Abstract:
A system and method for distributed authentication service is disclosed, which prevents any single participant from monitoring the logon rates of other participants is disclosed. In particular, there is no single central list that is consulted to identify where the authentication should be performed. Rather, the systems keys on the domain portion of the global user ID. The client portion parses the entered ID and re-directs the submission to the appropriate authentication service. Rather than consulting a global look-up table, the domain name is pre-pended to a central host domain and DNS is consulted to find the location of the underlying authentication servers. The DNS look-up is distributed and cached and, as a result, the look-up cannot be centrally monitored.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates generally to Internet based authentication technology. More particularly, the invention relates to a system and method for distributed authentication service. 
     2. Description of the Prior Art 
     The explosive growth of the Internet is changing the ways in which we communicate, conduct business, and pursue entertainment. A few years ago, electronic commerce (E-commerce) was just an interesting concept. By 1999, however, it had become the hottest thing around. Today, not only are consumers buying an enormous volume of goods or services over the Internet, but the business-to-business E-commerce has taken off as well. 
     The basic cell of E-commerce is an electronic transaction, which requires a buyer or user fills out one or more electronic forms on screen and click a button named “send”, “buy” or “submit”, etc. To complete such an electronic transaction, a user has to go through an authentication process. In other words, the user must provide the seller or service provider with some information such as his or her personal identification, contact information, or even financial information. The authentication process may take from several minutes to hours. Because each seller or service provider maintains its own authentication server and database, millions of seller and service providers might share thousands of millions of consumers or users. Some of the consumers or users might be required to go through the same or similar authentication process again and again if they have transactions with many sellers or service providers. This repetitive authentication not only wastes consumers&#39; precious time, but also burdens the sellers or service providers because they have to expand their databases to keep detailed authentication information for a growling number of users. This situation brings forth a technical need to create a universal, unified single-logon infrastructure wherein a specific user may be authenticated once for all and the authentication result is widely recognized by a large number of sellers or service providers. 
     In responding to that need, several approaches have been developed. For example, Microsoft Corporation has introduced a “.NET Passport” single sign-in system. With “.NET Passport”, a user doesn&#39;t need to register a member name and password at each new site he visits. The user may simply use his e-mail address and password that registered as his “.NET Passport” to sign in to any participating site or service. The information the user registers with “.NET Passport” is stored online, securely, in the “.NET Passport” database as the user&#39;s “.NET Passport profile.” When the user signs in to a “.NET Passport” participating site by typing his e-mail address and password in the “.NET Passport” sign-in box, “.NET Passport” confirms that (1) the e-mail address he typed is registered with “.NET Passport”, and (2) the password he typed is correct. “.NET Passport” then notifies the site that the user has provided valid “sign-in credentials”, and he is given access to the participating site. Once the user signs in to one “.NET Passport” participating site during an Internet session, he can sign in to others simply by clicking the “.NET Passport” sign-in button on each site. 
     Another example is America Online Inc.&#39;s “Screen Name Service” system, which provides free service allowing anyone with a “Screen Name” to register easily and securely at a variety of Web sites. The “Screen Name Service” eliminates a user&#39;s need to remember multiple names and passwords for all the places he visits on the Web. With the “Screen Name Service” system, each user has a “My Profile”, which stores the user&#39;s personal information used to make registering at sites across the Web simple and secure. When the user registers at a participating Web site using the service, he has the opportunity to choose which fields of information stored by AOL, if any, he would like to share with that site. No information is shared with any Web site without the user&#39;s explicit permission. When the user agrees to share certain information with a participating site, that information is conveyed to the Web site at which he is registering. Another feature is that the user is provided with a “My Site List”, which is an effective way to manage personal information because it shows the user with which sites he has registered with using the service. The user can view the privacy policy of a site to see how it uses information it knows about the user. The user can also decide if he would like to be signed into the site without being prompted and if the site should be updated with information if “My Profile” changes. 
     The common characteristic of these approaches is that they implement a centralized solution for authentication and authentication information management. Undoubtedly, the centralized solution may overcome the repetitive authentication and repetitive storage problems that exist in the scattered, disorganized situation. 
     However, the centralized solution has three major disadvantages. First, in a centralized authentication system, because all the login requests go to a central authentication server, the traffic to the server could be very heavy, the requirements for the process capability and database size could be predictably high, and the authentication process would be very slow when the number of requests is overwhelmed for the server. Second, in case that the central authentication system fails, all the authentication requests would be suspended. Third, the central authentication service provider could monitor the participating sites&#39; logon rates and a site which hosts a user&#39;s login page could monitor the user&#39;s logon information. 
     What is desired is a solution to have each authentication carried out at one of participating servers and have the authentication result distributed and cached all over the network of the participating servers so that the authentication results cannot be centrally monitored. 
     SUMMARY OF INVENTION 
     The invention herein comprises a system and method for providing a distributed authentication service. According to the invention, the user names are chosen from a fairly universal name space, e.g., communication addresses, and yet the servicing of the authentication, e.g., password checking, is distributed among the participants of an authentication federation that the system supports. Typically, the participants are commercial servers that can host authentication. A key goal of this distributed system is to prevent any single participant from monitoring the logon rates of other participants. Most critically, there is no single central list that is consulted to identify where the authentication should be carried out. 
     In the preferred embodiment, the system keys on the domain portion of the global user identification (GUID), which is typically an email address formatted ID. The client portion of the system, typically implemented as JavaScript function in a browser, parses the entered GUID, and redirects the submission to the appropriate authentication server. Rather than consulting a global lookup table, the domain portion of the GUID is pre-pended to a central host domain, i.e., the distributed authentication system&#39;s domain, and the domain name system (DNS) is consulted to find location of the underlying authentication servers. A critical point is that the DNS lookup is distributed and cached, and as a result, the lookups cannot be centrally monitored. 
     The system may further comprise an authentication server as a default server. The DNS resolver in the central location can automatically map all unrecognized domains into the default server. The end result is that substantially all possible GUID&#39;s are automatically distributed to the appropriate authentication servers. 
     Note that in a browser scenario, the scanning and translating are performed by simple standard JavaScript, and the submission can be automatically sent to the appropriate authentication server without the party that hosted the login page being allowed to see any of the information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a block diagram illustrating a network  100  that facilitates distributed authentication service; 
         FIG. 1B  is a schematic diagram illustrating an exemplary domain name system (DNS)  200  incorporated in a global network; 
         FIG. 1C  is a table diagram illustrating an IP address database associated with the domain name server DNS  06  in the network  100 ; 
         FIG. 2  is a flow diagram illustrating a process  220  for providing distributed authentication service according to one preferred embodiment of the invention; 
         FIG. 3  is a flow diagram illustrating a process  230  for providing distributed authentication service according to another preferred embodiment of the invention; 
         FIG. 4  is a flow diagram illustrating a process  240  for providing distributed authentication service according to another preferred embodiment of the invention; and 
         FIG. 5  is a flow diagram illustrating a process  250  for providing distributed authentication service according to another preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  is a block diagram illustrating an exemplary network  100 , named Magic Carpet Network (MCN), which provides distributed authentication service among a global authentication federation. The MCN network includes a number of clients, e.g., client device  101 , and a number of authentication servers, e.g., servers  111 ˜ 113 , which are communicatively connected via the Internet  105 . Each authentication server represents a participant of the global authentication federation and has a database, e.g., DB  01 ˜DB  03 , which caches its registered users&#39; identification information and any authentication token from other participating authentication servers. Each client or authentication server can access a local domain name server, which is one of many domain name server&#39;s coupled in a domain name system (DNS). 
       FIG. 1B  is a schematic diagram illustrating an exemplary domain name system  200  incorporated in a global network. A domain name system (DNS) is a general-purpose, replicated, distributed data query service for looking up host Internet Protocol (IP) addresses based on host names. It is hierarchical, consisting of domains, sub-domains, sites, and hosts. Unique names are formed from smallest to largest, and are of the form user@host.site.subdomain.domain, where host and site are often optional. On the Internet, domain names typically end with a suffix denoting the type of site. For example, “.COM” for commercial sites and “.ORG” for organizations. A name resolution client, such as the client  101  in  FIG. 1A , can be configured to search for host information in the following order: first in the local/etc/hosts file, second in network information service (NIS), and third in DNS. This sequencing of naming services is sometimes called name service switching. DNS can be queried interactively using command nslookup. 
     The MCN network  100  illustrated in  FIG. 1A  is registered under a unique domain name, for example MCN.ORG, in the central location of the DNS  200 . The MCN network  100  requires each participant to register its authentication server as an individual machine under the MCN domain. In other words, the hostnames of the authentication servers share a common suffix. For example, AOL, as a participant host, registers its authentication server as AOL.COM.MCN.ORG under the unique domain MCN.ORG. The domain name server DNS  06  associated with the MCN network  100  just treats each participant authentication server as a host machine. For example, it treats AOL.COM.MCN.ORG as the host name of AOL Authentication Server  101 . 
     As illustrated in  FIG. 1C , the database DB  16  associated with the domain name server DNS  06  maintains a list of fully qualified domain names (FQDN) for the registered authentication servers. A FQDN consists of its local hostname and its domain name, including a top-level domain. For example, AOL.COM.MCN.ORG is a FQDN, in which AOL.COM is a host name, MCN.ORG is a domain name, and .COM is a top level domain name. Each of FQDN has a unique Internet Protocol (IP) address, which was installed in the database DB  06  when a commercial participant of the federation registered its authentication server under the domain MCN.ORG. 
     Client device  101  is empowered with an interface that enables a user to interact with a distributed authentication system embodied in the MCN network  100 . In the preferred embodiment, the client device  101  includes a browser  103  which displays HTML file. The HTML facilitates a number of functions, including the authentication function, which is typically implemented in JavaScript. Alternatively, the client device  101  may include an application specifically for managing the authentication process. 
     To initiate an authentication process, a user must log in the distributed authentication system by entering his global user identification (GUID) and password and clicking a login button. A GUID is in a universal name space format, for example, an email address format. Thus any given GUID consists of two portions separated by a delimitation symbol, such as @. The first portion is the user&#39;s user name, and the second portion is a domain name indicating the domain of a server (such as AOL.COM) with which the user registered. For example, an AOL registered user with a user name, joe, should enter his GUID joe@AOL.COM and his password secret911 for authentication by AOL Authentication Server  111 , which is registered as AOL.COM.MCN.ORG under the domain MCN.ORG. 
     Referring to  FIG. 1B , assuming the user enters his GUID and password from a page  201  hosted by ZYX.COM. Once the user gets logged in, the client portion of the authentication system, parses the user&#39;s GUID joe@AOL.COM and extracts the domain portion AOL.COM from the GUID. Then, it appends the MCN domain name as a suffix to the domain portion. As a result, a FQDN AOL.COM.MCN.ORG is formed. 
     The client portion of the authentication system first looks up a local domain name server DNS  05  to find location of the authentication server with a FQDN AOL.COM.MCN.ORG. After if fails in DNS  05 , it populates the lookup request to its upper level DNS  02 ; after it fails in DNS  02 , it populates the lookup request to the top DNS  01 , where it locates the DNS  03  for the “ORG” network, and further locates the DNS  06  for the MCN network  100 , and eventually it locates AOL.COM.MCN.ORG. In responding to the lookup request from the client device  101 , the DNS system returns the unique IP address for AOL.COM.MCN.ORG to the client  101 . This unique IP address is automatically cached in the DNS along the returning route, i.e., DNS  06  →DNS  03 →DNS  01  DNS  02 →DNS  05 . Note that the critical point is that the DNS lookup is distributed and ached, and as a result, the DNS lookups cannot be centrally monitored by any participant of the federation. 
     In an equivalently preferred embodiment of the invention, the distributed authentication system supported by the MCN network  100  includes a default server  114  with a FQDN DEFAULT.MCN.ORG. If the DNS lookup totally fails, i.e. the domain included in the lookup request sent by the client device  101  is not recognized by the DNS  200 , a DNS resolver in the central location of the DNS  200  can automatically map the unrecognized domain to the default server  114 . The default server  114  takes responsibility to authenticate the user by looking up its local database. The end result is that all possible MCN ID&#39;s are automatically distributed to the appropriate servers. 
     Once the client  101  received the IP address of the targeted authentication server, i.e. AOL Authentication Server  111  in our example, it sends the user&#39;s user name joe with his password secret911 to AOL Authentication Server  111  for authentication. When AOL Authentication Server  111  receives the request, it looks up its local database DB  01  for the user entry, validates the user name and password, and sends an authentication token back to the user. The authentication token is cached in the client device. When the user sends request to any participant servers, the authentication token is automatically attached. The attached authentication token is recognized by any participant server of the federation and is automatically cached in the participant server&#39;s database when the participant server receives the authentication token. In this way, the user&#39;s detailed authentication information is stored only in one participant server&#39;s authentication database, but the authentication token is distributed all over the participants&#39; authentication databases. Because an authentication server does not need to store every user&#39;s detailed authentication information, its authentication database can be relatively small in size. 
     In another equivalently preferred embodiment, the client portion of the authentication system has a mapping list of the fully qualified domain names (FQDN) for all registered authentication servers. When the user gets logged in, the system parses and extracts the domain portion from the user&#39;s GUID, and directly checks the mapping list to find the IP address for the target authentication server. If the local list checkup fails, the authentication request may be automatically mapped into the default authentication server  114  as described above. 
     In another equivalently preferred embodiment, the local list checkup and the DNS lookup may be combined. For example, the system first checks the local mapping list. If the target authentication server&#39;s IP address is not found from the mapping list, then start the DNS lookup process. If the DNS lookup fails, then automatically map the unrecognized domain to the default server  114  as described above. 
     In another equivalently preferred embodiment, all participants are not registered in a specific domain. Instead, each participating authentication server is registered with a standard server name in its main server&#39;s domain. For example, AOL Authentication Server  111  has a FQDN AUTH.AOL.COM, USPTO&#39;s authentication server has a FQDN AUTH.USPTO.GOV, etc. In other words, the host names of these authentication servers share a common prefix, but they reside in different domains. When the user gets logged in, the authentication system first parses and extracts the domain portion of the GUID. Then, it either checks a local mapping list or looks up the DNS  200  or performs both local list checkup and DNS lookup to locate the IP address for the target authentication server. If the IP address for the target authentication server is not found, the system may map the authentication request to the default server  114  as described above. 
       FIG. 2  is a flow diagram illustrating a process  220  for providing distributed authentication service according to one embodiment of the invention. The distributed authentication service is provided via a network with a unique domain name. The network includes a number of participating authentication servers and a number of clients. The network&#39;s domain name is used as a common suffix for all participating servers&#39; FQDN. For example, for all participants of the MCN network  100 , the common suffix of their FQDN is MCN.ORG and AOL Authentication Server&#39;s FGDN is AOL.COM.MCN.ORG. The process includes the steps of: 
     Step  221 . The user logs in by entering his global user identification (GUID) and his password. The GUID includes his user name followed by a delimitation symbol and a domain portion which is the domain name of the server with which the user registered. For example, an AOL registered user joe has a GUID joe @aol.com. 
     Step  222 . Parse the GUID and extract the domain portion. For example, extract aol.com from GUID joe@aol.com. 
     Step  223 . Append the domain name of the network as a suffix to the extracted domain portion from the GUID to form a fully qualified domain name (FQDN). 
     Step  224 . Consult DNS for the FQDN&#39;s IP address. For example, the DNS  200  locates AOL.COM.MCN.ORG from the MCN database DB  16  and returns its IP address. 
     Step  225 . Send user name and password to the target authentication server. For example, sends joe and secret911 to AOL Authentication Server  111 . 
     Step  226 . Carry out the authentication at the target authentication server. 
     Step  227 . Cache and distribute the authentication result which is recognized by all authentication servers registered in the network. 
     As an option, the process  220  may further include: 
     Step  224 B. If the DNS look up fails, automatically send the user name and password to a default server for authentication. 
       FIG. 3  is a flow diagram illustrating a process  230  for providing distributed authentication service according to another preferred embodiment of the invention. The distributed authentication service is provided via a network with a unique domain name. The network includes a number of participating authentication servers and a number of clients. The network&#39;s domain name is used as a common suffix for all participating servers&#39; FQDN. For example, for all participants of the MCN network  100 , the common suffix of their FQDN is MCN.ORG and AOL Authentication Server&#39;s FGDN is AOL.COM.MCN.ORG. The process  230  includes the steps of: 
     Step  231 . The user logs in by entering his global user identification (GUID) and his password. The GUID includes his user name followed by a delimitation symbol and a domain portion which is the domain name of the server with which the user registered. For example, an AOL registered user joe has a GUID joe@aol.com. 
     Step  232 . Parse the GUID and extract the domain portion from the GUID. For example, extract aol.com from GUID joe@aol.com. 
     Step  233 . Append the network&#39;s domain name as a suffix to the extracted domain portion from the GUID to form a fully qualified domain name (FQDN). 
     Step  234 . Consult a predefined local mapping list of the FQDN&#39;s for all registered authentication servers to obtain an IP addresses for the FQDN formed in Step  233 . In the mapping list, each FQDN is mapped to a unique IP address. This approach suits for scenario where the distributed authentication federation has a static and small list of participants. 
     Step  235 . Send user name and password to the target authentication server. For example, sends joe and secret911 to AOL Authentication Server  111 . 
     Step  236 . Carry out the authentication at the target authentication server. 
     Step  237 . Cache and distribute the authentication result. 
     As an option, the process  230  may further include: 
     Step  234 A. If the IP address cannot be found from the local mapping list, automatically send the user name and passport to a default server for authentication. 
       FIG. 4  is a flow diagram illustrating a process  240  for providing distributed authentication service according to another preferred embodiment of the invention. The distributed authentication service is provided via a network with a unique domain name. The network includes a number of participating authentication servers and a number of clients. The network&#39;s domain name is used as a common suffix for all participating servers&#39; FQDN. For example, for all participants of the MCN network  100 , the common suffix of their FQDN is MCN.ORG and AOL Authentication Server&#39;s FGDN is AOL.COM.MCN.ORG. The process  240  includes the steps of: 
     Step  241 . The user logs in by entering his global user identification (GUID) and his password. The GUID includes his user name followed by a delimitation symbol and a domain portion which is the domain name of the server with which the user has registered. For example, an AOL registered user joe has a GUID joe@aol.com. 
     Step  242 . Parses the GUID and extracts the domain portion. For example, extract aol.com from GUID joe@aol.com. 
     Step  243 . Append the network&#39;s domain name as a suffix to the extracted domain portion from the GUID to form a fully qualified domain name (FQDN). 
     Step  244 . Consult a predefined local mapping list of the FQDN&#39;s for registered authentication servers to obtain an IP addresses for the FQDN formed in Step  243 . In the mapping list, each FQDN is mapped to a unique IP address. 
     Step  244 A. If Step  244  fails, consult DNS for the FQDN&#39;s IP address. For example, the DNS system locates AOL.COM.MCN.ORG from the MCN database DB  16  and returns its IP address. This approach balances performance efficiency and adaptation of dynamic changes of the participant list. 
     Step  244 B. If Step  244 A fails, automatically send the user name and password to a default server for specific authentication. 
     Step  245 . Send user name and password to the target authentication server. For example, sends joe and secret911 to AOL Authentication Server  111 . 
     Step  246 . Carry out the authentication at the target authentication server. 
     Step  247 . Cache and distribute the authentication result. 
       FIG. 5  is a flow diagram illustrating a process  250  for providing distributed authentication service according to another preferred embodiment of the invention. The process  250  includes the steps of: 
     Step  251 . The user logs in by entering his global user identification (GUID) and his password. The GUID includes his user name followed by a delimitation symbol and a domain portion which is the domain name of the server with which the user has registered. For example, an AOL registered user joe has a GUID joe @aol.com. 
     Step  252 . Parses the GUID and extracts the domain portion. For example, extract aol.com from GUID joe@aol.com. 
     Step  253 . Prepend a predefined parameter (e.g., “AUTHENTICATION” or “AUTH”) representing a standard authentication server name as a prefix to the extracted domain portion from the GUID to form a fully qualified domain name (FQDN) in its main server&#39;s domain. This FQDN is same as the registered domain name of a target authentication server. For example, AOL Authentication Server&#39;s FQDN is AUT.AOL.COM. 
     Step  254 . Consult a predefined local mapping list of the FQDN&#39;s of all registered authentication servers to obtain an IP addresses for the FQDN formed in Step  253 . In the mapping list, each FQDN is mapped to a unique IP address. 
     Step  254 A. If Step  254  fails, consult DNS for the FQDN&#39;s IP address. For example, the DNS system locates AUTH.AOL.COM from a certain MCN database and returns its IP address. This approach balances performance efficiency and adaptation of dynamic changes of the participant list. 
     Step  254 B. If Step  254 A fails, automatically send the user name and password to a default server for specific authentication. 
     Step  255 . Send user name and password to the target authentication server. For example, sends joe and secret911 to AOL Authentication Server  111 . 
     Step  256 . Carry out the authentication at the target authentication server. 
     Step  257 . Cache and distribute the authentication result to the client. 
     Definition: In this document, “fully qualified domain name (FQDN)” means a full site-name, which consists of (1) a local host name, and (2) a domain name. The suffix of the domain name is a top-level domain (tld). For example, AUTH.AOL.COM is a FQDN, in which AUTH is its local host name; AOL.COM is its domain name; and .COM is a top-level domain. For another example, AOL.COM.MCN.ORG is a FQDN, in which AOL.COM is its local host name; MCN.ORG is its domain name; and ORG is a top-level domain. 
     Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention. 
     Accordingly, the invention should only be limited by the claims included below.