packet processing time of the communication terminal 300 from the system 100, the watermarking unit 240 performs the group call data packet processing time. Corresponding packet time information may be received through the call information receiving unit 220 . Further, the watermarking unit 240 divides the group call data received and processed by the communication terminal 300 in real time into subframe units of a predetermined length in consideration of the packet time information, and converts the mark signal in the frequency domain. It can be inserted into the data in units of the subframe. In this case, the watermarking unit 240 may divide the host audio of the group call data into subframe units having a maximum length that can be processed within a processing time permitted by the watermarking unit according to the packet time information.

7 shows a block diagram of a watermarking unit 240 of the group call security apparatus according to an embodiment of the present invention.

As shown in FIG. 7, the watermarking unit 240 of the group call security apparatus 200 includes a frame division unit 241, an FFT unit 242, a watermark insertion unit 243, and a frame reconstruction unit 244. ), and an IFFT unit 245.

The frame dividing unit 241 may divide host audio of group communication data received and processed by the communication terminal 300 in real time into subframe units having a predetermined length. In this case, the frame division unit 241 calculates the maximum number of packets that the watermarking unit 240 can process within a predetermined processing time according to the packet time information, and considers the number of packets to determine the subframe length. Host audio can be split to maximize.

The FFT unit 242 transforms the host audio divided into subframes into a frequency domain through fast Fourier transform (FFT). The watermark inserter 243 inserts a mark signal into the signal converted into the frequency domain. In this case, the watermark embedding unit 243 stores the received frequency domain signal in a buffer and inserts audio mark information at intervals of a predetermined length. As an algorithm for embedding an audio mark signal, phase coding, spread spectrum watermarking, echo embedding, and the like may be applied. Meanwhile, the watermark insertion unit 243 may transform the audio mark signal into inaudible so that the original sound is not damaged even when the audio mark signal is inserted into the voice signal of a group call. For example, when the Spread Spectrum Watermarking algorithm is applied, the watermark insertion unit 243 performs masking processing according to a psychoacoustic model in consideration of the frequency and volume of the host sound source subjected to FFT, thereby producing an audio mark signal can be made inaudible. When the watermark embedding unit 243 inserts an audio mark signal in the frequency domain, the frame reconstruction unit 244 may reconstruct the corresponding signal to an original frame length. At this time, a signal for synchronization may be inserted. The IFFT unit 245 converts the reconstructed signal data into a time domain signal through an inverse fast Fourier transform (IFFT) to finally generate a watermarked secure voice signal.

The secure voice signal generated in this way is returned to the speech processing module 658 and transmitted to the audio output means 308 of the communication terminal 300 through the audio track 644 and the audio HAL 626, and is then delivered to the communication terminal user. can be played as an audible call tone.

Referring back to FIG. 3 , the sound source file analysis request unit 250 of the group call security device 200 transmits the corresponding sound source file and the tag information of the group call when leakage of the sound source file recording the voice of the group call occurs. It transmits to the call security service providing system 100 to request analysis of the sound source file, receives the outflow path information of the sound source file from the system 100, and displays the sound source file through the display means 306 of the communication terminal 300. can be displayed

8 is a flowchart illustrating a process of analyzing a sound source file of a group call security method according to an embodiment of the present invention. Referring to FIG. 8, the configuration and operation of the group call security apparatus 200 shown in FIG. 3 will be described in detail.

As shown in FIG. 8, group call security service subscribers, for example, group call participants, including group call establishers, use their own communication terminals to make a group call when a sound source file recording the group call voice is leaked. Analysis of the leaked sound source file may be requested from the security service providing system 100, and leak path information of the corresponding sound source file may be provided. In FIG. 8, a case in which the communication terminal of the group call establisher corresponds to the service subscriber terminal 10 will be described as an example.

First of all, the sound source file analysis request unit 250 of the group call security device 200 installed in the service subscriber terminal 10 converts the sound source file recording the group call voice and tag information of the group call to the group call security service providing system. It can be transmitted to (100) to request analysis of the sound source file (S810 to S840). In this case, the sound source file analysis request unit 250 of the group call security device 200 accesses the group call security service providing system 100 before transmitting the sound source file and proceeds with a log-in procedure to check whether the service subscriber is applicable. can

9A to 9C illustrate an example of a user interface screen displayed on a communication terminal when a sound source file analysis is requested.

As shown in FIG. 9A, the sound source file analysis request unit 250 of the group call security device 200 displays a login screen through the display means 306 of the corresponding service subscriber terminal 10, and receives an ID from the user. And identification information such as a password may be received and the identification information may be transmitted to the group call security service providing system 100 through the data communication module (320 in FIG. 3) of the service subscriber terminal 10 (S810).

The analysis server 140 of the group call security service providing system 100 may use the identification information received from the service subscriber terminal 10 to check whether the corresponding user subscribes to the group call security service (S820). In this case, the analysis server 140 compares the identification information received from the service subscriber terminal with the identification information of the service subscribers stored in the predetermined subscriber database 150 to determine whether the corresponding user subscribes to the service. When the service subscription is confirmed, the analysis server 140 may request analysis information from the service subscriber terminal 10 (S830).

Then, as shown in FIG. 9B, the sound source file analysis request unit 250 of the group call security device 200 displays an analysis information input screen through the display means 306 of the service subscriber terminal 10 and , Analysis information including the analysis target sound source file stored in the storage means (304 in FIG. 3) of the service subscriber terminal 10 and the tag information of the group call recorded in the corresponding sound source file is input, and the analysis information is transmitted to the service subscriber. It can be transmitted to the group call security service providing system 100 through the data communication module (320 in FIG. 3) of the terminal 10 (S840). In this case, the sound source file analysis request unit 250 of the group call security device 200 includes group call tag information such as the meeting name and date of the meeting and group call participant information such as the participant's name on the analysis information input screen. By displaying the history list, it is possible for a user to easily find group call tag information related to a sound source file to be analyzed. For example, a service subscriber selects a sound source file to be analyzed from among files stored in the corresponding service subscriber terminal 10 and clicks 'Product Planning Meeting 16_4_2' among the group call details displayed in the group call history list to analyze the corresponding sound source file. can request

Next, the analysis server 140 of the group call security service providing system 100 may detect participant identification information watermarked in the sound source file received from the service subscriber terminal 10 (S850). In this case, the analysis server 140 may detect participant discrimination information from the sound source file by applying various detection techniques for detecting audio watermarked information. A technology for detecting audio watermarking information is determined according to an audio watermarking algorithm and can be largely divided into a blind method and a non-blind method. Since storing the group call content in the group call security service providing system 100 itself can impair the security of the group call, the analysis server 140 applies a blind detection method to distinguish participants from the corresponding sound source file. information can be detected.

Next, the analysis server 140 of the group call security service providing system 100 transfers the group call tag information received from the service subscriber terminal 10 and the detected participant identification information to the group call security service providing system 100. It can be delivered to the security information management server 120 of (S860).

The security information management server 120 of the group call security service providing system 100 searches for participant's unique information corresponding to the detected participant identification information using the group call tag information transmitted from the analysis server 140. (S870), and the corresponding search result may be transmitted to the analysis server 140 (S880). In this case, the security information management server 120 compares the group call tag information and participant identification information transmitted from the analysis server 140 with the tag information and participant identification information stored in the group call opening process to match the participant identification information. By discovering, it is possible to retrieve participant-specific information stored in association with the corresponding participant identification information. In this case, the participant's unique information may include personal information such as the participant's name, address, and communication terminal number.

Next, the analysis server 140 of the group call security service providing system 100 receives the participant's unique information corresponding to the detected participant discrimination information from the security information management server 120, and the outflow path of the sound source file. As information, it can be provided to the service subscriber terminal 10 (S890).

As shown in FIG. 9C, the sound source file analysis request unit 250 of the group call security device 200 converts the participant-specific information received from the group call security service providing system 100 to the outflow path information of the corresponding sound source file. As , it can be displayed through the display means 306 of the service subscriber terminal 10 .

Meanwhile, embodiments of the present invention can be implemented by recording a computer-readable computer program on a computer-readable recording medium. When the embodiments of the present invention are implemented using a computer program, the constituent means of the present invention are program code segments that execute necessary tasks. These computer programs or code segments may be stored in a computer-readable recording medium or combined with a carrier wave and transmitted in the form of a data signal through a transmission medium or a communication network. Computer-readable recording media include all types of media on which data that can be read by a computer system is recorded. For example, computer-readable recording media may include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like. Also, program codes can be stored or executed in a distributed manner by distributing and arranging these recording media in computer systems connected through various networks.

As described above, according to the present invention, the communication terminals performing the group call output the group call voice watermarked with different information for distinguishing the corresponding participants, so that the corresponding group call voice is recorded as a sound source file. Even if this is leaked, the source file's leak path can be traced and the security of the group call can be secured. Particularly, participant identification information, such as a serial number, which can minimize the amount of data by simply distinguishing participants only within a corresponding group call, is used as watermark information, and group call data received in real time by a communication terminal during a call process is used for the communication. By performing audio watermarking by dividing the group call data packet into the maximum length that can be processed within the processing time of the terminal, the basic call quality is maintained or improved, and even when the sound source file in which the group call voice is recorded is changed by editing, etc. level of watermark detection rate can be guaranteed. In addition, by generating new participant identification information for watermarking for each group call session and using it as the watermark information for the group call, the unique information leakage problem that occurs when the fixed unique information of the participant is used as the watermark information is solved. It can be prevented. In addition, the process of generating participant identification information for watermarking and the audio watermarking process using the participant identification information can be distributed and processed on the server side providing the group call security service and the communication terminal side participating in the group call, respectively. It is possible to save and prevent overloading of computing resources of a call service system that has to process a number of call sessions. Furthermore, the embodiments according to the present invention can solve various technical problems other than those mentioned in this specification in the related art as well as in the related art.

So far, the present invention has been described with reference to specific examples. However, those skilled in the art will clearly understand that various modified embodiments can be implemented within the technical scope of the present invention. Therefore, the embodiments disclosed above should be considered from a descriptive point of view rather than a limiting point of view. That is, the scope of the true technical spirit of the present invention is shown in the appended claims, and all differences within the scope of equivalents thereto should be construed as being included in the present invention.

100: Group call security service providing system 110: Call processing server
120: security information management server 130: media server
140: analysis server 150: subscriber database
200: group call security device 210: group call request unit
220: group call information receiver 230: mark signal generator
240: watermarking unit 250: sound source file analysis request unit
300: communication terminal

Claims (22)

A group call security device that performs security of a group call based on a communication terminal participating in the group call,
a group call information receiving unit configured to receive participant identification information for distinguishing a participant participating in a group call using the communication terminal from other participants in the group call, for each group call session, from a predetermined system providing a group call security service;
a mark signal generator for generating a mark signal for an audio watermark using the participant identification information; and
A watermarking unit processing group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transmitting the secure voice signal to a voice output means of the communication terminal do,
The mark signal generating unit converts the participant identification information into bit data and applies FEC (Forward Error Correction) to generate the mark signal. According to claim 1,
The participant identification information received by the group call information receiver is serial number information assigned to a corresponding participant within the maximum number of participants in the group call. According to claim 1,
The group call information receiving unit further receives tag information for identifying the group call from the system and stores it in a storage means of the communication terminal. delete According to claim 1,
The watermarking unit is a communication terminal-based group call security device, characterized in that for receiving the group call data processed through the application layer of the communication terminal. According to claim 5,
The communication terminal includes a signaling module in charge of signaling processing related to call connection, a transport module in charge of transmitting and receiving processing for group call data, and a packet processing group call data in units of packets. A data processing module (Packet Data Processing Module) and a speech processing module (Speech Processing Module) that combine group call data packets and process them in units of voice signals,
The watermarking unit is a communication terminal-based group call security device, characterized in that for receiving the group call data processed through the speech processing module. According to claim 1,
The communication terminal includes a communication processor that processes group call data received through a Long Term Evolution (LTE) network,
The watermarking unit is a communication terminal-based group call security device, characterized in that for receiving the group call data processed through the communication processor. A group call security device that performs security of a group call based on a communication terminal participating in the group call,
a group call information receiving unit configured to receive participant identification information for distinguishing a participant participating in a group call using the communication terminal from other participants in the group call, for each group call session, from a predetermined system providing a group call security service;
a mark signal generator for generating a mark signal for an audio watermark using the participant identification information; and
A watermarking unit processing group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transmitting the secure voice signal to a voice output means of the communication terminal do,
The communication terminal receives packet time information indicating a group call data packet processing time of the communication terminal from the system,
The watermarking unit divides the group call data received and processed by the communication terminal in real time into subframe units of a predetermined length in consideration of the packet time information, and divides the mark signal into the subframe unit data in the frequency domain. Communication terminal-based group call security device characterized in that the insertion. According to claim 8,
The watermarking unit divides the group call data into subframe units having a maximum length that can be processed within a processing time allowed by the watermarking unit according to the packet time information. According to claim 1,
The watermarking unit masks the mark signal in the frequency domain and inserts it into the voice signal of the group call data to generate the secure voice signal. According to claim 1,
The apparatus further comprises a group call requesting unit for requesting opening of a group call by transmitting tag information for identifying the group call together with information on participant terminals participating in the group call to the system. group call security device. A group call security device that performs security of a group call based on a communication terminal participating in the group call,
a group call information receiving unit configured to receive participant identification information for distinguishing a participant participating in a group call using the communication terminal from other participants in the group call, for each group call session, from a predetermined system providing a group call security service;
a mark signal generator for generating a mark signal for an audio watermark using the participant identification information; and
A watermarking unit processing group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transmitting the secure voice signal to a voice output means of the communication terminal do,
The device transmits a sound source file recording voice of the group call and tag information of the group call to the system to request analysis of the sound source file, and receives outflow path information of the sound source file from the system to perform the communication A communication terminal-based group call security device further comprising a sound source file analysis request unit displayed through a display means of the terminal. A group call security method for performing security of a group call based on a communication terminal participating in the group call,
A group call in which the communication terminal receives participant identification information for distinguishing a participant participating in a group call using the communication terminal from other participants in the group call from a predetermined system providing a group call security service for each group call session. information receiving step;
a mark signal generation step of generating, by the communication terminal, a mark signal for an audio watermark using the participant discrimination information; and
The communication terminal processes group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transfers the secure voice signal to a voice output unit of the communication terminal. Including a watermarking step to
The step of generating the mark signal is a step of generating the mark signal by converting the participant identification information into bit data and applying FEC (Forward Error Correction). According to claim 13,
The participant identification information received in the group call information receiving step is a communication terminal-based group call security method, characterized in that the serial number information assigned to the corresponding participant within the maximum number of participants in the group call. According to claim 13,
The group call information receiving step comprises the step of the communication terminal further receiving tag information for identifying the group call from the system and storing it in a storage means of the communication terminal. security method. delete A group call security method for performing security of a group call based on a communication terminal participating in the group call,
A group call in which the communication terminal receives participant identification information for distinguishing a participant participating in a group call using the communication terminal from other participants in the group call from a predetermined system providing a group call security service for each group call session. information receiving step;
a mark signal generation step of generating, by the communication terminal, a mark signal for an audio watermark using the participant discrimination information; and
The communication terminal processes group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transfers the secure voice signal to a voice output unit of the communication terminal. Including a watermarking step to
The method further comprises receiving, by the communication terminal, packet time information indicating a group call data packet processing time of the communication terminal from the system;
In the watermarking step, the communication terminal divides the group call data received and processed in real time by the communication terminal into subframe units having a predetermined length in consideration of the packet time information, and converting the mark signal into the subframe unit in the frequency domain. A communication terminal-based group call security method comprising the step of inserting data in units of frames. According to claim 17,
The watermarking step is a step of dividing the group call data into subframe units having a maximum length that can be processed within a processing time allowed for the watermarking step according to the packet time information. security method. According to claim 13,
The watermarking step is a step of masking the mark signal in the frequency domain and inserting it into the voice signal of the group call data to generate the secure voice signal. According to claim 13,
The method further comprises a group call request step of requesting opening of a group call by the communication terminal transmitting tag information for identifying the group call together with information on participant terminals participating in the group call to the system. A communication terminal-based group call security method. A group call security method for performing security of a group call based on a communication terminal participating in the group call,
A group call in which the communication terminal receives participant identification information for distinguishing a participant participating in a group call using the communication terminal from other participants in the group call from a predetermined system providing a group call security service for each group call session. information receiving step;
a mark signal generation step of generating, by the communication terminal, a mark signal for an audio watermark using the participant discrimination information; and
The communication terminal processes group call data received by the communication terminal during the group call to generate a secure voice signal into which the mark signal is inserted, and transfers the secure voice signal to a voice output unit of the communication terminal. Including a watermarking step to
In the method, the communication terminal transmits a sound source file recording voice of the group call and tag information of the group call to the system, requests analysis of the sound source file, and extracts outflow path information of the sound source file from the system. The communication terminal-based group call security method further comprising the step of requesting an analysis of a sound source file received and displayed through a display means of the communication terminal. A computer program recorded on a recording medium as a computer program for executing the method according to any one of claims 13 to 15 and 17 to 21 through a computer system.

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