KR100546778B1 - Method and apparatus for authentication in wireless internet system - Google Patents

Abstract

The present invention relates to a wireless internet subscriber authentication method and apparatus for providing mutual authentication between a subscriber and a network in a wireless internet network and sharing a key therebetween, wherein the authentication server is based on a secret key and a first random number. Generates RES1, which is information used for authentication of the network, and generates XRES2, which is information used for authentication of a subscriber, based on the secret key and the second random number, and the mobile terminal generates the network from the secret key and the first random number. Generates XRES1, authentication information, and compares XRES1 with RES1 to authenticate the network, and generates RES2, subscriber authentication information, from the secret key and the second random number, and prevents unauthorized users from using the network. And by authenticating the server itself to prevent leakage of subscriber's personal information by a fake server, and to provide more secure communication with longer keys. The.

Wireless internet, user authentication, authentication server, mobile terminal

Description

Wireless internet subscriber authentication method and apparatus therefor {Method and apparatus for authentication in wireless internet system}

1 is a configuration diagram of a mobile communication network using a SIM and a wireless Internet network according to the present invention.

2 shows a protocol for mutual authentication between a mobile terminal and a wireless internet network.

3 is a diagram illustrating a data format of a TNAI.

4 is a block diagram illustrating the operation of AAAH.

5 is a block diagram of an apparatus for performing a network authentication process in a mobile terminal.

The present invention relates to a wireless internet subscriber authentication method and apparatus for providing mutual authentication between a subscriber and a network in a wireless internet network and sharing a key therebetween.

In general, subscriber authentication in the wireless Internet is performed using an ID / password method, which has two problems. The first is that it has a fatal weakness in terms of security because the password is transmitted unencrypted. The second is that it authenticates the subscriber only to the network side but does not provide the function of authenticating the network to the subscriber. It does not provide authentication. Therefore, subscribers are always exposed to the risk of ID / password theft, and there is a risk that their personal information is leaked by a fake server.

The technical problem to be achieved by the present invention is to minimize the number of messages exchanged between the subscriber and the network in the mutual authentication of the wireless Internet network, and to add a separate device and algorithm to the existing Subscriber Identity Module (SIM) structure The present invention provides a wireless Internet subscriber authentication method and apparatus for enabling authentication by simple modification without addition.

In the wireless Internet subscriber authentication method according to the present invention for achieving the above technical problem, the mobile terminal is connected to the wireless Internet through the gateway, the gateway connected to the wireless Internet network (Agent Advertisement: AA) Broadcasting a message to its subnetwork; When the mobile terminal enters the subnetwork, transmitting a network access identifier (NAI) including a first random number and an International Mobile Subscriber Identity (IMSI) to the gateway; The gateway separating the subscriber identifier and the first random number and transmitting the same to the authentication server; The authentication server extracts a secret key using the subscriber identifier, generates RES1 based on the secret key and the first random number, and generates XRES2 based on the secret key and the second random number; The authentication server transmits the RES1, the second random number, and the XRES2 to the gateway; The gateway storing XRES2 and transmitting the RES1 and the second random number to the mobile terminal; Generating a XRES1 using a secret key and a first random number stored in the mobile terminal, and then comparing the XRES1 with the RES1 received from the gateway to authenticate the network; Generating a RES2 from the secret key and the second random number received from the gateway, and then transmitting the RES2 to the gateway; And the gateway comparing the RES2 received from the mobile terminal with the XRES2 stored therein to authenticate the subscriber.

The wireless Internet subscriber authentication apparatus according to the present invention for achieving the above technical problem, when entering into the sub-network of the gateway, transmits the network access identifier including the first random number and the subscriber identifier to the gateway, the secret key and the internal stored A mobile terminal for generating an XRES1 using one random number and then authenticating the network by comparing the XRES1 with the RES1 received from the gateway, generating a RES2 from a secret key and a second random number received from the gateway, and then transmitting the RES2 to the gateway; Broadcasts the agent advertisement message to its subnetwork, separates the subscriber identifier and the first random number from the network access identifier received from the mobile terminal entering its subnetwork, sends it to the authentication server, and receives the XRES2 received from the authentication server. A gateway for transmitting the RES1 and the second random number to the mobile terminal, and comparing the RES2 received from the mobile terminal with the XRES2 stored therein to authenticate the subscriber; And extracting a secret key using the subscriber identifier, generating RES1 based on the secret key and the first random number, generating XRES2 based on the secret key and the second random number, and then calculating RES1, the second random number, and XRES2. Contains an authentication server that sends to the gateway.

Also, the authentication server generates a first encryption key based on the secret key and the first random number, generates a second encryption key based on the secret key and the second random number, and then joins the first and second encryption keys. The third encryption key is generated and transmitted to the gateway, the gateway stores the third encryption key, and the mobile terminal generates the fourth encryption key using the secret key and the first random number stored therein, A fifth encryption key is generated based on a second random number, and then a fourth encryption key is generated by concatenating the fourth and fifth encryption keys. The third encryption key generated by the authentication server and the mobile terminal are generated. The sixth encryption key preferably shares the same value.

The authentication server according to the present invention for achieving the above technical problem, Secret key extraction unit for extracting a secret key using the received user identifier; A first signal generator for generating RES1, which is information used for authentication of a network in a first encryption key and a mobile terminal, based on the secret key and the received first random number; Random number generation unit for generating a second random number; A second signal generator for generating an XRES2, which is information used for authentication of a second encryption key and a subscriber, based on the secret key and the second random number; And an encryption key generation unit for generating a third encryption key by joining the first encryption key and the second encryption key.

In accordance with an aspect of the present invention, there is provided a network authentication apparatus for a mobile terminal, the apparatus for receiving a RES1 and a second random number and performing a network authentication process in the mobile terminal. The random number for generating a first random number. Generation unit; A first signal generator for generating XRES1 and first encryption keys, which are network authentication information, from a secret key and a first random number stored therein; A comparison unit for authenticating a network by comparing the XRES1 with the received RES1; A second signal generator for generating subscriber authentication information RES2 and a second encryption key from the secret key and the received second random number; And an encryption key generation unit for generating a third encryption key by joining the first encryption key and the second encryption key.

Another wireless Internet subscriber authentication method according to the present invention for achieving the above technical problem, the FA connected to the wireless Internet network continuously broadcasts the AA message to its subnetwork according to the mobile IP protocol; When the mobile terminal enters the subnetwork of the FA, the mobile terminal recognizes the AA message and sends a network access identifier including the first random number and the subscriber identifier to the FA and the HA; The HA separates the subscriber identifier and the first random number and sends it to AAAH; The AAAH extracts a secret key using the subscriber identifier, generates a first encryption key and RES1 based on the secret key and the first random number, and generates a second encryption key and XRES2 based on the secret key and the second random number. And joining the first and second encryption keys to generate a third encryption key; AAAH transmits the RES1, the second random number, the XRES2, and the third encryption key to HA and FA; FA stores the XRES2 and the third encryption key and transmits the RES1 and the second random number to the mobile terminal; Generating a XRES1 and a fourth encryption key using a secret key and a first random number stored therein, and then authenticating the network by comparing the XRES1 with the RES1 received from the FA; The mobile terminal generates the RES2 and the fifth encryption key from the secret key and the second random number received from the FA, then transmits the RES2 to the FA, and concatenates the fourth and fifth encryption keys to generate a sixth encryption key. ; And FA comparing the RES2 received from the mobile terminal with the XRES2 stored therein to authenticate the subscriber. The FA includes a third encryption key generated in the authentication server and a sixth encryption key generated in the mobile terminal. It is desirable to share a value.

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

1 is a diagram illustrating an interworking configuration of a mobile communication network using a SIM and a wireless Internet network according to the present invention. In FIG. 1, the SIM 11 is inserted into and used in the mobile terminal 10.

When used in a mobile communication network, a mobile station 10 receives subscriber authentication from a home location register (HLR) via a base station (12) and a mobile switching center (MSC) 13. When the mobile terminal 10 is used in a wireless Internet network, authentication, authorization & accounting server in home side connected to an HA (Home Agent, 17) via an AP (Access Point, 15) and FA (Foreign Agent, 16). , 18). In order to use the same SIM (11) in both networks, the HLR (14) and AAAH must be accessible to both the HLR (14) and AAAH (18) to store the database storing the secret key for the SIM (11). Interlocking between the 18 is required, for this purpose various interlocking methods are possible.

In a wireless communication system supporting a mobile IP (eg, 3G packet network), there are two Internet access gateways that can assign an IP address to a mobile terminal. One is a packet data service node (PDSN) (or a foreign agent (FA)), and the other is a home agent (HA). The FA assigns an IP address to a mobile terminal requesting a simple IP service, and the HA assigns an IP address to a terminal requesting a mobile IP service. The IP address assigned by the FA is deleted when the service is terminated, but the IP address assigned by the HA is invariably used unless the mobile terminal moves to another HA area.

Packet communication systems supporting dynamic IP services are configured based on domains and connected to each other through the Internet. Each IP support domain consists of a mobile communication system and other network elements for packet call services. Here, the mobile communication system includes a digital cellular network, a PCS network, a base transceiver system (BTS) constituting an IMT-2000 (CDMA2000 or UMTS) network, which is a next-generation mobile communication network, and It includes a base station controller (BSC). Also, network elements for packet call service include home agent (HA), packet data service node (PDSN), authentication and billing server (Authentication, Authorization & Accounting Server) to support dynamic IP service. AAA, or Radius Server), Domain Name System (DHCP) Server, and Dynamic Host Configuration Protocol (DHCP) Server.

The mobile terminal accesses the packet data service node through a wireless channel. The packet data service node and the home agent assign an IP address to the mobile terminal for which the packet call service is desired. At this time, the IP address assigned by the packet data service node will change every time the mobile terminal moves to the area of another packet data service node, but the IP address assigned by the home agent is fixed in the corresponding domain.

The AAA server performs the authentication and authority verification function and the charging function of the wireless communication network subscriber. Here, a secure channel is formed between the AAA servers. In addition, AAA server is used to identify subscribers using NAI (Network Access Identifier), and combines NAI (mobile host name, PDSN IP address) with DNS server and dynamically allocates IP address. Includes the ability to perform DNS updates over secure channels between AAAs. In other words, the partner host that wants to communicate with the mobile host does not know the IP address of the mobile host that is dynamically allocated. Therefore, the DNS server must be updated dynamically.

DNS servers are distributed naming systems that map domain names and IP addresses. The DNS server maps fixed domain names to changing IP addresses by dynamically updating the domain name at the request of network elements. A domain name is a textual address used to identify hosts that connect to the Internet. It is easier to remember and more intuitive than an IP address consisting of a simple array of numbers.

2 shows a protocol for mutual authentication between the mobile terminal 10 and the wireless Internet network.

First, the FA 16 connected to the wireless Internet network continuously broadcasts an AA (Agent Advertisement, 20) message to its subnetwork according to the Mobile IP protocol. When the mobile terminal 10 enters the subnetwork of the FA 16, the mobile terminal 10 recognizes the AA (20) message and sends the R_Req (Registration Request, 21) message via the FA 16 to the HA ( To 17). The R_Req 21 message includes a Network Access Identifier (NAI) corresponding to the care-of-address received from the FA 16 and the subscriber ID.

In the embodiment of the present invention, a new type of NAI, that is, temporary NAI (hereinafter referred to as TNAI, 22), is used to reduce the number of message exchanges for authentication, and FIG. 3 is generated in the mobile terminal 10 and the FA (16). ) And a data format of the TNAI included in an R_Req (Registration Request) message transmitted to the HA 17.

The TNAI 22 includes an International Mobile Subscriber Identity (IMSI) 31 and a first random number (hereinafter referred to as RAND1) 32, which is a 128-bit random number generated by the SIM 11 for network authentication, and the subscriber's affiliation. Realm 34 information, which is a domain, is included. The tag 30 is an identifier indicating which of the possible authentication schemes is used, and the separator 33 is a symbol for separating the subscriber ID 31 and the domain information 34.

The method of encoding the TNAI 22 fields is as follows. First, the tag 30 and the separator 33 are encoded, for example, by 1 byte of ASCII code corresponding to 9 and @, respectively, and the IMSI 31 recognizes that each byte is 0 to 9, that is, an ASCII code of 0x30 to 0x39. Encoded as a string of bytes. RAND1 (32) uses a 128-bit random number, and encodes 22 bytes using BASE 64 encoding to generate a readable string, and Realm (34) uses the string corresponding to the domain name as it is.

In FIG. 2, the HA 17 receiving the R_Req 22 message separates the IMSI 31 and the RAND1 32 from the TNAI, and transmits the IMSI 31 and the RAND1 32 to the AAAH 18 as an A_Req 23 message. The AAAH 18 extracts the subscriber information and the secret key Ki from the database using the IMSI 31, generates RES1, RAND2, XRES2, and Kc (231) and sends them as A_Reply 24 to the HA 17. This is again sent to the FA 16 as R_Reply (25). Here, RES1 is information used for authentication of a network in a mobile terminal, and XRES2 is information used for authentication of a subscriber in a FA. The second random number RAND2 42 is a 128-bit random number randomly generated by AAAH 18, and Kc is a 128-bit encryption key generated by concatenating 64-bit encryption keys Kc1 and Kc2 generated from Ki and RAND1, Ki and RAND2, respectively. to be.

4 is a block diagram illustrating the operation of the AAAH 18 which is an authentication server when performing the authentication protocol as described above. The subscriber information and the secret key Ki are extracted from the database 41 using the IMSI 31 received from the HA 17, and the first signal generation section 42 is based on the secret key Ki and RAND1. The 64-bit encryption keys Kc1 and RES1 are generated, and the second signal generation unit 43 generates the 64-bit encryption keys Kc2 and XRES2 based on the secret key Ki and RAND2. Here, RAND2 is a random number generated by the random number generator 45.

In FIG. 2, when the FA 16 receives RES1, RAND2, XRES2, and Kc from the HA 17, the FA 16 stores XRES2 and Kc among them, and includes RES1 and RAND2 in the R_Reply (Registration Reply, 26) message. Transfer to (10). The mobile terminal authenticates the network by the following process.

5 is a block diagram of an apparatus for performing a network authentication process in a mobile terminal when performing an authentication protocol. The SIM 11 included in the mobile terminal 10 receives RES1 and RAND2 from the FA 16, and the first signal generation unit 52 uses authentication information Ki and RAND1 stored in the mobile terminal. The XRES1 is generated 213, and the comparator 54 compares the XRES1 with the RES1 received from the FA 16 and 215 authenticates the network. Here, RAND1 is a random number generated by the random number generator 51. In addition, the first signal generation unit 52 generates a 64-bit encryption key Kc1. The second signal generation section 53 generates subscriber authentication information RES2 and 64-bit encryption key Kc2 from the secret key Ki and RAND2 received from the FA 16. RES2 is sent to FA 16, where 128 bits of cryptographic key Kc are generated by concatenating Kc1 and Kc2 (217).

When all the entities participating in the protocol normally follow the protocol, Kc generated by the AAAH 18 in FIG. 4 and Kc generated by the SIM 11 of the mobile terminal 10 in FIG. The terminal 10 and the FA 16 share the encryption key Kc, so that they can be used for secure communication.

The RES2 generated by the SIM 11 of the mobile terminal 10 is delivered to the FA 16 in an A_Req (Authentication Request, 27) message, and the FA 16 is located inside the RES2 received from the mobile terminal 10. After comparing the stored XRES2 (221) and authenticating the subscriber, if the authentication is successful, a success is included in the A_Reply (Authentication Reply, 28) message and transmitted to the mobile terminal 10.

The overall process shown in FIG. 2 is summarized as follows for each device.

When entering the subnetwork of the gateway, the mobile terminal 10 transmits a network access identifier including the first random number and the subscriber identifier to the gateway, generates an XRES1 using the secret key and the first random number stored therein, and then stores the XRES1. The network is authenticated against the RES1 received from the gateway, and the RES2 is generated from the second random number received from the secret key and the gate A, and then the RES2 is transmitted to the gateway.

The gateways 16 and 17 broadcast the agent advertisement message to its subnetwork, separate the subscriber identifier and the first random number from the network access identifier received from the mobile terminal entering the subnetwork, and transmit it to the authentication server. While storing the XRES2 received from the authentication server, the RES1 and the second random number is transmitted to the mobile terminal, and the subscriber is authenticated by comparing the RES2 received from the mobile terminal with the XRES2 stored therein.

The authentication server 18 extracts the secret key using the received subscriber identifier, generates RES1 based on the secret key and the first random number, generates XRES2 based on the secret key and the second random number, and then generates RES1, the first. 2Random number sends XRES2 to gateway.

In addition, the authentication server 18 generates a first encryption key based on the secret key and the first random number, and generates a second encryption key based on the secret key and the second random number, and then the first and second encryption keys. To generate a third encryption key, transmit it to the gateway, the gateway stores the third encryption key, and the mobile terminal 10 uses the secret key and the first random number stored therein to transmit the fourth encryption key. Generate a fifth encryption key based on the secret key and the second random number, and then join the fourth and fifth encryption keys to generate a sixth encryption key, and generate the third encryption key from the authentication server 18. The encryption key and the sixth encryption key generated by the mobile terminal 10 may share the same value.

According to the embodiment of Figure 2, the message transmitted between the mobile terminal 10 and the FA 16 for mutual authentication of the subscriber and the network is R_Req, in addition to the AA (20) message that the FA 16 is always broadcast periodically (21) / R_Reply (26) and A_Req (27) / A_Reply (28) two pairs of request / response messages.After authentication is completed, the 128-bit encryption key Kc () between the mobile terminal 10 and the FA 16 45) are shared. Therefore, in one embodiment of the present invention, in the wireless Internet network, in addition to the AA message periodically sent by the FA, the mutual authentication of the subscriber and the network is completed by only two pairs of request / response messages between the mobile terminal and the FA, The encryption key generation algorithm can be applied twice to increase the valid key length.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, which are also implemented in the form of a carrier wave (for example, transmission over the Internet). It also includes. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The best embodiments have been disclosed in the drawings and specification above. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, according to the present invention, the subscriber and the network can recognize each other only by two pairs of request / reply messages, and by repeatedly applying the authentication algorithm used in the existing SIM-based mobile communication network without modification. The 128-bit encryption key can be shared for future secure communication. Therefore, it is possible to increase the safety of the wireless Internet network at a minimum cost and to effectively interwork the existing mobile communication network and the wireless Internet network.

The present invention provides a means for providing mutual authentication between a subscriber and a network using a SIM in a wireless Internet network and sharing a key with each other, wherein the subscriber and the network of the wireless Internet request / response messages. Minimizing to two pairs, authentication and key sharing can be completed using the authentication algorithm used in the existing SIM-based mobile communication network.

In addition, an object of the present invention is to provide SIM-based mutual authentication and key sharing in an economical manner in a wireless IP network, and to minimize the added cost for this. The SIM-based subscriber authentication method of the second generation mobile communication network was modified to enable network authentication, and at the same time, the number of valid key bits shared after authentication could be increased to 128 bits to improve safety.

According to the present invention, the subscriber authentication prevents unauthorized users from using the network, and at the same time, authenticates the network and the server itself, thereby preventing the subscriber's personal information from being leaked by the fake server, and more secure communication due to the longer key. to provide.

Claims (9)

In the authentication method in which the mobile terminal is connected to the wireless Internet via a gateway, A gateway connected to a wireless Internet network, broadcasting an agent advertisement message to its subnetwork; When a mobile terminal enters the subnetwork, transmitting a network access identifier including a first random number and a subscriber identifier to the gateway; The gateway separating the subscriber identifier and the first random number and transmitting the same to the authentication server; The authentication server extracts a secret key using the subscriber identifier, generates RES1 based on the secret key and the first random number, and generates XRES2 based on the secret key and the second random number; The authentication server transmits the RES1, the second random number, and the XRES2 to the gateway; The gateway storing XRES2 and transmitting the RES1 and the second random number to the mobile terminal; Generating a XRES1 using a secret key and a first random number stored in the mobile terminal, and then comparing the XRES1 with the RES1 received from the gateway to authenticate the network; Generating a RES2 from the secret key and the second random number received from the gateway, and then transmitting the RES2 to the gateway; And And comparing the RES2 received from the mobile terminal with the XRES2 stored therein to authenticate the subscriber. The method of claim 1, The authentication server generates a first encryption key based on the secret key and the first random number, generates a second encryption key based on the secret key and the second random number, and then joins the first and second encryption keys to form a third encryption key. Generating an encryption key and transmitting it to the gateway, the gateway storing the third encryption key; And The mobile terminal generates a fourth encryption key using the secret key and the first random number stored therein, generates a fifth encryption key based on the secret key and the second random number, and then concatenates the fourth and fifth encryption keys. Generating a sixth encryption key by further comprising: And a third encryption key generated by the authentication server and a sixth encryption key generated by the mobile terminal share the same value. The method of claim 1, The network access identifier generated in the mobile terminal and transmitted to the gateway includes a subscriber identifier, a first random number generated for network authentication, and domain information of the subscriber. When entering the gateway's subnetwork, the network access identifier including the first random number and the subscriber identifier is transmitted to the gateway, the XRES1 is generated using the secret key and the first random number stored therein, and the XRES1 is received from the gateway. Comparing and authenticating the network, generating a RES2 from the second random number received from the secret key and the gateway, and then transmitting the RES2 to the gateway; Broadcasts the agent advertisement message to its subnetwork, separates the subscriber identifier and the first random number from the network access identifier received from the mobile terminal entering its subnetwork, sends it to the authentication server, and receives the XRES2 received from the authentication server. A gateway for transmitting the RES1 and the second random number to the mobile terminal, and comparing the RES2 received from the mobile terminal with the XRES2 stored therein to authenticate the subscriber; And Extract the secret key using the subscriber identifier, generate RES1 based on the secret key and the first random number, generate XRES2 based on the secret key and the second random number, and then gateway RES1, the second random number, and XRES2. Wireless Internet subscriber authentication device comprising an authentication server for transmitting to. The method of claim 4, wherein The authentication server generates a first encryption key based on the secret key and the first random number, generates a second encryption key based on the secret key and the second random number, and then joins the first and second encryption keys to form a third encryption key. Generate an encryption key, send it to the gateway, the gateway stores the third encryption key, The mobile terminal generates a fourth encryption key using the secret key and the first random number stored therein, generates a fifth encryption key based on the secret key and the second random number, and then concatenates the fourth and fifth encryption keys. To generate the sixth encryption key, And a third encryption key generated by the authentication server and a sixth encryption key generated by the mobile terminal share the same value. A secret key extracting unit for extracting a secret key using the received user identifier; A first signal generator for generating RES1, which is information used for authentication of a network in a first encryption key and a mobile terminal, based on the secret key and the received first random number; Random number generation unit for generating a second random number; A second signal generator for generating XRES2, which is information used for authentication of a second encryption key and a subscriber, based on the secret key and the second random number; And And an encryption key generation unit for generating a third encryption key by joining the first encryption key and the second encryption key. In the apparatus for receiving the RES1 and the second random number to perform a network authentication process in the mobile terminal, Random number generation unit for generating a first random number; A first signal generator for generating XRES1 and a first encryption key, which are network authentication information, from a secret key stored therein and the first random number; A comparison unit for authenticating a network by comparing the XRES1 with the received RES1; A second signal generator for generating subscriber authentication information RES2 and a second encryption key from the secret key and the received second random number; And And an encryption key generation unit for generating a third encryption key by joining the first encryption key and the second encryption key. A foreign agent (FA) connected to a wireless Internet network continuously broadcasting an authentication and authorization (AA) message to its subnetwork according to a mobile IP protocol; When the mobile terminal enters the subnetwork of the foreign agent, the mobile terminal recognizes an authentication and authorization (AA) message and sets the network access identifier including the first random number and the subscriber identifier to the foreign agent and the HA. Transmitting to a home agent; The home agent (HA) separates the subscriber identifier and the first random number, and transmits the same to the authentication, authorization & accounting server in home side (AAAH); Authentication, Authorization & Accounting server in Home side (AAAH) extracts a secret key using the subscriber identifier, generates a first encryption key and RES1 based on the secret key and the first random number, and generates the secret key and the second random number. Generating a second encryption key and an XRES2 based on the second encryption key; and concatenating the first and second encryption keys to generate a third encryption key; Authentication, Authorization & Accounting server in Home side (AAAH) is the step of transmitting the RES1, the second random number, XRES2, the third encryption key to the HA (Home Agent) and FA (Foreign Agent); The foreign agent (FA) stores the XRES2 and the third encryption key and transmits the RES1 and the second random number to the mobile terminal; Generating a XRES1 and a fourth encryption key using a secret key and a first random number stored therein, and then authenticating the network by comparing the XRES1 with a RES1 received from a foreign agent (FA); The mobile terminal generates the RES2 and the fifth encryption key from the secret key and the second random number received from the foreign agent (FA), and then sends the RES2 to the foreign agent (FA), and concatenates the fourth and fifth encryption keys. Generating a sixth encryption key; And FA (Foreign Agent) is a step of authenticating the subscriber by comparing the RES2 received from the mobile terminal and the XRES2 stored therein; wireless Internet subscriber authentication method comprising a. The method of claim 8, And a third encryption key generated by the authentication server and a sixth encryption key generated by the mobile terminal share the same value.

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