KR101042525B1 - Method and apparatus for preventing illegal tapping in wideband code division multiple access system - Google Patents

Abstract

Disclosed are a method and apparatus for preventing illegal eavesdropping in a WCDMA system. In accordance with an embodiment of the present invention, a method for preventing illegal eavesdropping includes determining whether to receive at least two RRC connection request messages including the same terminal information; And rejecting or releasing the at least two RRC connection requests when the at least two RRC connection request messages are received, and the determining may include determining the two RRC connection request messages for a predetermined time. The reception can be determined.

Eavesdropping, eavesdropping, pirated terminals, RRC (Radio Resource Control), WCDMA

Description

Method for preventing illegal eavesdropping in WCDMA system and its device {METHOD AND APPARATUS FOR PREVENTING ILLEGAL TAPPING IN WIDEBAND CODE DIVISION MULTIPLE ACCESS SYSTEM}

The present invention relates to the prevention of illegal eavesdropping, and more particularly, to the prevention of illegal eavesdropping in a WCDMA system that can prevent illegal eavesdropping / tapping in the process of establishing a radio resource control (RRC) connection in a wideband code division multiple access (WCDMA) system. A method and apparatus therefor.

WCDMA uses a wider bandwidth than a CDMA scheme that uses a pseudo noise code unique to a subscriber's communication channel.WCDMA is strong in frequency selective fading because of the wide bandwidth, and increases the processing gain by increasing bandwidth when transmitting the same data. Therefore, there is an advantage that the capacity is increased by reducing the interference as much.

In addition, since multipath can be resolved using a RAKE receiver, it is possible to overcome the propagation delay in the indoor environment even in the case of a micro cell, and has an excellent bandwidth efficiency per 1 [MHz] bandwidth, which is advantageous in terms of subscriber capacity and processing gain. The third generation communication system that has been adopted in Korea, Japan, and Europe in that the cost of implementation is reduced by increasing the capacity of the power amplifier and the power consumption and size of the terminal can be reduced by reducing the size of the power amplifier. to be.

Such a WCDMA technology has little probability of eavesdropping / tapping due to illegal copying, and can be filtered by Integrity Protection or Ciphering.

However, integrity verification or encryption is performed after the RRC connection setup is completed, and encryption may be turned off depending on the operating environment. In this case, if the same starting value has the same TMSI (Temporary Mobile Subscriber Identity), there is a possibility of eavesdropping / tapping and unnecessary signaling may occur because integrity verification is performed after signaling has been performed. Can be.

Accordingly, there is a need for a method that can reduce unnecessary signaling and reduce the likelihood of eavesdropping / tapping.

An object according to an embodiment of the present invention, which was devised to solve the above problems, is to prevent illegal eavesdropping in a WCDMA system which can reduce the possibility of eavesdropping / tapping by preventing eavesdropping / tapping due to illegal copying of terminals in the RRC setting step. A method and apparatus are provided.

Another object according to an embodiment of the present invention is to provide a method and apparatus for preventing illegal eavesdropping in a WCDMA system capable of reducing additional signaling by preventing eavesdropping / tapping in an RRC setting step.

In order to achieve the above object, the illegal eavesdropping prevention method according to an aspect of the present invention provides a method for preventing illegal eavesdropping in a WCDMA system, comprising: determining whether to receive at least two RRC connection request messages including the same terminal information; step; And rejecting or releasing the at least two RRC connection requests when the at least two RRC connection request messages are received.

Further, the determining may determine whether the at least two RRC connection request messages are received during a preset time.

Further, the determining may include extracting terminal information from the first RRC connection request message when a first RRC connection request message is received; Monitoring an RRC connection request message received for a preset time; And determining whether a second RRC connection request message including the same information as the terminal information extracted from the first RRC connection request message is received during the time.

In this case, the terminal information may include any one of a temporary mobile subscriber identity (TMSI), a packet TMSI (P-TMSI), an international mobile station identity (IMSI), and an international mobile station equipment identity (IMEI).

An illegal eavesdropping prevention device according to an aspect of the present invention includes an illegal eavesdropping prevention device in a WCDMA system, comprising: a determination unit determining whether to receive at least two RRC connection request messages including the same terminal information; And a determination unit for rejecting or releasing the at least two RRC connection requests when the at least two RRC connection request messages are received.

The determination unit may determine whether to receive the at least two RRC connection request messages for a preset time.

The apparatus may further include an extractor configured to extract corresponding terminal information from the RRC connection request message, and the determiner may determine whether to receive the at least two RRC connection request messages by comparing the terminal information extracted by the extractor. Can be.

Other objects and features of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, a method and apparatus for preventing illegal eavesdropping in a WCDMA system according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

Figure 1 shows an embodiment system for explaining the present invention.

Referring to FIG. 1, a system includes a first terminal 110, a second terminal 120, a Radio Transceiver Subsystem (RTS) 130, and a Radio Network Controller (RNC) 140. do.

The RTS 130 performs a wireless access termination function with the terminals 110 and 120 according to the 3GPP wireless access standard, and transmits and receives voice, video, and data traffic in a WCDMA manner, and transmits and receives a terminal 110 through a transmit / receive antenna. And 120 transmit and receive information.

In general, the internal subsystem of RTS 130 is comprised of a base-station interconnection subsystem, a base band subsystem, and a radio frequency subsystem. In addition, the RTS 130 is also used as the name 'Node B' in the 3GPP radio access standard.

The RNC 140 manages wired and wireless channels, protocol matching of a terminal, protocol matching of a base station, soft handoff processing, protocol matching with a core network, GPRS connection, fault management, system loading, and the like. The RNC 140 performs the same function, when the RRC connection request message is received from the terminal, for example, the first terminal 110 and the second terminal 120, the received RRC is received. The terminal information included in the connection request message is used to prevent eavesdropping / tapping caused by an illegal copy terminal in the RRC setup process.

Hereinafter, the first terminal will be defined as a normal terminal 110, and the second terminal will be described on the assumption that it is an illegal copy terminal 120.

In order to prevent eavesdropping / tapping of the normal terminal 110 by the illegal copy terminal 120 in the RRC setting process, the RNC 140 receives the RRC setting request message from the received RRC setting request message. Extracts the information, monitors the RRC setup request message received for a preset time, determines whether an RRC setup request message including the same terminal information is received during the preset time, and when received, eavesdropping / tapping by the illegal copying terminal 120. In response to the determination, the RRC configuration reject message is transmitted.

In this case, the terminal information may include any one of a temporary mobile subscriber identity (TMSI), a packet TMSI (P-TMSI), an international mobile station identity (IMSI), and an international mobile station equipment identity (IMEI).

The monitoring time of the RRC setup request message set in the RNC 140 may be determined by the time taken to transmit the setup message for the RRC connection request message to the corresponding terminal, and further, the time required to receive the RRC connection request message transmitted from the terminal. It may be further determined by the delay time.

For example, the RRC connection request transmitted from the illegal copy terminal 120 until the RRC connection request message is received from the normal terminal 110 and a setup message for the RRC connection request message is transmitted to the normal terminal 110 after a preset time. If no message is received, the eavesdropping / tapping by the illegal copying terminal 120 is not performed, and if an RRC connection request message transmitted from the illegal copying terminal 120 is received before the setup message is transmitted to the normal terminal 110, The setup message for the RRC connection request message may be received by the illegal copy terminal 120 as well as the normal terminal 110 to intercept / tap the normal terminal. Of course, illegal eavesdropping / tapping is possible only when the normal terminal and the illegal terminal are located in the same cell.

Therefore, in order to prevent such eavesdropping / tapping in the RRC setting process, the RNC sets up after receiving the RRC setting request message for a predetermined time after receiving the RRC connection request message from the normal terminal 110. When the RRC connection request message including the same terminal information as the normal terminal 110 is received during the time taken to transmit the message, that is, the RRC connection request transmitted from the illegal copy terminal 120 illegally copying the normal terminal 110. When the message is received, by transmitting a rejection message for the RRC connection request messages transmitted from the two terminals (110, 120), to prevent the use of the normal terminal 110 and illegal copy terminal 120 to prevent eavesdropping / eavesdropping .

Of course, depending on the situation, the RRC configuration may be rejected only for the terminal that transmits the second RRC connection request message.

In addition, the RNC 140 monitors the time required to prevent eavesdropping / tapping by the counterfeit terminal after receiving the RRC connection request message, and the time until the RRC connection request message is transmitted to the setup message after receiving the RRC connection request message. It may also be set by adding a delay time for receiving the RRC connection request message sent from.

This is the case where the RRC connection request message is transmitted from the illegal copy terminal 120 but not received by the RNC 140 before the RNC 140 sends the setup message for the RRC connection request message to the normal terminal 110. Because it can occur. That is, if the RNC 140 sets the monitoring time to the time from the reception of the RRC connection request message to the transmission of the setup message, due to the transmission delay time from the illegal copy terminal 120 to the RNC 140, the illegal copy terminal ( When the setup message is transmitted in a state in which the RRC connection request message transmitted from 120 is not received, the counterfeit terminal 120 receives the setup message together with the normal terminal 110, so that the counterfeit terminal 120 receives the setup message. The terminal 110 can be tapped / tapted.

Accordingly, the RNC 140 takes a delay time for receiving the RRC connection request message transmitted from the counterfeit terminal 120 for a monitoring time for preventing eavesdropping / tapping by the counterfeit terminal 120 in preparation for such a case. It is preferable to set in consideration of this. Here, the delay time may vary depending on the distance between the counterfeit terminal 120 and the RNC 140, but may be set in consideration of the corresponding cell area, which may distract the gist of the present invention. Description is omitted.

Furthermore, if the normal terminal 110 does not receive the setup message from the RNC 140 after transmitting the RRC connection request message, the normal terminal 110 retransmits the RRC connection request message after a certain time, until such a case. In consideration of the above, it is preferable to set the determination time (or monitoring time) in the RNC 140. That is, it is preferable that the determination time set in the RNC 140 does not exceed the time taken to retransmit the RRC connection request message from the normal terminal 110. Therefore, when the determination time set in the RNC 140 is set to be equal to or longer than the time required for retransmission of the RRC connection request message, the RNC 140 requests two RRC connection requests transmitted from the normal terminal 110 instead of the counterfeit terminal 120. A case of receiving a message may occur, and in this case, a rejection message for the RRC connection request message transmitted from the normal terminal may be transmitted even though the normal terminal is not intercepted / tapted. In order to prevent such a case, the determination time or monitoring time in the present invention may be set to be smaller than the time taken to retransmit the RRC connection request message after the terminal transmits the RRC connection request message.

The RNC 140 receives an RRC connection request message and transmits a setup message to the normal terminal 110 to connect the core network (CN) 150, which is a higher network, to the normal terminal 110. To allow the process to follow up.

At this time, the core network 150 includes a Serving GPRS Support Node (SGSN), a Gateway GPRS Support Node (GGSN), an authentication server and a billing server, which are upper networks of the RNC 140. can do.

As described above, since the RNC in the present invention can prevent eavesdropping / tapping by the counterfeit terminal in the RRC setup step, it is possible to reduce signaling additionally accompanied by the counterfeit terminal, and also by tapping the integrity verification and encryption function. By performing first order filtering before eavesdropping is filtered, the potential for eavesdropping / tapping can be minimized.

If necessary, the terminal subscriber may be informed that the terminal is being illegally exploited, thereby reducing the damage of the subscriber due to illegal theft. The information on illegal theft may be a text message such as a short message, a telephone call or It is possible to prevent illegal theft through a method such as replacing a universal subscriber identity module (USIM) by providing the subscriber to the terminal through e-mail.

FIG. 2 illustrates an embodiment configuration for the RNC shown in FIG. 1.

Referring to FIG. 2, the RNC 140 includes a receiver 210, an extractor 220, a determiner 230, and a determiner 240.

The receiver 210 receives an RRC connection request message received by the RNC 140. That is, the RRC connection request message transmitted from the normal terminal 110 and the RRC connection request message transmitted from the illegal copy terminal 120 are received.

The extractor 220 extracts terminal information, for example, any one of TMSI, P-TMSI, IMSI, and IMEI from the RRC connection request message received by the receiver 210.

The determination unit 230 determines whether the RRC connection request message including the same information as the terminal information extracted by the extraction unit 220 is received for a predetermined time or determination time.

That is, the determination unit 230 receives the RRC from the illegal duplication terminal 120 that illegally duplicates the normal terminal within a predetermined time to prevent eavesdropping / tapping after the RRC connection request message transmitted from the normal terminal 110 is received. Determine whether a connection request message is received.

When the determination unit 230 receives two RRC connection request messages with the same terminal information for a predetermined time, the determination unit 240 transmits the two RRC connection request messages including the same terminal information. The RRC connection rejection message or the RRC connection release message is transmitted to the terminal 110 and the illegal copy terminal 120.

In this case, the determination unit 240 transmits an RRC connection rejection message when both the normal terminal 110 and the illegal copy terminal 120 are not connected to the RRC, and in the state where the setup message is transmitted to the normal terminal 110, the determination unit 240 is normal. The RRC connection release message may be transmitted to the terminal 110, and the RRC connection rejection message may be transmitted to the illegal copy terminal 120.

In addition, the determination unit 240 may transmit the RRC connection rejection message by setting a connection rejection cause and a waiting time. The waiting time may be set by a default value and may be changed by an operator. At this time, the default value of the waiting time may be set to "0" in order to eliminate repetition.

The operation in such an RNC will be described in detail with reference to FIG. 3 as follows.

3 is an exemplary diagram for explaining an illegal eavesdropping prevention device according to the present invention.

As shown in FIG. 3, when the RNC as an illegal eavesdropping device receives an RRC connection request message from a normal terminal, an RRC connection request including the same terminal information as the normal terminal for a preset time period from the time when the RRC connection request message is received. Determine if a message is received.

At this time, when the RRC connection request message is received from the illegal copy terminal having the same terminal information as the normal terminal within the set time (①), the RRC connection rejection message is transmitted to the normal terminal and the illegal terminal, thereby tapping the normal terminal from the illegal terminal. To prevent eavesdropping;

Of course, if the RNC receives a RRC connection request message transmitted from the counterfeit terminal after the set time (②), the setup message is already transmitted to the normal terminal before receiving the RRC connection request message received from the counterfeit terminal. As a result, the counterfeit terminal cannot intercept / tap the normal terminal.

As described above, the illegal eavesdropping prevention device according to an embodiment of the present invention minimizes the possibility that a normal terminal can be intercepted / listened by the illegal copying terminal in the RRC setting step, and further includes an illegal copying terminal that is additionally included after the RRC setting step. Signaling can also be reduced. In addition, by providing information indicating that the terminal is illegally stealed to the corresponding terminal subscriber, damage to the terminal subscriber due to illegal theft may be reduced.

4 is a flowchart illustrating a method for preventing illegal eavesdropping according to an embodiment of the present invention.

Referring to FIG. 4, the illegal eavesdropping prevention method receives an RRC connection request message transmitted from a terminal and extracts terminal information included in the received RRC connection request message (S410 and S420).

In this case, the terminal information may include any one of TMSI, P-TMSI, IMSI, and IMEI.

The RRC connection request message is transmitted from the terminals for a preset time, for example, a set time or a determination time, from the time at which the RRC connection request message is received (S430).

Of course, it is obvious to extract the terminal information for the received RRC connection request message.

In this case, the monitoring time, that is, the setting time or the determination time may be determined by the time from when the RRC connection request message is received to the time for transmitting the setup message to the terminal, and according to the situation until the setup message is transmitted. In addition to the time, it may be determined by the delay time for receiving the RRC connection request message transmitted from the terminal. Of course, the monitoring time is not limited to the above two cases and can be determined by all factors that must be considered to prevent eavesdropping / tapping by the counterfeit terminal.

It is determined whether two RRC connection request messages including the same terminal information are received through the monitoring in step S430 (S440).

That is, after receiving the RRC connection request message transmitted from the normal terminal, it is determined whether the RRC connection request message transmitted from the illegal copy terminal illegally copied the normal terminal is received.

In other words, after extracting the terminal information from the RRC connection request message of the normal terminal, and extracts the terminal information of the RRC connection request message received for a predetermined time, whether at least two or more RRC connection request messages including the same terminal information is received. To judge.

As a result of determination in step S440, when at least two or more RRC connection request messages including the same terminal information are received during the monitoring time, i. The RRC connection rejection message or the RRC connection release message is transmitted to the terminals that have transmitted the RRC connection request message including the SRC.

Of course, if it is determined in step S440 that another RRC connection request message including the same terminal information is not received for a predetermined time, by transmitting a setup message for the RRC connection request to the corresponding terminal and receiving a completion message therefor. To complete the RRC setup process for the terminal.

As described above, the illegal eavesdropping prevention method according to an embodiment of the present invention can prevent eavesdropping / tapping by the illegal copying terminal in the RRC setting process, thereby reducing signaling additionally accompanied by the illegal copying terminal, and RRC. In the setting step, by the first filtering on the tapping / tapping, and the second filtering by the existing integrity verification and encryption function, the possibility of tapping / tapping by the counterfeit terminal can be minimized.

In addition, the method and apparatus for preventing illegal eavesdropping according to an embodiment of the present invention have been described as being limited to a case where there is only one illegal copy terminal, but a plurality of illegal copy terminals may be used to intercept / tap the normal terminal. It is also applicable to the illegal copy terminal.

The method and apparatus for preventing illegal eavesdropping in a WCDMA system according to the present invention can be modified and applied in various forms within the scope of the technical idea of the present invention, and are not limited to the above embodiments. In addition, the embodiments and drawings are merely for the purpose of describing the contents of the invention in detail, not intended to limit the scope of the technical idea of the invention, the present invention described above is common knowledge in the technical field to which the present invention belongs As those skilled in the art can have various substitutions, modifications, and changes without departing from the spirit of the present invention, it is not limited to the embodiments and the accompanying drawings. And should be judged to include equality.

Figure 1 shows an embodiment system for explaining the present invention.

FIG. 2 illustrates an embodiment configuration for the RNC shown in FIG. 1.

3 is an exemplary diagram for explaining an illegal eavesdropping prevention device according to the present invention.

4 is a flowchart illustrating a method for preventing illegal eavesdropping according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: normal terminal

120: illegal copy terminal

140: radio control station (RNC)

Claims (11)

In the method of preventing illegal eavesdropping in a WCDMA system, Determining whether to receive at least two RRC connection request messages including the same terminal information for a predetermined time determined by a time taken to transmit a setup message for the RRC connection request message; And Rejecting or releasing the at least two RRC connection requests when the at least two RRC connection request messages are received; Illegal eavesdropping prevention method comprising a. delete The method of claim 1, The determining step Extracting terminal information from the first RRC connection request message when a first RRC connection request message is received; Monitoring an RRC connection request message received for a preset time; And Determining whether a second RRC connection request message including the same information as the terminal information extracted from the first RRC connection request message is received during the time; Illegal eavesdropping prevention method comprising a. The method according to any one of claims 1 to 3, The terminal information is A method for preventing illegal eavesdropping including any one of a temporary mobile subscriber identity (TMSI), a packet TMSI (P-TMSI), an International Mobile Station Identity (IMSI), and an International Mobile Station equipment Identity (IMEI). The method according to any one of claims 1 to 3, The step of releasing If the setup message for the RRC connection request message is transmitted, the illegal eavesdrop prevention method for releasing the RRC connection for the terminal to which the setup message is sent. delete The method of claim 5, The preset time is The illegal eavesdropping prevention method is determined in consideration of the delay time for receiving the RRC connection request message transmitted from the terminal. The method according to any one of claims 1 to 3, Rejecting or releasing the RRC connection request and transmitting a message including a cause and a waiting time for the RRC connection request; Illegal eavesdropping method comprising more. In the illegal eavesdropping prevention apparatus in the WCDMA system, A determination unit that determines whether to receive at least two RRC connection request messages including the same terminal information for a predetermined time determined by a time taken to transmit a setup message for the RRC connection request message; And A determination unit for rejecting or releasing the at least two RRC connection requests when the at least two RRC connection request messages are received; Illegal wiretap prevention device comprising a. delete 10. The method of claim 9, Extraction unit for extracting the terminal information from the RRC connection request message More, The determination unit And comparing the terminal information extracted by the extracting unit to determine whether the at least two RRC connection request messages are received.

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