KR100250976B1 - Detection and managment method of terminal copying in wireless communication service - Google Patents

Abstract

The present invention provides a method of detecting and managing mobile communication service terminal duplication which detects and manages duplication much more accurately than when using only COUNT comparison when temporary secret key duplication or permanent secret key duplication occurs. By detecting this immediately when a terminal is copied by an illegal user, it is possible to eradicate illegal activities such as terminal duplication, and also to reduce the operator's work burden or the number of operation personnel by automatically controlling the authentication failure when operating the authentication center. In addition, since the sensitivity of the terminal duplication is very high, unnecessary interference to the subscriber can be reduced, thereby contributing to improved customer service.

Description

Detection and Management Method of Mobile Service Terminal Duplication

The present invention relates to a method for detecting and managing mobile communication service terminal duplication, and more particularly, to a method for detecting and managing various terminal duplications that may occur in a public mobile communication system such as a PCS and cellular having an authentication function. It is about.

The authentication function in the specification of the present invention refers to a semi-permanent secret key (A-Key) and a temporary secret key (SSD) generated from both the mobile communication terminal and the mobile communication network, such as IS-41C. And a function of authenticating the terminal using an authentication response (AUTHR: AUTHentication Response) generated therefrom.

In the specification of the present invention, the term "terminal duplication" means to inject all or part of various authentication related information of a legitimate subscriber terminal into another terminal and use it.

Authentication in mobile communication is introduced to prevent various kinds of illegal use which appeared as a big problem in the existing analog cellular service, and the illegal use is made in various ways, and the main method is terminal cloning.

Terminal duplication is a method of eavesdropping the identification information of a legitimate subscriber terminal on a wireless channel, that is, a mobile identification number (MIN) and an electronic serial number (ESN), and inputting it to a new terminal. There is also a method of extracting identification information directly from the subscriber terminal and injecting it into another terminal.

In order to prevent such illegal use, the second generation digital mobile communication systems all have their own authentication functions. Two of them are the authentication method of Global System for Mobile communication (GSM), a pan-European digital cellular system, and the authentication method of IS-41C, a standard for North American digital cellular systems.

GSM generates Signed Response (SRES) directly from semi-permanent secret key (Ki), while IS-41C (AUTHR) passes through temporary secret key (SSD) from semi-permanent secret key (A-Key). Is generated.

In addition, the IS-41C has a feature of detecting a case where there is a terminal duplicated to a secret key by using a count as a parameter for recording a call history.

In the case of GSM, if there is a duplicate terminal injecting all identification information including a semi-permanent secret key (Ki), there is no way to detect or block it. However, since GSM implements Subscriber Identification Module (SIM) as a smart card and stores a secret key inside it, it is more difficult to duplicate the terminal. .

On the other hand, since IS-41C authentication method or similar authentication method uses COUNT, it is true that it is more likely to detect when terminal replication occurs, but it is impossible to be sure that replication is generated only by count. have. This is because the possibility of a COUNT mismatch between a legitimate subscriber station and a communication network may not be excluded due to an error in the terminal, a wireless section, or a communication network.

In view of the prior art described above, the present invention provides a method for detecting and managing a copy much more accurately than when using only a COUNT comparison when a temporary secret key copy or a permanent secret key copy occurs. An object of the present invention is to provide a method for detecting and managing duplication of a mobile communication service terminal.

1 is a diagram illustrating a terminal authentication procedure in a public mobile communication network to which the present invention is applied.

FIG. 2 is a diagram illustrating a process of performing a terminal authentication procedure within a terminal and a mobile communication network shown in FIG.

3 is a flowchart illustrating a method of detecting and managing a duplicate of a mobile communication service terminal according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a process of processing an authentication discrepancy mismatch shown in FIG.

FIG. 5 is a flowchart showing a count mismatch process shown in FIG.

FIG. 6 is a flow chart showing the temporary secret key copy management process shown in FIG.

* Explanation of symbols for main parts of the drawings

10: terminal 20: mobile communication network

A method for detecting and managing duplication of a mobile communication service terminal of the present invention for achieving the above object comprises: a first process of transmitting a first authentication response and a first count value from a specific terminal to a standby mobile communication network; A second step of calculating a second authentication response and a second count value corresponding to the terminal in the mobile communication network which received the value, and comparing each other; A third step of allowing the terminal to access the mobile communication network in a first case in which the comparison result of the authentication response and the count value are the same; If there is a mismatch as a result of the comparison of the authentication response, denial of network connection of the terminal, and then perform authentication response mismatch processing on the terminal attempting to reconnect to detect whether network access is allowed and terminal duplication according to the update result of the temporary secret key. The fourth process; When the result of the authentication response comparison is matched, the respective count values are compared. If the count values do not match, denial of network connection of the terminal is performed, and count mismatch processing is performed on the terminal to be reconnected to update the temporary secret key. And a fifth process of detecting whether network access is allowed and terminal duplication according to the result.

Basically assumed in the present invention, like the IS-41C, the mobile communication network and the terminal obtains the same temporary secret key (SSD) from the same secret key (A-Key) to obtain an authentication response (AUTHR) by using the same, In addition, a "temporary secret key renewal" protocol is provided in which a terminal and a mobile communication network go through a series of protocols and obtain a new temporary secret key different from the previous temporary secret key (SSD).

The basic fact that can be seen from the result of the temporary secret key update is that the successful terminal has the same secret key as the A-Key of the mobile communication network, while the failed terminal has the same secret key as the mobile communication network. Is not.

In addition, a feature of the present invention is that the number of occurrences of a COUNT mismatch can be recorded so that an operator can refer to whether or not duplication has occurred, but it is not used as a basis for decisive judgment. Instead, more accurate duplication detection is possible using patterns of authentication failures and patterns of temporary secret key update results.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating a terminal authentication procedure in a public mobile communication network to which the present invention is applied. FIG. 2 is a diagram illustrating a signal transmission between a terminal and a mobile communication network in FIG. 10) and the mobile communication network 20 distributes / stores the same subscriber authentication secret key (A-Key) immediately after joining through a secure method of security and performs a temporary secret key (SSD) renewal procedure immediately before the authentication procedure is performed. The same temporary secret key is also stored.

Subsequently, when the terminal 10 accesses the mobile communication network 20, an authentication response (AUTHR) is generated by using a random number, a temporary secret key (SSD), and other parameters sent by the mobile communication network 20. This is sent to the mobile communication network (20).

The mobile communication network 20 calculates an authentication response (AUTHR) through the same generation process using the information related to the corresponding terminal stored by the mobile communication network 20 and checks whether it is the same as the authentication response (AUTHR) sent by the terminal 10.

In this case, the mobile communication network 20 checks whether the count COUNT, which is a parameter related to the call history sent by the terminal 10, with the count stored in the mobile communication network 20, and checks whether the values are the same. do. In the two comparison processes, if the calculation results of the terminal 10 and the mobile communication network 20 are the same, authentication is successful.

In FIG. 2, as an input of an algorithm for obtaining a temporary secret key (SSD), other parameters (for example, random number, device serial number (ESN), etc.) are input in addition to the secret key (A-Key) shown in the drawing. Can be used as a value.

In addition to the temporary secret key (SSD) and the random number, the device serial number (ESN), the terminal identifier (MIN), the called number, and the like may be used as input values of the algorithm for obtaining the authentication response (AUTHR).

In addition, the random number in the figure may be any of two authentication challenges specified in IS-41C, that is, a global challenge and a unique challenge.

3 is a flowchart illustrating a method for detecting and managing duplication of a mobile communication service terminal according to an embodiment of the present invention. Referring to this, the method of the present invention will be described below.

When the mobile communication network 20 is placed in the standby state (step 30) and an authentication request message is received from the terminal 10 (step 31), the mobile communication network 20 receives an authentication parameter (i.e., authentication) included in the authentication request message. The response (AUTHR) and the count (COUNT) are obtained inside the mobile communication network 20 and then compared with the corresponding parameters (step 32).

As a result of the comparison, if the authentication is the same, authentication is considered to be successful, and network connection to the terminal 10 is allowed (step 33), and the state is returned to the standby state again. It is checked if it is a response (AUTHR) mismatch (step 34).

As a result of the verification, if the authentication response (AUTHR) is inconsistent, the authentication response mismatch processing is performed accordingly (step 35). If the authentication response (AUTHR) is not inconsistent, the count (COUNT) is inconsistent. The count mismatch process is performed (step 36).

The authentication response mismatch processing operation will be described in detail with reference to the flowchart of FIG. 4 as follows.

When the authentication response (AUTHR) mismatch processing operation is started, the number of occurrence counters (not shown) of the event (first event) called "authentication response (AUTHR) mismatch" is first increased (+1) (step 40).

The result is then compared with a predetermined threshold (e.g., 3) (step 41), if it is less than that threshold (step 42) and the authentication response mismatch processing operation is terminated, whereas If not small, the counter is reset to " 0 " (step 43), and an attempt is made to update the temporary secret key (SSD) for the terminal 10 (step 44).

As a result of the update attempt (step 45), if the terminal 10 fails to update the temporary secret key (SSD), the network connection to the terminal 10 is rejected (step 46) and the authentication response mismatch processing is terminated.

On the contrary, if the renewal attempt is successful, the network access to the terminal 10 is allowed (step 47), and the number of occurrences of this event, that is, the event (second event) of "successful temporary secret key update after authentication response mismatch" (second event) The counter (not shown) is incremented (+1) (step 48).

Then, the increased result is compared with a predetermined threshold (e.g., 2) (step 49), and if the comparison result is less than the threshold, the authentication response mismatch processing is terminated, while the secret value is not less than the threshold. A-Key duplication is considered to occur and an alarm or report to the operator (step 50).

On the other hand, in the overall operation description of the present invention described with reference to the flowchart of FIG. 3, the count mismatch processing operation will be described based on the flowchart of FIG.

When the count mismatch processing operation is started, the number of occurrence counters (not shown) of the event (the third event) called "count mismatch" is first increased (+1) (step 60).

Subsequently, the result value is compared with a predetermined threshold (e.g., 3) (step 61) and if the threshold value is smaller than the threshold value, the network connection to the terminal 10 is rejected (step 62) and the count mismatch processing is terminated. If the count is not smaller than the threshold, the counter is reset to " 0 " (step 63), and an attempt is made to update the temporary secret key (SSD) for the terminal 10 (step 64).

As a result of the update attempt (step 65), if the terminal 10 succeeds in updating the temporary secret key (SSD), the network connection to the terminal 10 is allowed (step 66) and "temporary secret key update succeeded after count mismatch". The count mismatch processing is terminated after incrementing (+1) the occurrence count counter (not shown) of the event (fourth event).

On the contrary, if the attempt to renew the temporary secret key (SSD) fails, the network access to the terminal 10 is rejected (step 68) and the temporary secret key (SSD) copy management operation is performed (step 69). The mismatch processing ends.

Here, the temporary secret key (SSD) duplication management operation will be described with reference to the flowchart of FIG.

First, the mobile communication network 20 waits until the authentication request (step 71) comes from the corresponding terminal 10 in the waiting state (step 70).

When the authentication request comes, the authentication parameters (authentication response, count) are compared with the internally generated authentication parameters (step 72), and when all of the comparison results match, the temporary secret key (SSD) is updated for the terminal 10. Is attempted (step 73).

As a result of the update attempt (step 74), if it fails, the network access to the terminal 10 is rejected (step 75), and the temporary secret key (SSD) copy is reported to the operator (step 76). Return to the standby state of.

On the contrary, if the attempt to renew the temporary secret key (SSD) is successful, the network access to the terminal 10 is allowed (step 77), and the temporary secret key (SSD) copy is reported to the operator (step 78). Terminate temporary secret key replication management.

On the other hand, if the authentication parameters between the terminal 10 and the mobile communication network 20 is not the same in the comparison of the authentication parameters in step 72, first it is confirmed whether the authentication response (AUTHR) mismatch (step 79), the confirmation As a result, if the authentication response is inconsistent with each other, after performing the authentication response mismatch processing operation described with reference to FIG. 4 (step 80), the process returns to the standby state again.

However, if the authentication responses do not match each other in step 79, it is regarded as a count mismatch, so that the number of occurrence counters (not shown) of an event (count 3) called "count mismatch" is increased (+1). (Step 81).

Subsequently, the increased result value (count value) is compared with a predetermined threshold value (for example, 3) (step 82), if it is smaller than the threshold value, the network connection to the terminal 10 is rejected (step 83), and waiting again. It will return to the state.

On the contrary, if the result value is not smaller than the threshold, the counter is reset to "0" (step 84) and an attempt is made to update the temporary secret key (SSD) for the terminal 10 (step 85).

As a result of the update attempt (step 86), when the terminal 10 fails to update the temporary secret key (SSD), it denies the network connection to the terminal 10 (step 87) and returns to the standby state. If the temporary secret key (SSD) update is successful, the network connection to the terminal 10 is allowed (step 88) and the temporary secret key duplication management is terminated.

The temporary secret key duplication management operation of FIG. 6 detects a temporary secret key (SSD) duplication for a legitimate terminal 10 and then attempts to access the mobile communication network 20. By denying the network connection and updating the temporary secret key (SSD) for the legitimate terminal 10, the temporary secret key duplication state is released.

As described in detail above, according to the present invention, it is possible to eradicate illegal activities such as terminal duplication by immediately detecting a terminal duplication by an illegal user, as well as by automatically controlling authentication failure when operating an authentication sensor. This can reduce the workload and the number of operational personnel.

In addition, since the sensitivity of the terminal duplication is very high, unnecessary interference on the subscriber can be reduced, thereby contributing to the improvement of customer service.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (5)

A first step of transmitting a first authentication response and a first count value from a terminal to a mobile communication network; A second step of calculating a second authentication response and a second count value corresponding to the terminal in the mobile communication network which received the value, and comparing each other; A third step of allowing the terminal to access the mobile communication network in a first case in which the comparison result of the authentication response and the count value are the same; If there is a mismatch as a result of the comparison of the authentication response, denial of network connection of the terminal, and then perform authentication response mismatch processing on the terminal attempting to reconnect to detect whether network access is allowed and terminal duplication according to the update result of the temporary secret key. Fourth process; And comparing each count value when the authentication response comparison result is matched, rejecting the network connection of the terminal when the count value does not match, and performing count mismatch processing on the terminal attempting to reconnect. And a fifth process of detecting whether network access is allowed and terminal duplication according to the update result. The method of claim 1, wherein the first and second authentication responses are calculated using random numbers, temporary secret keys, and authentication parameters in the mobile communication network. The method of claim 1, wherein the step of processing an inconsistency of the authentication response in the fourth process comprises: a first step of first increasing the 'authentication response inconsistency event occurrence counter' and comparing it with a preset threshold; A second step of denying a network connection if it is less than a threshold as a result of the comparison, resetting the counter and attempting to update a temporary secret key for the corresponding terminal if it is larger; A third step of denying the network access to the corresponding terminal if the update attempt fails, allowing the network connection if the update attempt succeeds, and increasing a temporary secret key update success event occurrence count counter according to an authentication response mismatch; Comparing the increased event counter value with a predetermined threshold value, if the threshold value is less than the threshold value, terminating the authentication response mismatch process; Detection and management method. The method of claim 1, wherein the count mismatch processing step of the fifth process comprises: a first step of increasing a count mismatch event occurrence counter and then comparing the count mismatch with a preset threshold; Rejecting, if greater, resetting the counter and attempting to update a temporary secret key for the terminal; A third step of denying network access to a corresponding terminal if the update attempt fails, and performing temporary secret key duplication management on the retryed terminal; And a fourth step of allowing a network connection if the update attempt is successful, incrementing a temporary secret key update success event occurrence count counter due to a count mismatch, and then ending a count mismatch process. Method for detecting and managing service terminal duplication. 5. The method of claim 4, further comprising the steps of: performing temporary secret key duplication management in the third step, comparing authentication parameters with each other when an authentication request is received from a terminal in a mobile communication network and then comparing the authentication parameters with each other; Denying the network connection if it fails as a result of the update attempt, and reporting the temporary secret key copy to the operator after allowing the network connection if the update attempt succeeds; Checking the authentication response and count mismatch if the authentication parameters are not the same; Performing authentication response mismatch processing when the verification result is inconsistent, and increasing the 'count mismatch event occurrence count counter' when the verification result is inconsistent, and comparing it with a preset threshold value; Denying the network connection if it is less than a threshold as a result of the comparison; resetting the counter and attempting to update a temporary secret key for the corresponding terminal if greater; And denying the network access to the terminal if the update attempt fails, and terminating the temporary secret key duplication management after allowing the network access if the update attempt is successful. Way.

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