KR100971568B1 - Method of authenticating subscriber information in a mobile communication system - Google Patents

Abstract

A method of verifying subscriber information in a 3G mobile communication system for verifying subscriber information using an encryption method is disclosed. The method for verifying subscriber information comprises encrypting a first identifier (IDENTITY) using a specific encryption method to generate a first encryption value, and obtaining from a core network in response to the generated first encryption value and specific identifier information (IDENTITY_RECORD_SET_NUMBER). And encrypting the second identifier using the encryption method to generate a second encryption value, and comparing the first encryption value with the second encryption value to determine the integrity of the subscriber information. The generating of the second cipher value may include transmitting the generated first cipher value and the specific identifier information IDENTITY_RECORD_SET_NUMBER to a specific signal RRC_CONNECTION REQUSET to transmit to the wireless access network UTRAN. Obtaining the second identifier from the core network in response to a particular signal and encrypting the obtained second identifier to generate the second cryptographic value.

Password, IDENTITY, IMSI, IMEI, HASH

Description

How to check subscriber information in mobile communication system {METHOD OF AUTHENTICATING SUBSCRIBER INFORMATION IN A MOBILE COMMUNICATION SYSTEM}

The present invention relates to a method for verifying subscriber information in a mobile communication system, and more particularly, a first cipher value generated by encrypting an identifier and a second cipher value generated by encrypting an identifier obtained from a core network. The present invention relates to a method for verifying subscriber information by comparing the subscriber information with each other.

Asynchronous 3GPP (Wireless Code Division Multiplex Access) type asynchronous 3GPP (3G Generation) mobile communication system includes a user equipment (UE), a node B, a radio network control station (Radio). Network Controller (RNC), Service GPRS Supporting Node (SGSN) and Gateway MSC (GMSC).

The mobile communication system transmits IMSI stored in the terminal to the VLR / SGSN to confirm subscriber information. Here, the VLR / SGSN means a VLR managing subscriber location information of the SGSN. That is, in the mobile communication system, the IMSI associated with the subscriber information is transmitted as it is without encryption to confirm the subscriber information. This is based on the standard 3GPP Spec. 33.102, which relates to the security design of 3GPP.

However, when the IMSI is directly transmitted without encryption as described above, another person may hack the IMSI during the signal transmission process, so that the subscriber information may be illegally used by the other person.

SUMMARY OF THE INVENTION An object of the present invention is to provide a subscriber information verification method for encrypting the identifier so that the identifier does not leak during the process of transmitting the identifier related to the subscriber information in the mobile communication system, and confirming the integrity of the subscriber information using the encrypted value. To provide.

In order to achieve the above object, in the mobile communication system according to an embodiment of the present invention, the method for confirming subscriber information security generates a first cipher value by encrypting a first identifier using a specific cipher method. step; Generating a second encryption value by encrypting the second identifier obtained from the core network using the encryption method in response to the generated first encryption value and specific identifier information IDENTITY_RECORD_SET_NUMBER; And comparing the first cipher value with the second cipher value to determine the integrity of the subscriber information. The generating of the second cipher value may include transmitting the generated first cipher value and the specific identifier information (IDENTITY_RECORD_SET_NUMBER) in a specific signal RRC_CONNECTION REQUSET to a wireless access network (UTRAN); Obtaining the second identifier from the core network in response to the specific signal transmitted; And encrypting the obtained second identifier to generate the second cipher value.

A method of encrypting subscriber information in a 3G mobile communication system according to an embodiment of the present invention comprises the steps of setting an encryption algorithm, BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET; Calculating an acceleration value by adding or subtracting the BITMAP_MASK_OFFSET from a digit corresponding to the BITMAP_MASK_VALUE in an identifier; And encrypting the additive value using the encryption algorithm.

Since the method for confirming subscriber information of a mobile communication system according to an embodiment of the present invention transmits a cipher value generated by encrypting an identifier in a RRC connection request to a UTRAN by including in a specific signal, illegal use of subscriber information by others There is an advantage that can be prevented.

In addition, since the method for confirming subscriber information of a mobile communication system according to an embodiment of the present invention changes IMSI / IMEI by using BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET, the IMSI / IMEI change value may be changed for each RRC connection. Backtracking of IMEI can be prevented.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a general WCDMA asynchronous 3G mobile communication system of the present invention.

Referring to FIG. 1, the 3G mobile communication system includes a mobile communication terminal (User Equipment), a wireless access network (UMTS Terrestrial Radio Access Network, UTRAN) and a core network (Core Network).

The mobile communication terminal (UE) includes a mobile equipment (ME) and a subscriber identity module (UMTS Suscriber Identity Module, USIM).

The ME stores IDENTITY_RECORD_SET_NUMBER, which is an identifier of an International Mobile Station Equipment Identity (IMEI), which will be described later.

The USIM stores a user's unique information and stores IDENTITY_RECORD_SET_NUMBER, which is an identifier of an International Mobile Station Identity (IMSI).

The UTRAN is a part connecting the UE and the core network, and includes a Radio Network Subsystem (RNS) including a Node B and a Radio Access Controller (RNC). For example, when the core network intends to provide a specific service to the terminal (UE), the core network transmits service related information to the terminal (UE) through the UTRAN.

The Node B is a device that is responsible for transmitting and receiving data through a radio interface, and performs a basic radio resource management function. For example, the Node B sets up a wireless physical channel necessary for data exchange with the UE according to the information transmitted from the RNC, converts data transmitted from a higher protocol into a wireless environment, and converts the data according to the wireless environment. To send.

The RNC controls components in the RNS to dynamically allocate radio resources of the UTRAN, and performs a switching function for transmitting data transmitted through the UTRAN to an appropriate node.

The core network includes Mobile Switched Center / Visiting Location Register (MSC / VLR) corresponding to circuit switched area, Gateway MSC (GMSC), Serving GPRS Supporting Node (SGSN) corresponding to packet switched area, and HLR corresponding to GMSC, register area. (Home Location Register), AuC (Authentication Center) and EIR (Equipment Identity Register), and is connected to a public switched telephone network (PSTN) or the Internet network.

The MSC / VLR manages a circuit-switched connection, performs mobility management such as location information update, location information registration, paging, and performs functions related to data security.

The GMSC serves as a connection path between a circuit switched area and a public telecommunication network, or serves as a connection path between a packet switched area and the Internet network.

The HLR stores permanent data of the subscriber, and the AuC stores data related to authentication.

The EIR maintains and manages identification information related to the hardware of the terminal.

In a mobile communication system having such a structure, a confirmation process of subscriber information is essential. However, the method for confirming subscriber information according to the present embodiment encrypts and transmits an identifier related to the subscriber information as described below so that others do not use the subscriber information illegally.

Hereinafter, a method of confirming subscriber information in the mobile communication system will be described with reference to the accompanying drawings.

2 is a block diagram schematically illustrating a mobile communication system related to a method for confirming subscriber information according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating subscriber information in the mobile communication system according to an embodiment of the present invention. It is a flowchart showing the process of confirmation. In this case, IMSI and IMEI may be used as the subscriber information, and a subscriber information confirmation process is required for each subscriber information.

Hereinafter, after confirming the subscriber information confirmation process for IMSI will be described in detail the subscriber information confirmation process for IMEI.

First, the subscriber information confirmation process for the IMSI will be described in detail.

2 and 3, the RNC 202 sets an encryption algorithm, BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET, and includes the set encryption algorithm, BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET in a system information message (SIB) for broadcasting. (S300). The BITMAP_MASK_VALUE is a value used to temporarily change the IMSI by designating a specific digit of the IMSI, and the BITMAP_MASK_OFFSET is a value added to or subtracted from the digit specified by the BITMAP_MASK_VALUE.

According to an embodiment of the present invention, the encryption algorithm uses a hash algorithm verified as an excellent security algorithm. Here, SHA1, MD5, RMD160 or TIGER may be used as the hash algorithm. Hereinafter, it is assumed that the hash algorithm is used as the encryption algorithm.

Subsequently, the terminal 200 determines the IMSI as an identifier associated with subscriber information, and detects a digit corresponding to the BITMAP_MASK_VALUE from an upper digit of a mobile subscriber identifier (MSIN) included in the IMSI. A sum value is calculated by adding the BITMAP_MASK_OFFSET to the detected digit. Here, the IMSI is a 15-digit identification number assigned to the mobile communication terminal when the mobile communication system is subscribed to the terminal. It includes.

Subsequently, the terminal 200 encrypts the calculated sum using the set hash algorithm to generate a first hash value (S302).

Thereafter, the UE UE includes the first hash value and IDENTITY_RECORD_SET_NUMBER in an RRC_CONNECTION_REQUEST message, which is a signal for RRC connection, and transmits the same to the RNC 202 (S304). The IDENTITY_RECORD_SET_NUMBER is information for identifying the IMSI and is stored in the USIM.

The RNC 202 then detects the IDENTITY_RECORD_SET_NUMBER from the transmitted RRC_CONNECTION_REQUEST message and sends an identifier type (IDENTITY_TYPE) and the IDENTITY_RECORD_SET_NUMBER to the VLR / SGSN 204. Here, the VLR / SGSN 204 means a VLR managing subscriber location information of the SGSN.

Subsequently, the VLR / SGSN 204 requests a search for the identifier using the identifier type IDENTITY_TYPE and the IDENTITY_RECORD_SET_NUMBER to obtain a second identifier (S306).

Thereafter, the VLR / SGSN 204 transmits the obtained second identifier to the RNC 202 (S308).

Subsequently, the RNC 202 encrypts the transmitted second identifier using the hash algorithm to calculate a second hash value (S310). In detail, the RNC 202 generates a sum value using the BITMAP_MASK_VALUE and the BITMAP_MASK_OFFSET, and encrypts the sum value using the hash algorithm to calculate the second hash value.

Subsequently, the RNC 202 compares the first hash value with the second hash value (S312).

When the first hash value and the second hash value are the same, that is, when the subscriber information is authenticated with correct information, the RNC 202 continuously performs an RRC access procedure (S314). In detail, the RNC 202 grasps the QoS level of the service according to the RRC_CONNECTION_REQUEST message and includes the terminal basic information, transmission channel information, and physical channel information in the RRC CONNECTION SETUP message and transmits the same to the terminal 200. In this case, the terminal 200 completes the setting of the lower layer according to the instruction of the RNC 202, and then transmits an RRC CONNECTION SETUP COMPLETE message to the RNC 202 that the setting is completed.

On the other hand, if the first hash value and the second hash value is not the same, if authentication for the subscriber information fails, the RNC 202 transmits an RRC_CONNECTION_REJECT message to the terminal 200, the received first 2 The identifier is discarded (S314).

Next, the subscriber information confirmation process for the IMEI will be described in detail.

The RNC 202 sets an encryption algorithm, BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET, and broadcasts the set encryption algorithm, BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET by including it in a system information message (SIB) (S300).

Subsequently, the terminal 200 determines the IMEI as an identifier, detects a digit corresponding to the BITMAP_MASK_VALUE from a lower digit of a serial number (SRN) included in the IMEI, and detects the digit in the detected digit. The absolute value of the calculated subtraction value is obtained by subtracting the BITMAP_MASK_OFFSET. Here, the IMEI is a 15-digit identification number assigned to the mobile communication terminals so that the mobile communication terminals can uniquely identify each other. The IMEI is a Type Allocation Code (TAC) and a Final Assembly Code (FAC). ) And a six digit serial number (SRN).

Subsequently, the subtracted value is encrypted using the set hash algorithm to calculate a first hash value (S302).

Thereafter, the UE UE includes the first hash value and IDENTITY_RECORD_SET_NUMBER in an RRC_CONNECTION_REQUEST message, which is a signal for RRC connection, and transmits the same to the RNC 202 (S304). The IDENTITY_RECORD_SET_NUMBER is information for identifying the IMEI and is stored in the ME.

The RNC 202 then detects the IDENTITY_RECORD_SET_NUMBER from the transmitted RRC_CONNECTION_REQUEST message and sends an identifier type (IDENTITY_TYPE) and the IDENTITY_RECORD_SET_NUMBER to the VLR / SGSN 204. Here, the VLR / SGSN 204 means a VLR managing subscriber location information of the SGSN.

Subsequently, the VLR / SGSN 204 requests a search for the identifier using the identifier type IDENTITY_TYPE and the IDENTITY_RECORD_SET_NUMBER to obtain a second identifier (S306).

Thereafter, the VLR / SGSN 204 transmits the obtained second identifier to the RNC 202 (S308).

Subsequently, the RNC 202 encrypts the transmitted second identifier using the hash algorithm to calculate a second hash value (S310).

Subsequently, the RNC 202 compares the first hash value with the second hash value (S312).

When the first hash value and the second hash value are the same, that is, when the subscriber information is authenticated with correct information, the RNC 202 continuously performs an RRC access procedure (S314).

On the other hand, if the first hash value and the second hash value is not the same, if authentication for the subscriber information fails, the RNC 202 transmits an RRC_CONNECTION_REJECT message to the terminal 200, the received first 2 The identifier is discarded (S314).

In short, the subscriber information confirmation method of the present invention transmits the first cipher value generated by encrypting IMSI / IMEI to the UTRAN, and the UTRAN requests the core network to receive IMSI / IMEI from the core network. The UTRAN then encrypts the received IMSI / IMEI to generate a second cipher value and compares the first cipher value with the second cipher value to determine the integrity of the subscriber information.

As described above, since the method for confirming subscriber information of the present invention encrypts IMSI / IMEI for authentication of subscriber information and then transmits the IMSI / IMEI to the UTRAN, it is possible to prevent unauthorized use of subscriber information by others in the process of transmitting a signal.

In addition, the method for confirming subscriber information according to the present invention detects a digit corresponding to the BITMAP_MASK_VALUE in IMSI / IMEI, and changes the IMSI / IMEI by adding or subtracting the BITMAP_MASK_OFFSET to the detected digit. As a result, the method for confirming subscriber information may generate different encryption values for each RRC connection for the same identifier. Therefore, it is possible to prevent backtracking of the actually assigned identifier.

According to another embodiment of the present invention, the subscriber information verification method may use an algorithm other than the hash algorithm, and may use another method without using the BITMAP_MASK_VALUE and the BITMAP_MASK_OFFSET. Of course, even in this case, the terminal 200 encrypts IMSI / IMEI to generate a first cipher value, transmitting the generated first cipher value to the UTRAN, and the UTRAN obtains an identifier from the core network. The process of generating the second cipher value is performed in the same way.

That is, the method for confirming subscriber information of the present invention obtains an identifier from the core network to confirm subscriber information, and generates a second encryption value that is compared with the first encryption value.

The embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention may make various modifications, changes, and additions within the spirit and scope of the present invention. Should be considered to be within the scope of the following claims.

1 is a block diagram illustrating a general WCDMA asynchronous 3G mobile communication system of the present invention.

2 is a block diagram schematically illustrating a mobile communication system associated with a method for confirming subscriber information according to an embodiment of the present invention.

3 is a flowchart illustrating a process of confirming subscriber information in the mobile communication system according to an embodiment of the present invention.

Claims (17)

In the method of confirming subscriber information security in a mobile communication system, Encrypting the first identifier (IDENTITY) using a specific encryption method to generate a first encryption value; Generating a second encryption value by encrypting the second identifier obtained from the core network using the encryption method in response to the generated first encryption value and specific identifier information IDENTITY_RECORD_SET_NUMBER; And Comparing the first cipher value with the second cipher value to determine integrity of subscriber information; Generating the second cipher value, Transmitting the generated first cipher value and the specific identifier information (IDENTITY_RECORD_SET_NUMBER) in a specific signal (RRC_CONNECTION REQUSET) to a wireless access network (UTRAN); Obtaining the second identifier from the core network in response to the specific signal transmitted; And And generating the second cipher value by encrypting the obtained second identifier. delete The method of claim 1, wherein the obtaining of the second identifier comprises: Transmitting, by the terminal, the signal RRC_CONNECTION REQUSET having the generated first cipher value and the identifier information IDENTITY_RECORD_SET_NUMBER to a radio network control station (RNC); The RNC sending an identifier type (IDENTITY_TYPE) and the identifier information (IDENTITY_RECORD_SET_NUMBER) to the VLR / SGSN of the core network; And The VLR / SGSN comprises the step of obtaining the second identifier by using the transmitted identifier type (IDENTITY_TYPE) and the identifier information (IDENTITY_RECORD_SET_NUMBER). The method of claim 1, wherein generating the second cryptographic value comprises: Transmitting the obtained second identifier to a radio network control station (RNC); And And the wireless network control station (RNC) encrypting the second identifier. The method of claim 1, wherein the encryption method uses a hash algorithm. 6. The method of claim 5, wherein the hash algorithm is one of SHA1, MD5, RMD160, and TIGER. The method of claim 1, wherein the method for confirming subscriber information comprises: Setting a hash algorithm (HASH_TYPE), BITMAP_MASK_VALUE, and BITMAP_MASK_OFFSET through a radio network controller (RNC); And And broadcasting the hash algorithm (HASH_TYPE), the BITMAP_MASK_VALUE, and the BITMAP_MASK_OFFSET in a system information message (SIB). 8. The method of claim 7, wherein generating the first cryptographic value comprises: If the first identifier corresponds to an international mobile station identification number (IMSI), selecting a digit corresponding to the BITMAP_MASK_VALUE from an upper digit of an MSIN included in the IMSI; Generating a sum value by adding the BITMAP_MASK_OFFSET to the selected digit; And And encrypting the sum value using the hash algorithm to generate the first encryption value. 8. The method of claim 7, wherein generating the first cryptographic value comprises: If the first identifier corresponds to an International Mobile Terminal Identification Number (IMEI), selecting a digit corresponding to the BITMAP_MASK_VALUE from a lower digit of a serial number (SRN) included in the IMEI; Generating a subtracted value by subtracting the BITMAP_MASK_OFFSET from the selected digit; And And encrypting the subtracted value by using the hash algorithm to generate the first cipher value. The method of claim 1, wherein the method for confirming subscriber information comprises: Attempting an RRC connection when the first cipher value and the second cipher value are the same; And And transmitting the RRC_CONNECTION_REJECT message to the terminal and discarding the second identifier when the first password value and the second password value are not the same. The method of claim 1, wherein the mobile communication system is a 3G mobile communication system. In a method of encrypting subscriber information in a 3G mobile communication system, Setting an encryption algorithm, BITMAP_MASK_VALUE and BITMAP_MASK_OFFSET; Calculating an acceleration value by adding or subtracting the BITMAP_MASK_OFFSET from a digit corresponding to the BITMAP_MASK_VALUE in an identifier; And And encrypting the deceleration value using the encryption algorithm. 13. The method of claim 12, wherein the encryption algorithm is a hash algorithm. 15. The method of claim 13, wherein the hash algorithm is one of SHA1, MD5, RMD160, and TIGER. The method of claim 12, wherein the calculating of the acceleration or decrease value comprises: If the identifier corresponds to an International Mobile Station Identification Number (IMSI), selecting a digit corresponding to the BITMAP_MASK_VALUE from an upper digit of an MSIN included in the IMSI; And And calculating the deceleration value by adding the BITMAP_MASK_OFFSET to the selected digit. The method of claim 12, wherein the calculating of the acceleration or decrease value comprises: If the identifier corresponds to an International Mobile Terminal Identification Number (IMEI), selecting a digit corresponding to the BITMAP_MASK_VALUE from a lower digit of a serial number (SRN) included in the IMEI; And And subtracting the BITMAP_MASK_OFFSET from the selected digit to calculate the deceleration value. The method of claim 12, wherein the encryption method is performed by a terminal in a 3G mobile communication system.

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