KR101173628B1 - Ad-hoc wireless instant messenger system and service security method thereof - Google Patents

Abstract

Ad-hoc wireless instant messenger system and security method are provided. An ad hoc instant messenger system according to an aspect of the present invention provides an instant messaging service to a temporary friend list composed of a mobile terminal in a wireless communication state with the mobile terminal, and upon completion of execution of a server module, is included in the temporary friend list. Transfer the status of the mobile instant messenger server to the mobile terminal selected as the next server among the mobile terminals, and provide NPSK (New Pre-Shared Key) generated by the next server to all mobile terminals included in the temporary friend list. Transmit instant messenger data between a mobile instant messenger server and another terminal included in the temporary friend list, and when the mobile instant messenger is transferred to the next server, perform mutual authentication using the NPSK provided from the mobile instant messenger server. To connect to the next server by It includes a terminal.

Ad Hoc, Messenger, PSK, Security, Authentication

Description

Ad-hoc wireless instant messenger system and service security method

The present invention relates to an ad hoc wireless instant messenger system and a service security method. More specifically, in an ad hoc wireless instant messenger system configured by operating a mobile terminal having an instant messenger server program as a mobile router, even when the mobile router is changed to another mobile terminal, the mobile terminal may be connected to the instant messenger system through mutual authentication. The present invention relates to an ad hoc wireless instant messenger system and a service security method for maintaining the security of the wireless instant messenger system in a manner of allowing access only to an authorized mobile terminal.

Recently, many dual mode mobile terminals supporting both 2G (Generation) / 3G (Generation) mobile communication and Wireless Local Area Network (WLAN) based on Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard It is used. Mobile terminals using wireless LANs are increasing in use because wireless internet access is possible at a low cost from several megabytes (IEEE 802.11g) to hundreds of megabytes (IEEE 802.11n). The dual mode mobile terminal has both a wireless LAN capable of short-range communication and a 2G / 3G mobile communication interface capable of long-distance communication. In particular, some models may have sufficient computational power of a built-in central processing unit to perform packet intermediation. It is so good that it can be used as a mobile router. For reference, a mobile router refers to an internet router that supports multi-party internet communication between mobile terminals using a plurality of wireless communication interfaces.

1 is a block diagram of a wireless instant messenger system using a mobile router.

As shown in FIG. 1, it can be seen that the mobile terminal is connected to an instant messenger server to use an instant messenger service by being connected to a mobile router through a wireless local area network (WLAN).

However, the communication between the mobile router and the mobile terminal may be interrupted intermittently due to the movement of the mobile router and the mobile terminal, which causes a problem in that service stability is problematic.

In addition, the mobile router may be connected only in a limited communication area, and the mobile router itself may move, and thus, a friend list type conversation target operating method used in the existing instant messenger system may not be effective.

In addition, when the mobile routers cannot support the mobile terminals due to the movement of the mobile router or the mobile router does not operate normally, the instant messenger service between all mobile hosts connected to the mobile router is interrupted.

Moreover, when there are a plurality of mobile routers in an area accessible from the WLAN, a problem of wasting unnecessary resources occurs. Accordingly, when there are a plurality of mobile router candidate devices, one of the mobile router candidate devices is selected to perform the mobile router function, and when the mobile router function can no longer perform the function of the mobile router, the neighboring mobile router candidate devices are selected. With the technology of selecting a device as a new mobile router, there is a need to provide a stable instant messenger service.

In addition, due to the characteristics of the wireless signal, the security of the network using a wireless LAN is important, so if the mobile router is changed, the new mobile router may have an authentication method and other security technology for which mobile terminal to allow access. It is required.

The technical problem to be solved by the present invention is that when the mobile terminal that performed the function of the mobile instant messenger server can no longer perform the function of the server, the next instant messenger of one of the mobile terminals included in the friend list The next instant messenger server provides an ad hoc wireless instant messenger system and a service security method for allowing access to only mobile terminals connected to a previous instant messenger server. It is.

Ad-hoc instant messenger system according to an aspect of the present invention for achieving the above technical problem provides an instant messaging service to a temporary friend list consisting of a mobile terminal in a state capable of wireless communication with itself, server module At the end of the execution, transfer the status of the mobile instant messenger server to the mobile terminal selected as the next server among the mobile terminals included in the temporary friend list, wherein the NPSK (New Pre-Shared Key) generated by the next server is recalled. The mobile instant messenger server is provided to all mobile terminals included in the temporary friend list and other instant messenger data are transmitted and received between the mobile terminal and the mobile instant messenger when the mobile instant messenger is transferred to the next server. Perform mutual authentication using the NPSK provided from the server By including the mobile terminal to be connected to the next server. The mutual authentication may be performed based on the WPA-Personal procedure of Institute of Electrical and Electronics Engineers (IEEE) 802.11i. In addition, the instant messenger data may be encrypted and transmitted based on at least one of a Counter mode with Cipher block chaining message authentication code protocol (CCMP) protocol of IEEE 802.11i and a Temporal Key Integrity Protocol (TKIP) protocol of IEEE 802.11. .

The mobile instant messenger server transmits a selection notification signal to the next server, and when the server ready to run server including the NPSK is received from the next server, sends the NPSK to all mobile terminals included in the temporary friend list. After transmitting the temporary friend list data to the next server, execution of the server module may be terminated. In this case, when the selection notification signal is received, the next server executes the server module to generate the NPSK, and then transmits the server execution ready signal including the NPSK to the mobile instant messenger server. When the temporary friend list data is received, the access request signal may be transmitted to all mobile terminals included in the temporary friend list data. The access request signal may include a pre-shared key (PSK) request message. That is, the mobile terminal receiving the access request signal can know that the corresponding access request must undergo mutual authentication using the PSK.

According to another aspect of the present invention, there is provided a security method of an ad-hoc instant messenger system, wherein one of the mobile terminals included in the temporary friend list is selected as a next server, and the next Transmitting a selection notification signal to a server; Receiving a new pre-shared key (NPSK) generated when the selection notification signal of the next server is received from the next server and providing the same to all mobile terminals included in the temporary friend list; And performing, by the mobile terminal, mutual authentication using the next server and the NPSK. The mobile instant messenger server may perform the security method of the ad-hoc instant messenger system according to the present aspect.

When receiving the server performance request signal from the mobile instant messenger server according to another aspect of the present invention for achieving the above technical problem, it is determined whether to support the server performance, if it is determined to support the server performance support signal Transmitting a selection notification signal from a mobile instant messenger server, activating an instant messenger server function, and generating and providing a new pre-shared key (NPSK) to the mobile instant messenger server; When the temporary friend list data is received, transmitting a connection request signal including a PSK request message to all mobile terminals included in the temporary friend list data; And performing mutual authentication using the NPSK with the mobile terminal included in the temporary friend list data. The security method of the ad-hoc instant messenger system according to the present aspect may be performed by a mobile terminal operating as a next server while using an instant messenger service.

According to the present invention as described above, even if the mobile terminal that performed the function of the mobile instant messenger server is no longer able to perform the function of the server, the next instant messenger of the mobile terminal of one of the mobile terminals included in the friend list By selecting the server to perform the function of the server has the effect that can provide a seamless ad hoc wireless instant messenger service.

In addition, even if the mobile instant messenger server is changed to the next server, the next server can be accessed only by the mobile terminal connected to the previous instant messenger server, so that an intruder can easily access the server for the replacement of the instant messenger server. It is effective to overcome security weaknesses.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, the present invention will be described with reference to a block diagram or a flowchart illustrating a method for managing an ad hoc wireless instant messenger system and a service management method according to embodiments of the present invention. At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps are performed on the computer or other programmable data processing equipment to create a computer-implemented process to generate a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

Hereinafter, the configuration and operation of the ad hoc instant messenger system according to an embodiment of the present invention will be described with reference to FIG. 2. 2 is a diagram showing the configuration before and after the mobile instant messenger server change of the ad hoc instant messenger system according to the present embodiment. As shown in FIG. 2, the ad hoc instant messenger system according to the present embodiment may include a mobile instant messenger server and one or more mobile terminals. In addition, it may further include an existing general-purpose instant messenger server 300 connected through the network 400. That is, the mobile instant messenger server 100 may operate as a proxy server of the universal instant messenger server 300.

As shown in Fig. 2, the ad hoc instant messenger system according to the present invention includes at least one mobile terminal supporting the same wireless communication interface. Among the mobile terminals, a terminal providing an instant messenger service to another mobile terminal by activating a function of an instant messenger server is referred to as a mobile instant messenger server, and a terminal receiving a messenger service from the mobile instant messenger server is referred to as a mobile terminal. Shall be. FIG. 2 illustrates that the mobile instant messenger server 100 may transfer the status of the mobile instant messenger server by selecting the mobile terminal 200 which is a conventional instant messenger service as the next mobile instant messenger. At this time, the mobile instant messenger server 100 deactivates the function of the server, and the next server 200 activates the function of the server. To this end, it will be understood that each mobile terminal should include a server module. In addition, it will be readily understood that the mobile terminal not including the server module cannot be selected as the next server 200.

In this case, the term 'module' of the 'server module' refers to software or a hardware component such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and the module performs certain roles. However, a module is not limited to software or hardware. The module may be configured to be in an addressable storage medium and may be configured to play one or more processors. Thus, as an example, a module may include components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, subroutines, and the like. , Segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and modules may be combined into a smaller number of components and modules or further separated into additional components and modules. In addition, the components and modules may be implemented to play one or more CPUs in a device or secure multimedia card.

Hereinafter, the configuration and operation of the ad hoc instant messenger system including the one mobile instant messenger server 100 and the mobile terminals 200, 202, and 204 before changing the server will be described first. The operation will be described.

(1) Configuration and operation of instant messenger service of ad hoc instant messenger system

The mobile instant messenger server 100 is a device capable of wireless communication with the mobile terminals 200, 202, and 204, and may be a device capable of installing an ad hoc instant messenger server module. The mobile instant messenger server 100 includes a mobile terminal 200, 202, and 204, a wireless local area network (WLAN), Bluetooth, Bluetooth, Radio-frequency Identification (RFID), Infrared Data Association (IrDA), and Zigbee. It can communicate using at least one of (ZigBee).

The mobile instant messenger server 100 provides a temporary friend list including the mobile terminals 200, 202, and 204 in a state capable of wireless communication with the mobile terminal 200, 202, and 204 included in the friend list. do.

The mobile instant messenger server 100 is located within a communication radius of the wireless communication interface supported by the mobile instant messenger server 100, and if there are mobile terminals 200, 202, and 204 activated with the wireless communication interface, It may include a server module for providing an instant messenger service including the 200, 202, 204 as a temporary friend list.

Unlike the friend list of the conventional instant messenger service, the temporary friend list includes only the mobile terminals 200, 202, and 204 currently connected to the mobile instant messenger server 100 as a friend list. Therefore, the mobile instant messenger server 100 periodically determines whether to connect with the mobile terminals 200, 202, and 204 included in the temporary friend list, so that the mobile terminal not currently connected may be removed from the friend list.

The mobile instant messenger server 100 can provide an instant messenger service quickly without complicated messenger subscription and withdrawal procedures between accessible mobile terminals by using the temporary friend list instead of a friend list according to a pre-registration such as a conventional instant messenger service. It can be effective.

The mobile terminal 200, 202, 204 uses an instant messenger service by transmitting and receiving instant messenger data with other mobile terminals 200, 202, 204 included in the temporary friend list provided from the mobile instant messenger server 100.

The mobile terminal 200, 202, 204 may directly transmit / receive instant messenger data with the counterpart mobile terminal 200, 202, 204 or via the mobile instant messenger server 100.

The operation of including the new mobile terminal 200 in the temporary friend list may include that the mobile terminal 200 enters the wireless communication enabled area of the mobile instant messenger server 100 or has already entered the communication available area. ) May be activated when the wireless communication function is activated or turned on. When the mobile instant messenger server 100 enables wireless communication with a new mobile terminal that is not included in the temporary friend list, the mobile instant messenger server 100 performs a procedure of checking whether to use a messenger service with the mobile terminal. Newly included in the list, the changed temporary friend list can be transmitted to all mobile terminals included in the temporary friend list.

The instant messenger data may be encrypted and transmitted based on at least one of a Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) protocol of IEEE 802.11i and a Temporal Key Integrity Protocol (TKIP) protocol of IEEE 802.11.

The mobile instant messenger server 100 may store the temporary friend list data in a storage means. The storage means includes a cache, a read only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), and a flash memory. Nonvolatile memory devices such as flash memory, volatile memory devices such as random access memory (RAM), and storage media such as hard disk drives, but are not limited thereto. Do not.

The temporary friend list data includes information for identifying each mobile terminal 200, 202, 204 on the instant messenger service, connection state data, and connection disconnection time data of the mobile terminal. The information that can be identified may include an ID of a user, a MAC address and an IP address of the mobile terminal.

The IP address may be a private Internet Protocol (IP) address temporarily generated by the mobile instant messenger server 100 or a public Internet Protocol (IP) address. When the IP address is a private IP address, the mobile instant messenger server 100 may understand that it must support a NAT (Network Address Translation) function for processing of traffic transmitted and received with the corresponding mobile terminal through an external network. There will be.

The mobile instant messenger server 100 may store the temporary friend list data in a storage means.

The storage means may include a cache, a read only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), and a flash memory (ROM). Nonvolatile memory devices such as flash memory, volatile memory devices such as random access memory (RAM), and storage media such as hard disk drives may be implemented as at least one of, but are not limited thereto. .

The mobile instant messenger server 100 previously removes the mobile terminals 200, 202, and 204 included in the temporary friend list from the temporary friend list when the mobile instant messenger server 100 is temporarily disconnected from the mobile instant messenger server 100. A grace period may be suspended for a defined waiting period for removal. On the contrary, when the connection with the mobile terminal is disconnected for a time exceeding the removal waiting period, it will be understood that the mobile terminal should be removed from the temporary friend list. The postpone to remove from the friend list during the removal waiting period is to eliminate the inconvenience of having to reconnect to the messenger service in case of temporary disconnection in the intermittent wireless communication environment. It will be appreciated that the removal waiting period may be compared with the connection disconnection time data included in and managed by the temporary friend list data.

The ad hoc instant messenger system according to the present embodiment waits for a while even when communication between the instant messenger server 100 and the mobile terminals 200, 202, and 204 is not smooth. Only by removing the corresponding mobile terminal from the friend list, even if the connection is temporarily disconnected in the intermittent communication environment, it is possible to solve the problem of logging out to the messenger.

(2) Replacement of Mobile Instant Messenger Server

Hereinafter, an operation of transferring the function of the mobile instant messenger server 100 to the next server 200 will be described. When the mobile instant messenger server 100 decides to transfer the function of the server to another mobile terminal, for example, when there is an input of the user's disable of server function, the system resource of the mobile instant messenger server is used to determine the function of the server. If it is insufficient to perform, it may be the case that the power of the mobile instant messenger server 100 is turned off. When the system resources become insufficient to perform the function of the server, for example, when the remaining capacity of the storage means is insufficient, the remaining power amount may be insufficient to perform the function of the server.

If the mobile instant messenger server 100 decides to transfer the function of the server to another mobile terminal, the mobile instant messenger server 100 may be selected from among the mobile terminals included in the temporary friend list before ending the operation of the instant messenger server. The status of the mobile instant messenger server is transferred to one mobile terminal 200 selected as a server. Hereinafter, the operation related to the replacement of the mobile instant messenger server of the ad hoc instant messenger system according to the present embodiment will be described with reference to FIG. 3. 3 is a signal flow diagram of a mobile instant messenger server replacement related operation of an ad hoc instant messenger system.

The mobile instant messenger server 100 transmits a server execution request signal to all mobile terminals 200, 202, and 204 included in the temporary friend list before ending the operation of the instant messenger server (S300).

When the mobile terminal 200, 202, or 204 receives the server performance request signal, the mobile terminal 200, 202, 204 determines whether to support the server performance, and if it is determined to support the mobile terminal 200, 202, 204, transmits the server performance support signal to the mobile instant messenger server (S302). . The mobile terminal 200, 202, or 204 may generate a user interface for requesting confirmation of server support, and determine that support is provided only when there is an input of server support from a user through the user interface. In addition, the mobile terminals 200, 202, and 204 may determine whether to support the performance of the server by referring to a setting value of an option for whether to automatically support the server. The server performance assistance signal may include access information of the mobile terminals 200, 202, and 204 that have transmitted the server performance assistance signal. The access information may be included in the server performance support signal by the wireless communication interface provided in the mobile terminal. The access information may be, for example, a MAC address or an IP address of the mobile terminal.

The mobile instant messenger server 100 selects one mobile terminal as a next server from among mobile terminals which have transmitted a server execution support signal corresponding to the server execution request signal (S304).

Hereinafter, the method of selecting the next server (S304) will be described.

First, when there is no server candidate terminal that transmits the server performance support signal, the mobile instant messenger server 100 may transmit an instant messenger service stop signal to all mobile terminals included in the temporary friend list.

On the other hand, if there is one server candidate terminal that has transmitted the server performance support signal, the mobile instant messenger server 100 selects the server candidate terminal as a next server.

When there are two or more server candidate terminals that transmit the server performance support signal, the mobile instant messenger server 100 selects a next server based on a device performance comparison of the server candidate terminals, or the terminal included in the temporary friend list. The next server may be selected by voting by the mobile terminal excluding the server candidate terminal. Alternatively, the next server may be selected by a combination of the device performance comparison and voting. For example, voting may be performed among the mobile terminals 200, 202, and 204 having a predetermined reference performance or more through the device performance comparison.

When the next server selection (S304) is performed through the device performance comparison of the server candidate terminal, the server candidate terminals 200, 202, and 204 move the server performance support signal including their performance data to the mobile instant messenger server 100. (S302) is preferable.

The performance data may include performance data of a central processing unit (CPU) of each mobile terminal 200, 202, 204, storage means remaining space data, area data of a communication area, and residual power amount data. The performance data of the central processing unit may be clock data, for example, and the area data of the communication area may be communication radius data according to the type of a wireless communication interface to support.

That is, the mobile instant messenger server 100 may compare at least one of performance data of the central processing unit of each server candidate terminal, storage means remaining space data, area data of the communication area, and residual power amount data.

The mobile instant messenger server 100 is a mobile instant messenger among the tied server candidate terminals when the server candidate terminal that transmits the server performance support signal is 2 or more, and a tie server candidate terminal having the same score is generated according to the criterion. One next server may be selected based on at least one of a sequence of accessing the server 100 and a distance from the mobile instant messenger server 100. For example, a mobile terminal that is connected to the mobile instant messenger server 100 first among the tie server candidate terminals or located closest to the mobile instant messenger server 100 may be selected as the next server 200. .

When the next server is selected (S304), the mobile instant messenger server 100 transmits a selection notification signal to the next server 200 (S306).

The next server 200 receiving the selection notification signal activates the instant messenger server function (S308). Activating the instant messenger server function (S308) may be understood as an operating system (OS) of the next server 200 executing the server module.

After activating the server function, the next server 200 generates a NPSK (New Pre-Shared Key) that the mobile terminals 202 and 204 to access should know.

The next server 200 that has activated the server function (S308) transmits a server execution ready signal (S310) to the mobile instant messenger server 100. The NPSK is stored in the server execution ready signal.

When the execution ready signal is received, the instant messenger server 100 transmits a server change notification signal including the NPSK stored in the execution ready signal to the mobile terminals 202 and 204 (S311). As a result, the next server 200 can securely transmit the NPSK generated by the current server to the mobile terminals 202 and 204 through the instant messenger server 100, and the abnormal mobile terminal not included in the temporary friend list data is NPSK. Since it is not possible to pass the mutual authentication between the next server 200, there is an effect that can apply the security of the access control method to the ad hoc instant messenger system. At least one of an L2 address and an L3 address of the next server 200 may be further stored in the server change notification signal. For example, at least one of a media access control (MAC) address and an IP address of the next server 200 may be further stored. The instant messenger server 100 transmits the server change notification signal to the general-purpose instant messenger server 300. Can also be sent. As illustrated in FIG. 2, the instant messenger server 100 may transmit the server change notification signal to the general-purpose instant messenger server 300 via the network 400 connected through the 2G / 3G mobile communication network. The NPSK may be stored in the server change notification signal.

The general instant messenger server 300 may update the address of the next server 200 and the NPSK value of the next server 200 by receiving the server change notification signal. The update may be performed on mobile instant messenger server list data managed by the general-purpose instant messenger server 300. The mobile instant messenger server list data corresponds to identification information and NPSK value for each mobile instant messenger server. It may be data being stored. The identification information of the mobile instant messenger server may be, for example, an L2 address.

The update related operation will be described by way of example. When the mobile instant messenger server 100 having the L2 address 'A' receives the information indicating that the L2 address of the next server 200 is 'B' and the NPSK value is '123' in the server change notification signal, The universal instant messenger server 300 updates the data having identification information 'A' included in the mobile instant messenger server list data with identification information 'B' and NPSK with '123', respectively.

When the next server 200 operates as a server, when the mobile terminal running the client module of the instant messenger service according to the present invention enters the communication area of the next server 200, the mobile terminal is the next server 200. In order to connect to), the NPSK providing request signal containing the L2 address of the next server 200 is transmitted to the universal instant messenger server 300 through 2G / 3G mobile communication, and the general instant messenger server 300 receives the received message. The NPSK value is retrieved from the mobile instant messenger server list data using the L2 address of the next server 200 stored in the received NPSK request signal as identification information, and then the retrieved NPSK value is transmitted to the mobile terminal for 2G / 3G mobile communication. You can send it through

The mobile terminal can receive an ad hoc instant messaging service by mutually authenticating and accessing the next server 200 using the NPSK received from the general-purpose instant messenger server 300. The instant messenger server 100 After transmitting the temporary friend list data in response to the server execution ready signal (S312), the instant messenger server function may be deactivated (S320).

Deactivating the instant messenger server function may be understood as an operating system (OS) of the mobile instant messenger server 100 terminating execution of the server module. More specifically, it may be understood to terminate execution of a process or thread associated with the server module on the operating system.

The instant messenger server 100 may transmit the temporary friend list data including the data about itself to the next server 200. That is, the instant messenger server 100 may be a mobile terminal using an instant messenger service after transferring the operation of the server to the next instant messenger server 200. In FIG. 3, it should be noted that the instant messenger server 100 does not use the instant messenger service while terminating the function of the server.

When the temporary friend list data is received (S312), the next server 200 transmits an access request signal to all mobile terminals 202 and 204 included in the temporary friend list data (S314). The access request signal preferably includes a PSK request message.

The mobile terminals 202 and 204 may access the next server 200 by performing mutual authentication using the NPSK provided from the mobile instant messenger server 100 (S316).

The next server 200 transmits a terminal access completion signal to the mobile instant messenger server 100 when all mobile terminals included in the temporary friend list data are connected (S316) (S318).

As shown in FIG. 3, the mobile instant messenger server 100 may deactivate the instant messenger server function after receiving the terminal access completion signal (S320). In this case, the server function of the mobile instant messenger server 100 is deactivated only after all mobile terminals included in the temporary friend list are connected to the next server 200, thereby providing a seamless messenger service to the mobile terminal. have.

Hereinafter, a case in which the mobile instant messenger server 100 operates as a proxy server of the general purpose instant messenger server 300 during the operation of the ad hoc instant messenger system according to the present embodiment will be described.

The mobile terminal constituting the instant messenger system according to the present embodiment may further support a second wireless communication interface different from the wireless communication interface used between the mobile terminals. For example, the second wireless communication interface may be at least one of Code Division Multiple Access (CDMA), Wideband Code Divisional Multiple Access (WCDMA), Global System for Mobile communications (GSM), and IEEE 802.16.

The mobile instant messenger server 100 and the next server 200 may be connected to the existing universal instant messenger server 300 through the second wireless communication interface to operate as a proxy server of the universal instant messenger server. .

When the mobile instant messenger server 100 and the next server 200 operate as a proxy server of the conventional general instant messenger server 300, the mobile terminals 200, 202, and 204 connected to the mobile instant messenger server 100 are provided. May transmit and receive instant messenger data with another terminal included in a friend list of the existing instant messenger service. Another terminal included in the friend list of the existing instant messenger service may be the mobile terminals 200, 202, and 204 connected to another mobile instant messenger server. At this time, it will be understood that the other mobile instant messenger server should also operate as a proxy server of the instant messenger server 300.

On the other hand, the user of the mobile instant messenger server 100 also transmits and receives instant messenger service data with the mobile terminals 200, 202, and 204 connected to their devices using the instant messenger service provided by the mobile instant messenger server 100. can do. To this end, the server module included in the mobile instant messenger server 100 preferably provides a self-login function. In this case, the temporary friend list may include the mobile instant messenger server 100.

As described above, the mobile instant messenger server 100 and the next server 200 further support a second wireless communication interface different from the wireless communication with the mobile terminal, and are connected to the general instant messenger server through the second wireless communication interface. When operating as a proxy server of the universal instant messenger server 300, the mobile instant messenger server 100 sends a proxy server change signal to the universal instant messenger server 300 including the connection information of the next server 200. It can transmit (S322). It should be noted that the next server 200 other than the mobile instant messenger server 100 may transmit a proxy server change signal including connection information of the next server 200 to the general-purpose instant messenger server 300 (S322). .

The mobile instant messenger server 100 and the next server 200 may use the proxy of the other instant messenger server only when at least one of the mobile terminals included in the temporary friend list data is a service subscriber provided by the other instant messenger server. proxy) It can also act as a server. Through such a configuration, an excessive 2G / 3G mobile communication fee can be prevented from being imposed on the mobile instant messenger server.

When the replacement of the mobile instant messenger server occurs, the instant messenger server 100 may transmit the server change notification signal to the general instant messenger server 300. As illustrated in FIG. 2, the instant messenger server 100 may transmit the server change notification signal to the general-purpose instant messenger server 300 via the network 400 connected through the 2G / 3G mobile communication network. The NPSK may be stored in the server change notification signal. That is, the second air interface may be understood to mean a 2G / 3G mobile communication network.

The general instant messenger server 300 may update the address of the next server 200 and the NPSK value of the next server 200 by receiving the server change notification signal. The update may be performed on mobile instant messenger server list data managed by the general-purpose instant messenger server 300. The mobile instant messenger server list data corresponds to identification information and NPSK value for each mobile instant messenger server. It may be data being stored. The identification information of the mobile instant messenger server may be, for example, an L2 address.

The update related operation will be described by way of example. When the mobile instant messenger server 100 having the L2 address 'A' receives and transmits the information that the L2 address of the next server 200 is 'B' and the NPSK value is '123', the server change notification signal. The universal instant messenger server 300 updates the identification information 'A' included in the mobile instant messenger server list data with identification information 'B' and NPSK with '123', respectively.

When the next server 200 operates as a server, when the mobile terminal running the client module of the instant messenger service according to the present invention enters the communication area of the next server 200, the mobile terminal is the next server 200. In order to connect to), the NPSK providing request signal containing the L2 address of the next server 200 is transmitted to the universal instant messenger server 300 through 2G / 3G mobile communication, and the general instant messenger server 300 receives the received message. The NPSK value is retrieved from the mobile instant messenger server list data using the L2 address of the next server 200 stored in the received NPSK request signal as identification information, and then the retrieved NPSK value is transmitted to the mobile terminal for 2G / 3G mobile communication. You can send it through

The mobile terminal can receive an ad hoc instant messaging service by accessing the next server 200 through mutual authentication using the NPSK received from the general-purpose instant messenger server 300.

Hereinafter, an ad hoc instant messenger service management method according to another embodiment of the present invention will be described with reference to FIG. 4. 4 is a flowchart illustrating an operation for replacing a mobile instant messenger server of an ad hoc instant messenger system according to an embodiment of the present invention. It should be noted that the technical features of the present invention described in the ad hoc instant messenger system according to the embodiment may be applied to the method for managing the ad hoc instant messenger service according to the present embodiment.

First, when a mobile terminal currently performing an ad hoc instant messenger server function can no longer perform an ad hoc instant messenger server function (S400), a temporary friend including the mobile terminal in a wireless communication state with the ad hoc instant messenger server is available. Initiate the deactivation procedure of the ad hoc instant messenger server function for the list.

Next, one of the mobile terminals included in the temporary friend list is selected as the next server. In the selection, a server execution request signal is transmitted to all mobile terminals included in the temporary friend list (S402), and a server next to one mobile terminal among the mobile terminals that transmits a server execution support signal corresponding to the server execution request signal. In operation S406, the method may include transmitting a selection notification signal to the next server in operation S408.

When the number of server candidate terminals transmitting the server performance support signal is 2 or more, at least one criterion of the device performance comparison of the server candidate terminal and voting by the mobile terminal except the server candidate terminal among the terminals included in the temporary friend list Next, the next server can be selected (S406). However, when the device performance comparison of the server candidate terminal is included in the criterion, the server performance support signal preferably includes performance data of the server candidate terminal.

If there is no server candidate terminal that has transmitted the server performance support signal (S404), the mobile messenger service is stopped after transmitting an instant messenger service stop signal to all mobile terminals included in the temporary friend list (S420). In operation S422, the service instant message may be notified to the general-purpose instant messenger server. Through this operation, it is possible to prevent the messenger service from being abruptly interrupted without any notification to the mobile terminal using the instant messenger service.

In deactivating the ad hoc instant messenger server function, when a server execution completion signal is received from the next server (S410), after transmitting the temporary friend list data in response (S412), the instant messenger server function is activated. Can be disabled. Deactivation of the instant messenger server function is preferably performed when a new connection of the mobile terminal to the next server is completed and a terminal connection completion signal is received from the next server. The temporary friend list data may include data about the mobile instant messenger server. That is, the instant messenger server may be a mobile terminal using an instant messenger service after transferring the operation of the server to the next instant messenger server.

Next, after activating the instant messenger server function of the next server, the ad hoc instant messenger server function is deactivated.

Hereinafter, an ad hoc instant messenger service management method according to another embodiment of the present invention will be described. It should be noted that the method for managing an ad hoc instant messenger service according to the present embodiment may also apply the technical features of the present invention described in the ad hoc instant messenger system according to the embodiment.

First, when the mobile terminal receives the server performance request signal (S402), it determines whether to support the server performance. The determination may be made by generating a user interface for confirming whether or not the server is supported, and determining that the support is provided only when there is an input of server support from the user through the user interface. In addition, the determination may be made through an operation of determining whether to support the execution of the server with reference to a setting value of an option for whether to automatically support the server.

Next, when it is determined that support for server performance is determined as a result of the determination, a server performance support signal is transmitted.

Next, when the selection notification signal is received (S408), the instant messenger server function is activated to generate a NPSK (New Pre-Shared Key) to be provided in the mutual authentication process when the mobile terminal wants to access the next server. After that, the server executes a ready signal for executing the NPSK and transmits the signal (S410).

The current instant messenger server receives the server execution ready signal and transmits the NPSK stored in the server execution ready signal to all mobile terminals included in the temporary friend list data (S411). The NPSK may be received and transmitted in a server change notification signal indicating that the server has been changed.

Thereafter, the instant messenger server transmits data of the temporary friend list to the next server in response to the server execution ready signal (S412).

Next, when the temporary friend list data is received (S412), the access request signal is transmitted to all mobile terminals included in the temporary friend list data (S414). The access request signal may include a message requesting to inform the PSK, and the mobile terminal may access the next server through mutual authentication with the next server using the NPSK provided from the instant messenger server (S414).

When there is at least one user of the universal instant messenger service among mobile terminals connected to the next ad hoc instant messenger server in response to the access request signal (S416), that is, the ad hoc instant messenger server operates as a proxy server of the general instant messenger server. In the case of doing so, the next ad hoc instant messenger server notifies the universal instant messenger server of the change of the proxy server (S418).

Hereinafter, a method for starting an ad hoc instant messenger service according to another embodiment of the present invention will be described. It should be noted that the technical features of the present invention described in the ad hoc instant messenger system according to the embodiment may also be applied to the method of starting the ad hoc instant messenger service according to the present embodiment. It will be appreciated that the method for starting an ad hoc instant messenger service according to the present embodiment is a method for selecting the first mobile instant messenger server when there is no mobile instant messenger server.

First, an IM message joining request signal is transmitted to a mobile terminal in a wireless communication area. The participation request signal may be transmitted in the form of broadcasting.

Next, in response to the instant messenger service participation request signal, a list of mobile terminals that transmit a participation signal is generated. Upon receiving the instant messenger service participation request signal, an operation of determining whether to transmit the participation signal may be additionally performed. The determination may be made by generating a user interface for confirming whether or not to participate in the instant messenger service, and determining that the support is provided only when there is an input of the instant messenger service participation from the user through the user interface. In addition, the determination may be made through an operation of determining whether to transmit the participation signal with reference to a setting value of an option for whether to automatically participate.

Next, one of the mobile terminals included in the list is selected as the mobile instant messenger server. The selection may be performed through an operation of selecting the mobile instant messenger server based on at least one of a performance comparison of a mobile terminal included in the list and a voting by the mobile terminal included in the list. In this case, when the device performance comparison of the mobile terminal included in the list is included in the criterion, the participation signal preferably includes performance data of the mobile terminal.

Next, the selection notification signal including the list of the mobile terminal is transmitted to the mobile instant messenger server.

Next, when the selection notification signal is received, after activating the instant messenger server function, the access request signal is transmitted to all mobile terminals included in the list of the mobile terminals.

Next, the list data is transmitted to all mobile terminals included in the list of the mobile terminals.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1 is a block diagram of a wireless instant messenger system using a mobile router.

2 is a diagram showing the configuration before and after the mobile instant messenger server change of the ad hoc instant messenger system according to an embodiment of the present invention.

3 is a signal flow diagram of a mobile instant messenger server replacement related operation of an ad hoc instant messenger system according to an exemplary embodiment of the present invention.

4 is a flowchart illustrating an operation for replacing a mobile instant messenger server of an ad hoc instant messenger system according to an embodiment of the present invention.

Claims (14)

A mobile instant messenger server having a server module for providing an instant messaging service to a mobile terminal included in a temporary friend list; And Transmitting instant messenger data between other terminals included in the temporary friend list, and when the mobile instant messenger is transferred to the next server, accessing the next server by performing mutual authentication using NPSK provided from the mobile instant messenger server. Including mobile terminals, The temporary friend list is composed of a mobile terminal in a wireless communication state with the mobile instant messenger server, The server module installed in the mobile instant messenger server, At the end of execution of the server module, transfer the status of the mobile instant messenger server to the mobile terminal selected as the next server among the mobile terminals included in the temporary friend list, and generate the NPSK (New Pre-Shared Key) generated by the next server. Ad-hoc instant messenger system for providing all mobile terminals included in the temporary friend list. The method of claim 1, The mobile instant messenger server, Before the execution of the server module, one of the mobile terminals that has transmitted a server performance request signal to all mobile terminals included in the temporary friend list and has transmitted a server performance support signal corresponding to the server performance request signal Selected as the next server, The mobile terminal, Ad-hoc instant messenger system, upon receiving the server execution request signal, determines whether or not to support server performance and, if determined to support, transmits the server performance support signal to the mobile instant messenger server. The method of claim 1, The mobile instant messenger server, Sending a selection notification signal to the next server, when the server ready to run server with the NPSK is received from the next server, the NPSK is transmitted to all mobile terminals included in the temporary friend list, the next server Ad-hoc instant messenger system to terminate execution of the server module after transmitting the temporary friend list data to the. The method of claim 3, The next server, When the selection notification signal is received, the server module is executed to generate the NPSK, and then the server execution ready signal including the NPSK is transmitted to the mobile instant messenger server, and the temporary friend list data is received. If so, Ad-hoc instant messenger system for transmitting a connection request signal to all mobile terminals included in the temporary friend list data. 5. The method of claim 4, The access request signal is an Ad-hoc instant messenger system including a Pre-Shared Key (PSK) request message. The method of claim 1, The mutual authentication is, Ad-hoc instant messenger system based on WPA-Personal procedure of Institute of Electrical and Electronics Engineers (IEEE) 802.11i. The method of claim 1, The instant messenger data, Ad-hoc instant messenger system encrypted and transmitted based on at least one of the CCMP (Counter mode with Cipher block chaining Message authentication code Protocol) protocol of IEEE 802.11i and the Temporal Key Integrity Protocol (TKIP) protocol of IEEE 802.11 . The method of claim 1, The mobile instant messenger server, After transmitting the temporary friend list data and receiving a terminal access completion signal from the next server, deactivating the instant messenger server function, The next server, An ad hoc instant messenger system for transmitting the terminal access completion signal to the mobile instant messenger server when all mobile terminals included in the temporary friend list data are connected. The method of claim 1, The mobile instant messenger server and the next server, Further supports a second wireless communication interface different from the wireless communication with the mobile terminal, is connected to a universal instant messenger server via the second wireless communication interface to operate as a proxy server of the universal instant messenger server, One of the mobile instant messenger server and the next server, Ad-hoc instant messenger system for transmitting a proxy server change signal including connection information of the next server to the general-purpose instant messenger server. 10. The method of claim 9, The mobile instant messenger server and the next server, An ad hoc instant messenger system operating as a proxy server of the universal instant messenger server only when at least one of the mobile terminals included in the temporary friend list data is a service subscriber provided by the universal instant messenger server. The method of claim 1, The mobile instant messenger server further supports a second wireless communication interface different from the wireless communication with the mobile terminal, and sends an identification information of the next server and a server change notification signal containing the NPSK to a universal instant messenger server. Instant messenger system. 12. The method of claim 11, The mobile terminal, When the next server is found, the NPSK request signal containing the identification information of the next server is transmitted to the general-purpose instant messenger server. When the NPSK is received in response, the next server is mutually communicated with the next server using the received NPSK. An ad hoc instant messenger system that performs authentication. Selecting, by the mobile instant messenger server, one of the mobile terminals included in the temporary friend list as a next server, and transmitting a selection notification signal to the next server; Receiving, by the next server, a New Pre-Shared Key (NPSK) generated when the selection notification signal of the next server is received from the next server and providing it to all mobile terminals included in the temporary friend list; And Performing the mutual authentication by the mobile terminal using the next server and the NPSK, The temporary friend list is a security method of the ad hoc instant messenger system comprises a mobile terminal in a state capable of wireless communication with the mobile instant messenger server. When the mobile terminal of the ad hoc instant messenger system receives a server performance request signal from the mobile instant messenger server, it determines whether to support the server performance. When the selection notification signal is received from the messenger server, activating an instant messenger server function, and generating a NPSK (New Pre-Shared Key) and providing it to the mobile instant messenger server; When the temporary friend list data is received from the mobile instant messenger server, the mobile terminal of the ad hoc instant messenger system accesses all mobile terminals included in the temporary friend list data with a PSK request message. Transmitting a request signal; And And the mobile terminal of the ad hoc instant messenger system performing mutual authentication with the mobile terminal included in the temporary friend list data using the NPSK.

Images