Method of and system for extending the wispr authentication procedure

METHOD OF AND SYSTEM FOR EXTENDING THE

WISPr AUTHENTICATION PROCEDURE

Related application

This application claims priority under 35 U.S.C. § 119(e) of the co-pending provisional patent application serial number 61/415,734, filed November 19, 2010, and titled, "Method, System, and Client Software for Extending WISPr Authentication Procedure," which is hereby incorporated by reference. Field of the Invention

The present invention relates to network-access authentication for roaming into or otherwise accessing wireless telecommunications networks. More specifically, the present invention relates to authenticating users roaming into or accessing Wi-Fi/WiMAX networks using the user credential of a GSM/CDMA/LTE network.

Background of the Invention

Currently, Wi-Fi hotspots are deployed globally by various Wireless Internet Service Providers (WISPs). Electronic devices with Wi-Fi chipsets and capabilities are able to connect to these Wi-Fi hotspots to access data networks, such as the Internet. These devices include, but are not limited to, personal laptops, mobile handsets, televisions, digital cameras, and DVD players. Normally these hotspots require the users to be authenticated and authorized before accessing their network services. The users must supply their own credentials for the Wi-Fi networks to authenticate against the users' home service providers. A typical credential that is widely used in current public hotspot is a username and password combination.

For mobile networks, user credentials are issued as Subscriber Identity Module (SIM) for

Global System for Mobile Communications (GSM) networks. A SIM card securely stores a secret authentication key (Ki) identifying a mobile phone service subscriber, as well as subscription information, preferences, and other information. The SIM card also securely stores A3 and A8 programmable algorithms, the same logic as the A3/A8 algorithm stored in the mobile network's Home Location Register (HLR). The SIM card also stores the International Mobile Subscriber Identity (IMSI), which is used to uniquely identify the mobile phone service subscriber. When the SIM card is manufactured, the IMSI is paired with an authentication key Ki, a 128-bit number used for authentication and cipher key generation. The Ki is stored only on the SIM card and at the HLR and is never transmitted across the network, on any link.

The SIM card has corresponding components in different mobile networks. For example, the corresponding component in Universal Mobile Telecommunications System (UMTS) networks is the Universal SIM (USIM) card. The corresponding component in Code Division Multiple Access (CDMA) networks is the Removable User Identity Module (R-UIM) card.

The user credential, as a SIM card, is needed in the smartphone to complete the authentication and service registration procedure in mobile networks. Utilizing the existing user credential for the authentication, authorization, and accounting (AAA) in Wi-Fi/WiMAX networks is a challenge for seamless roaming when offloading mobile data to Wi-Fi/WiMAX networks.

IEEE specification 802. IX defines the encapsulation of the Extensible Authentication

Protocol (EAP) over IEEE 802 LAN/WLAN which is known as "EAP over LAN," or EAPOL. The standard formats and procedures to implement SIM-based authentication protocol

(Extensible Authentication Protocol (EAP) Method for GSM Subscriber Identity Module, or EAP-SIM, for authentication and session key distribution using the SIM from the GSM) is defined in Internet Engineering Task Force (IETF) Request for Comments (RFC) 4186. IETF RFC 4187 defines the EAP method for UMTS Authentication and Key Agreement (EAP-AKA) authentication.

The 802. IX protocol operates on top of the Network Link Layer, which introduces a high entry barrier for such solutions to be widely adopted by the Wi-Fi hotspots. The protocol requests support from the network side, which requires major changes to the network infrastructure. It also requires support from the client side, which imposes significant demands for the end user's electronics capability enhancement to support 802. IX, and also introduce complex settings that are not easy for normal users to correctly configure. Thus, currently, only a few Wi-Fi hotspots are able to support 802. IX.

Produced in February 2003 and chartered by the Wi-Fi Alliance, "Wireless ISP roaming (WISPr) 1.0" (hereinafter, the "WISPR 1.0 document") is considered the defacto best practices document for implementing roaming between Wi-Fi service providers. Most commercial Wi-Fi networks have been able to support WISPr 1.0, and accordingly, those networks are able to support the Universal Access Method (UAM) protocol that is defined in Appendix D of the WISPr 1.0 document. The WISPr 1.0 document is herein incorporated by reference in its entirety.

UAM authentication for accessing a wireless network is based on the concept of a

"walled garden." A walled garden is a "reversed" intranet that prevents a device connected within the walled garden from accessing the Internet prior to being authenticated. This technique, unlike 802. IX, allows the device to bring up all networking layers, including layer 3 (i.e., the IP layer) prior to being authenticated and charged for the session. An Authentication System in the walled garden can be used to perform different types of authentication, including authentication via browser and payment by credit card (not possible with 802. IX). The wireless network operator can also define special policies to allow the end user to access designated

Authentication Systems that are not sitting within the walled garden.

But the UAM protocol defined in WISPr 1 .0 has known limitations with regard to supporting various authentication protocols. It is not designed to support EAP protocols, and thus cannot be used to support SIM, USIM, and various credentials for Wi-Fi access authentication.

Summary of the Invention

In accordance with embodiments of the invention, an Authentication System is implemented between a Wireless Internet Service Provider network and a Mobile Network. A SIM card is used as the user credential to be authenticated by the Authentication System against the Mobile Network Authentication Server. The Authentication Server in a GSM network can be the HLR, while in a 3G/4G network, it is the Home Subscriber Server ("HSS"). The Authentication System utilizes the HTTP/S protocol to communicate with the client (e.g., software) running on the user devices, which in turn challenges the SIM card inserted into the device and receives the challenge response from the SIM card. The Authentication System verifies the challenge result against the result returned from a Mobile Network Authentication Server. If the two results match, the Authentication System returns a separate credential to the client software, which can then be used by the client to login to the Wi-Fi network using the WISPr 1.0 protocol.

In one embodiment, the Authentication System must be reached by the client software before it is successfully authenticated and granted a permanent Internet connection. Thus a common variant of one embodiment is that the Authentication System is implemented in the WISP's walled garden environment, which can then be reached by the client without any authentication in advance.

If the Authentication System must be implemented outside the walled garden environment, embodiments of the invention grant the end user a temporary Internet connection. The client can utilize this connection to get authenticated with the Authentication Gateway. After a successful authentication, the client tears down the temporary Internet connection and utilizes a new credential to get a permanent Internet connection.

In one embodiment, the authorization result for accessing a Wi-Fi network is a one-time username and password combination granted by the remote Authentication System. The client uses the one-time username and password to login to the Wi-Fi network using, for example, the Wireless Internet Service Provider Roaming version 1.0 (WISPr 1.0) login procedure.

Brief Description of the Drawings

Figure 1 shows an electronic device accessing a mobile network, using a wireless network and a wide area network, in accordance with one embodiment of the present invention.

Figure 2 illustrates a call flow between client software and the Authentication System within a Wi-Fi network's walled garden, in accordance with one embodiment of the present invention. Figure 3 shows the steps of a method of accessing a Wi-Fi network using components outside the Wi-Fi network's walled garden, in accordance with one embodiment of the present invention.

Figure 4 illustrates a call flow between client software and an Authentication System for non-white listed Wi-Fi networks, outside the walled garden, in accordance with one embodiment of the invention.

Detailed Description of the Invention

In accordance with the embodiments of the invention, the authentication process in wireless networks is facilitated by introducing new components to the network side, including a public Internet-accessible Authentication Gateway and an Account Databases that hosts temporary user account information. The Authentication System can include multiple modules that support multiple functions, which can include interfacing with smart clients using the HTTP/S protocol and converting HTTP/S messages into SS7/MAP protocols to get challenge vectors from the mobile network authentication server. In one embodiment, a Mobile

Application Part (MAP) Gateway converts between AAA and SS7/MAP protocol for Extensible Authentication Protocol- SIM/Authentication and Key Agreement (EAP-SIM/AKA)

authentication.

Other embodiments include enhanced smart clients installed in a user's client equipment, such as personal laptops, mobile handsets, televisions, digital cameras, and other consumer electronics equipped with Wi-Fi access availability.

FIG. 1 shows an exemplary Wi-Fi environment that includes 3 different networks, 110, 115, and 120. The Visited Wireless Network 110 provides the local Wi-Fi access service to the end users. The network 110 includes various Hotspot Access Points 111 for the end users to connect with, an Access Gateway 112, and an AAA Proxy 113 to validate the end user's credential against the end user's home Authentication System. The Wide Area Network 115, which can be accessed by the end user via an Internet connection, includes an Authentication System 116 (comprising a Web server), an AAA Proxy 117, an Account Database 118, and a MAP Gateway 119. The Mobile Network 120 is the Home Service Provider that issues the SIM card to the end user and includes an HLR 121 as the authentication server for the SIM card (e.g., 102 in device 100).

The user device 100 comprises a client 101 (e.g., software), a SIM card 102, a TCP/IP protocol stack 103, a GSM module 104, and a Wi-Fi module 105. The GSM module 104 uses the SIM card 102, which is issued by the Home Mobile Network 120, and is used as the

authentication credential against the HLR 121. The Wi-Fi module 105 provides the Wi-Fi signaling detection, registration and connection with the Visited Wireless Network 110.

In some embodiments the, Hotspot Access Points 111 allow the end user devices to connect to the Wi-Fi network using IEEE 802.11 a/b/n/g standards. The Access Gateway 112 implements the WISPr protocol, firewall control, and an AAA client that generates

authentication requests on behalf of the end user. The AAA Proxy 113 interconnects with the AAA Proxy (e.g., 117) in an Intermediary Network (e.g., 115) or Home Network. The public Wi-Fi network can also include Monitoring tools, Billing and operation systems, and other components that are not relevant to this invention and thus that are not described in detail here.

The relevant components vary according to the home network type. For a

WiMAX/CDMA Home Network, the relevant components include the AAA server that hosts the user account. For a GSM/WCDMA Home Network, the relevant components include the HLR system. Those skilled in the art will recognize corresponding components in other networks.

Figure 2 illustrates the steps 200 of a flow diagram of an exemplary process for providing

SIM-based authentication between a client (e.g., 101 in Figure 1) and systems for those white listed Wi-Fi networks. As in all the figures, identical labels refer to the same element or step. As used herein, a "white listed" Wi-Fi network is one in which its firewall is open to allow user devices to access a known URL known before these devices are authenticated. In contrast, non- white listed Wi-Fi networks have firewalls that are not open to this URL. As such, "whitelisted" refers to networks inside a walled garden, and "non-whitelisted" refers to networks outside the walled garden. When the end user's digital device enters into range of a public Wi-Fi network, the device scans for the WLAN network and then connects to the network. For SIM-based authentication, the digital device is equipped with a SIM card as the device credential.

Before the device credential is authenticated, the device is able to access the specified Authentication System that has been implemented in the Wi-Fi network walled garden. Thus, in the step 201, the client 101 on the device 100 retrieves the IMSI information from the SIM card 102, generates an HTTP/S request containing the IMSI information, and sends the request to the Authentication System (also referred to as Web Server) 116. In the step 202, the Web Server 116 sends a Request Authentication (including the IMSI) to the MAP Gateway 119. In the step 203, the MAP Gateway 119 then fetches the IMSI information for the request and generates an SS7 mobile application part (MAP) Send- Authentication to the HLR 121 in the Home Network to get the challenge vector from the home HLR 121.

As a standard procedure, in the step 204, the HLR 121 then generates RAND for this request, calculates the corresponding SRes according to the A3 algorithm, including the triplet (IMSI, RAND, SRes), and transmits this to the MAP Gateway 119 in the MAP Response. In the step 205, the MAP Gateway 119 transmits the triplet to the Web Server 116, which stores the triplet in a local database and, in the step 206, transmits to the client 101 an HTTP/S response containing a RAND value as the challenge.

On receiving the HTTP/S response, in the step 207, the client 101 inputs the RAND value to the SIM card 102 and retrieves the SRes' result from the SIM card 102. The SRes' result is calculated based on the RAND value and the embedded A3 algorithm in the SIM card 102. Then, in the step 207, the client 101 generates another HTTP/S request containing the SRes' and transmits it to the Web Server 116. The Web Server 116 then compares the SRes' received from the client 101 against the SRes that it stores after receipt from the Home HLR 121. If the SRes' and the SRes do not match, then in the step 208a, the Web Server 116 returns a Failure message in the HTTP/S response, thus preventing the client 101 from continuing the authentication procedure and denying it access to the Wi-Fi network. On the other hand, if the SRes' and the SRes do match, in the step 208b, the Web Server 116 generates a credential for the client 101, stores the credential in the Account Database 118, and, in the step 209, returns to the client 101 a success message with the newly generated credential in the HTTP/S response message.

On receiving the success message, the client 101 is able to follow the standard WISPr 1 .0 procedure to pass the Wi-Fi network authentication procedure, by using the credential information in the format of username, password and realm information. The procedure from step 210 to step 219 closely follows the procedure described in the document "Wireless ISP roaming (WISPr) 1.0", Appendix D of a "Smart Client to Access Gateway Protocol," incorporated by reference above. For example, in the step 210, the client 101 communicates with the Access Gateway 112 using the WISPr login procedure. In the step 211, the Access Gateway 112 issues an access request to the AAA Proxy 113. In the step 212, the AAA Proxy 113 issues an access request to the AAA Proxy 117. In the step 213, the AAA Proxy 118 performs an authentication against a database in the Account Database 118. In the step 214, the AAA Proxy 117 transmits an access accept message to the AAA Proxy 113, and in the step 215, the AAA Proxy 113 transmits an access accept message to the Access Gateway 112. In the step 216, the Access Gateway 112 completes the login procedure with the client 101. Concurrently with or soon after the step 215, the AAA Proxy 113 issues a Start Accounting request to the AAA Proxy 117, which responds with an Accounting Response in the step 218. Finally, in the step 219, the client 101 is allowed to access the Internet. In this embodiment, the authentication is conducted by the Authentication System 116 against the Account Database 118, which stores the credentials. Thus, the end user's device can successfully pass the authentication procedure as long as the client correctly utilizes the credential information generated by the Authentication System 116.

The client 101 and the Intermediary Network 115 can communicate using protocols that include, but are not limited to, HTTP, HTTPS, and Session Initiation Protocol (SIP). The AAA Proxy 113 can communicate with other components using Remote Authentication Dial in User Service (RADIUS), its replacement (DIAMETER), or other protocols.

Figure 3 illustrates the steps 300 of a method for accessing a Wi-Fi network using an Authentication System outside the Wi-Fi network's walled garden in accordance with one embodiment of the invention. For Wi-Fi networks that cannot implement the Authentication System in its walled garden, the client is not able to access the Authentication System before it is authenticated. Thus, this embodiment provides a way to temporarily allow the client to be authenticated.

Credential matching rules and algorithms can be preconfigured between the client software and the Authentication Gateway. Thus, in the step 301, the end user device enters a Wi- Fi network, the client detects that the Authentication System is not in the walled garden list of this Wi-Fi network. To detect that the wireless network does not include the Authentication System in the walled garden list, the client software uses a database or configuration file, which keeps a record of whether the network includes the Authentication System or not. Those skilled in the art will recognize that a service set identifier (SSID) can be used as the network identifier of the Wi-Fi network. In another embodiment, the client is triggered to connect to the

Authentication Gateway, and if the network connection is rejected or redirected, then the Authentication System can be assumed to be outside of the walled garden list.

Next, in the step 302, the client starts the WISPr login with credentials using a predefined algorithm. In one embodiment, the predefined algorithm includes using special realm

information plus special password generation rule. Thus, in the step 303, once the Authentication System receives the request from the Wi-Fi network via the WISPr login procedure, the

Authentication System validates the request against the credential algorithms and acknowledges the login request by granting temporary Internet access. As one example, the temporary Internet access includes allowing timed use, such as between 1 and 5 minutes, and optionally rejecting repeated retries within short periods to avoid misuse.

In the step 304, the client is able to access the Internet, which can initiate the real authentication with Authentication System via the temporary connection. The steps 304 and 305 are exactly the same as the steps 201 to 209, described in Figure 2. The Authentication System issues another temporary credential to the client once it successfully authenticates the SIM card against the Home HLR. Starting from step 306, the client can automatically hang up the temporarily connection that is initiated in the step 302, using the standard WISPr logoff procedure with the first WISPr session information. In the step 307, the client re-initiates the second WISPr login procedure using the new credential received in the step 305. In the step 308, then the Authentication System is able to allow the client to login to the Wi-Fi network with a permanent network connection once it successfully verifies the credential it stores in the Account Database and the one it receives from the Wi-Fi network.

Figure 4 illustrates a call flow diagram of the steps 400 of an exemplary process for providing SIM based authentication between a client and systems for non-white listed Wi-Fi networks (e.g., outside the walled garden), in accordance with one embodiment of the invention. For the non-white listed Wi-Fi networks, the client is not able to access a Web Server before it is authenticated. The embodiment shown in Figure 4 provides a way to temporarily allow the client to be authenticated.

From the step 401 to the step 411, the client closely follows the procedure described in the previously incorporated "Wireless ISP roaming (WISPr) 1.0," Appendix D of a "Smart

Client to Access Gateway Protocol." During this procedure, the client uses a special predefined username, password and second realm information. The username is in the form of the IMSI that is retrieved from the SIM card, and the password is randomly generated by the client. In this embodiment, the second special realm is different from the previous first realm, and is predefined and recognizable in the Intermediary Network AAA Proxy. Special policies are configured in the Intermediary Network AAA Proxy for this second realm and include: ignore the password and always return success for all authentication requests against this realm; always return authorization with limited Internet access duration (e.g., one to five minutes); reject repeated retries within short periods of time to avoid misuse; etc. With such policies, the Intermediary Network AAA Proxy returns Access-Accept to the Visited Wi-Fi Network AAA Proxy. Thus the Visited Network Access Gateway allows the device to access the Internet for a limited period of time. Accordingly, in the step 411, the client is able to access the Internet. Once the Internet is accessible, the client is able to get in touch with the Web Server, and another authentication procedure is initiated between the client and the Web Server. The procedure from the step 412 to the step 420 is exactly the same procedure as the step 201 to the step 209 as shown in Figure 2, and accordingly these steps are not described in detail here.

On receiving the HTTP/S success response message with a one-time password included in the step 420, the client knows that it is successfully authenticated with the actual credential. But since the client software has been granted temporary Internet access using a dummy password in the first WISPr login procedure, the client needs to shutdown the temporary Internet access and re-establish a new Internet access with the new password. Thus from the step 430 to the step 432, the client follows the WISPr logoff procedure to disconnect the temporary Internet access. From the step 440 to the step 449, the client follows the WISPr login procedure to be authenticated with a new username and the one-time password, and then re-establishes a totally new Internet access. This login procedure is exactly the same as the steps 210 to 219 in Figure 2.

It will be appreciated that the steps 300 and the calls 200 and 400 are merely illustrative. In other embodiments, some of the steps or calls are deleted, others are added, and the order of the steps or calls is changed.

It will also be appreciated that in different embodiments, some or all of the components shown in Figure 1 include a memory storing computer-executable instructions for executing one or more of the corresponding steps 300 or calls 200 and 400 and a processor for executing those corresponding steps or calls. In other embodiments, the components contain application specific integrated circuits or similarly functioning components for executing the steps or calls.

While the embodiments described above use the WIPr 1.0 protocol, it will be appreciated that other versions of WISPr, as well as different protocols, can also be used.

The present invention has been described above with reference to exemplary

embodiments. It will be apparent to those skilled in the art that various modifications may be made to the embodiments without departing from the spirit and scope of the invention as defined by the appended claims.