Abstract:
In electronic commerce (e-commerce) sites that are executed on a single e-commerce application, a user&#39;s session is only associated with a single user identity for e-commerce site domain. Acting under a single identity across the site may not be desired. There may be requirements to associate an individual user with one or more separate identities within parts of the site. Aspects of the invention provide a method, system and computer program product for managing multiple user identities for a user of an electronic commerce (e-commerce) site. The method comprises defining the e-commerce site as one or more security domains; and in response to a user&#39;s request to invoke an operation of the e-commerce site: determining a one of the one or more security domains to which the operation relates; performing one of a) creating a session and b) reusing a session for the user automatically in accordance with the determined security domain, said session associated with a user identity and a role indicating privileges for invoking operations of the e-commerce site in at least the determined security domain; and persisting said session for reuse. The user&#39;s request may be received in association with one or more sessions persisted for the user and a one of the sessions selected in accordance with the determined security domain. In response, either a session may be created or reused. Persisting may comprise providing one or more cookies defining the session to the user for associating with a subsequent request. In accordance with a feature of this aspect, the e-commerce site may define each of the one or more security domains as a hierarchy of organizations and assets owned by the organizations and the determining a one of the one or more security domains to which the operation relates may comprise evaluating the user&#39;s request in accordance with the hierarchy.

Description:
FIELD OF THE INVENTION 
   The present invention relates to application operation and development, more particularly, to managing multiple identities for a user of an electronic commerce site. 
   BACKGROUND OF THE INVENTION 
   Electronic commerce (e-commerce) relates to the electronic performance of transactions for goods or services. One component of e-commerce application operation is security, particularly user security. Security enables a user of the e-commerce application to be authenticated and provided permission to invoke certain functions of the e-commerce application while preventing certain functions from invocation by users who cannot be authenticated or who do not have a required permission. One aspect of user security is identity management which distinguishes individual users and associates an individual user&#39;s identity with the user&#39;s requests and activities during an e-commerce session. 
   E-commerce applications are typically made available to users via a network such as the Internet at an Internet site or domain defined by one or more universal resource locators (URLs). Pages identified by URLs for the site may be browsed by a user with a client browsing application (web browser) that requests the pages from one or more servers hosting the site. E-commerce functions may be invoked by the user to initiate and conclude e-commerce transactions via the web browser. 
   Browsing purely in accordance with the hyper text transfer protocol (HTTP) of the Internet is stateless: a previous user request to a site has no bearing on a current user request to the site. To maintain a state between an HTTP client and a server, a piece of data known as a cookie is used. The cookie is issued by the server to the client. To identify itself to the server on a subsequent request, the client browsing application submits the cookie as part of a subsequent request header. From information in the cookie the server can identify the client, thus maintaining a state across requests. 
   Cookies are a popular means of managing user sessions in e-commerce sites. When a user visits a site or authenticates to a site, a cookie is issued to the user to identify the user to the site for the life of the user&#39;s session (e.g. until the user closes the web browser or invokes a logoff function on the site). 
   Within an Internet domain, one or more security domains may be defined using a collection of related URLs and a user may be assigned the same privileges throughout a particular security domain. For the Internet domain shop.ibm.com, the following is an example of two security domains, one for each of store A and store B and where ... represents any string of characters like a wildcard placeholder: 
   i) URLs matching the pattern http://shop.ibm.com/...?...&amp;storeId=A&amp;... 
   ii) URLs matching the pattern http://shop.ibm.com/...?...&amp;storeId=B&amp;... 
   One or more security domains may be used to define an e-commerce shopping mall, e-commerce hosting site, e-commerce marketplace, or other place where online business is conducted. The aggregation of all the security domains in an e-commerce site is called the composite security domain. 
   In e-commerce sites that are executed on a single e-commerce application, a user&#39;s session is only associated with a single user identity for the composite security domain. Acting under a single identity across security domains may not be desired. There may be requirements to associate an individual user with one or more separate identities within each security domain or subset of security domains that form a composite domain. For example, if a user is browsing two independent stores at an Internet site and has added items to the user&#39;s shopping cart in both stores, it may be desired that the business logic of the e-commerce application only displays the shopping cart associated with the one store that the user is currently browsing. If the user wants to be treated under a common identity in two hosted stores but a different identity under a third store, the business logic to achieve this result is very complicated. 
   Gathering statistics of user activities at a particular store is much easier to perform with user identities that are only associated with the particular store than with user identities that are associated with multiple hosted stores. Merchants choosing to have their store in a hosted shopping mall often do so for reasons of affordability, sharing processing resources with other
         merchants to reduce costs. One consequence is that these merchants share their user&#39;s customer accounts among all the stores in the shopping mall. If a hosted store desires to move to its own e-commerce site, migration of customer accounts, including individual shopping carts and orders, may be very difficult or costly if the accounts and carts are shared with other stores.       

   As such, an identity management architecture which addresses some or all of these shortcomings is desired. 
   SUMMARY OF THE INVENTION 
   In one illustrative embodiment, a method is provided for managing multiple user identities for a user of an electronic commerce (e-commerce) site. The illustrative embodiment defines the e-commerce site as a plurality of security domains. In response to a user&#39;s request to invoke an operation of the e-commerce site, the illustrative embodiment identifies a type of user identity being used by the user. In the illustrative embodiment, types of user identities comprise guest identity, a generic identity, and a registered identity. In the illustrative embodiment, the generic identity is a single user identity shared throughout a security domain. In the illustrative embodiment, the guest identity is an unique temporary user identity assigned to a user for the life of the users session within the security domain. In the illustrative embodiment, the registered identity is an unique identity that is reusable across sessions within the security domain. The illustrative embodiment determines if the type of user identity is appropriate to invoke the operation. Responsive to the type of user identity being an inappropriate type of user identity to invoke the operation, the illustrative embodiment switches the user to the appropriate type of user identity to invoke the operation. Responsive to the type of user identity being appropriate to invoke the operation, the illustrative embodiment determines a security domain of the plurality of security domains to which the operation relates. The illustrative embodiment selects a session from a plurality of sessions persisted for the user based on the determined security domain. The illustrative embodiment reuses the selected session for the user automatically in accordance with the determined security domain, the selected session being associated with a user identity and a role, the user identity and the role together indicating privileges for invoking operations of the e-commerce site in the determined security domain. 
   These and other features and advantages of the present invention will be described in, or will become apparent to those of ordinary skill in the art in view of, the following detailed description of the illustrative embodiments of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the figures which illustrate an example embodiment of this invention: 
       FIGS. 1A ,  1 B,  1 C and  1 D schematically illustrate respective exemplary e-commerce market models, namely, a shopping mall site, a hosted store site, a multiple go to market site and a marketplace site, embodying aspects of the invention; 
       FIG. 2  schematically illustrates a portion of a computer system, namely a memory, embodying aspects of the present invention; 
       FIG. 3  illustrates a state diagram modeling an aspect of the present invention shown in  FIG. 2 ; 
       FIG. 4  illustrates a further state diagram modeling an aspect of the present invention shown in  FIG. 2 ; 
       FIG. 5  illustrates in flowchart form operations of an aspect of the invention shown in  FIG. 2 . 
   

   DETAILED DESCRIPTION 
   The following detailed description of one or more embodiments of the present invention does not limit the implementation of the invention to any particular computer programming language. The present invention may be implemented in any computer programming language provided that the OS (Operating System) provides the facilities that may support the requirements of the present invention. A preferred embodiment is implemented in the Java computer programming language (or other computer programming languages in conjunction with Java). Any limitations presented would be a result of a particular type of operating system or computer programming language and would not be a limitation of the present invention. 
   In accordance with the present invention, there is provided a technique for managing multiple identities for a user in an e-commerce site. As previously noted, one or more security domains may be used to define virtual places where online business is conducted, examples of which are depicted in  FIGS. 1A ,  1 B,  1 C and  1 D ( FIGS. 1A-1D ).  FIGS. 1A-1D  depict an exemplary e-commerce shopping mall site, e-commerce hosted stores site, e-commerce multiple go to market site and e-commerce marketplace site, respectively. Though not illustrated, in accordance with an aspect of the invention, each of the sites is implemented by a networked computer system including a server having one or more CPUs and a memory configured with computer instructions (i.e. applications and data) in accordance with a further aspect of the invention as described herein below. Throughout the description herein, an embodiment of the invention is discussed with aspects of the invention embodied on a sole computing device. As will be appreciated by those of ordinary skill in the art, aspects of the invention may be distributed amongst one or more networked computing devices which interact via one or more data networks such as, for example, the Internet. However, for ease of understanding, aspects of the invention have been embodied in a single computing device. 
   The computer instructions/applications stored in the memory and executed by the CPU (thus adapting the operation of the computer system as described herein) are illustrated in functional block form in  FIG. 2 . As will be appreciated by those of ordinary skill in the art, the delineation between aspects of the applications illustrated as functional blocks in  FIG. 2  is somewhat arbitrary as the various operations attributed to a particular application as described herein may, in alternative embodiments, be subsumed by another application. 
     FIG. 2  illustrates the memory configured in accordance with the present invention for providing an e-commerce site, such as those of  FIGS. 1A-1D , including a manager for managing multiple identities for a user of the site. Briefly,  FIG. 2  illustrates memory  200 , which may comprise one or more of both volatile and persistent memory for the storage of: operational instructions for execution by the CPU, data registers, application storage and the like. Memory  200  preferably includes a combination of random access memory (RAM), read only memory (ROM) and persistent memory such as that provided by a hard disk drive (all not shown). As illustrated, for exemplary purposes only, memory  200  stores OS  202 , communications suite  204 , e-commerce application server (EAS)  206  adapted with multiple identity manager (manager)  208  and a plurality of cookies  210 ,  212  for assigning a user identity and role to a user visiting a security domain defined by EAS  206  as discussed further herein below. 
   OS  202  is an operating system suitable for operation with the CPU of the computer system and the operations described herein. Multitasking, multithreaded OSes such as, for example, IBM AIX™, Microsoft Windows NT™ (NT is a bit dated it is better to use Microsoft Windows 2000), Linux or the like, are expected in many embodiments to be preferred. Communication suite  204  provides, through, interaction with OS  202  and a network interface (not shown) of the computer system, suitable communication protocols to enable communication with other networked computing devices via a network (also not shown) such as the Internet. Communication suite  204  may include one or more of such protocols such as TCP/IP, Ethernet, token ring and the like. 
   Also stored in memory  200  and incorporating aspects of the present invention is EAS  206  adapted by manager  208 . In the exemplary embodiment, EAS  206  provides substantially all of the functionality needed to establish the e-commerce site including each electronic store and to carry out buying and selling over the Internet. This includes storing product catalog information provided by sellers or distributors, accepting requests for information from prospective user purchasers, and accepting and processing orders. The electronic store typically includes a collection of Web pages which describe a sellers&#39; product offerings and which include on-line forms allowing users to place orders as is known to those skilled in the art. As earlier stated, though EAS  206  is shown stored in memory  200  of a single computer system, it is understood to persons skilled in the art that components of EAS  206  may be stored on additional computer systems networked with the computer system having memory  200 . 
   Unlike conventional EASs, EAS  206  is adapted to have a multiple identity management capability via a manager  208 . That is, EAS  206  is adapted to provide e-commerce operations to a user in association with multiple identities managed by manager  208  for one or more security domains defined for the e-commerce site of EAS  206 . 
     FIG. 1A  illustrates an exemplary e-commerce shopping mall site  100  defined by an e-commerce application such as EAS  206  comprising a plurality of stores on one site where users can shop. Typically, users are recognized by e-commerce application  204  adapted by multiple identity manager  208  and given the same privileges for all the stores in the mall  100 . Thus the mall  100  has one security domain. Organizations  110  (depicted as ovals), may own or otherwise control other organizations  110 , users  112  (depicted as cubes) and/or stores  104  (depicted as pyramids). Stores  104  comprise a set of related URLs and may be assigned a store identifier (ID), that is represented in the URL by the parameter storeId. Thus the set of URLs that belong to a store  104  for a particular Internet domain matches the pattern http://&lt;Internet domain name&gt;/...?...&amp; storied=x&amp;..., where x is the ID of the store  104 . In this mall  100  all the stores  104  form one security domain. Thus from the depiction in  FIG. 1A , if the mall  100  is hosted on the site “shop.ibm.com”, then the three URL patterns http://shop.ibm.com/...?...&amp;storeId=A&amp;..., http://shop.ibm.com/...?...&amp;storeId=B&amp;..., and http://shop.ibm.com/...?...&amp;storeId=C&amp;... form one security domain. 
   Typically, e-commerce sites can cost many millions of dollars to setup and maintain. Merchants who cannot afford their own online store or those who chose otherwise have the alternative of using a hosted store site that hosts multiple independent stores. An alternative exemplary e-commerce site, namely an e-commerce hosted store site  120 , shown in  FIG. 1B , comprises a plurality of stores  122 ,  124 ,  126 ,  128  and  130  executing within a single e-commerce application such as EAS  206 .  FIG. 1B  depicts each hosted store  122  and  124  being owned by its own respective hosted organization  132  and  134 . All hosted organizations  132  and  134  are in turn owned by the Hosted Seller Org  136 . For the creation and management of the hosted organization and its hosted store the management store (Mngt Store)  126  is used. 
   Running the hosted site  120  in a single e-commerce application  206  is desirable as it has a number of advantages:
         i) Running many small stores in a single application is more likely to make efficient use of processor time than a single small store.   ii) Stores can share common resources such as web pages and product catalogs.   iii) Maintenance costs for many stores in a single application are much less than having one store per application.       

   In  FIG. 1B , store A  122  and store B  124  each have their own security domain. The Mngt store  126  also has its own security domain. 
     FIG. 1C  illustrates a further alternative site configuration, namely an exemplary e-commerce multiple go to market site  140  executing in a single e-commerce application such as EAS  206 . Each independent seller (e.g. A, B and C) has its own store  142 ,  144 , and  146  and top-level organization  148 ,  150  and  152 , (i.e. SellerA, SellerB, and SellerC). These seller organizations  148 ,  150  and  152  are owned by a common parent organization  154 , namely, B2C Org. This site configuration  140  is very similar to the hosted store site  120  of  FIG. 1B . However, that e-commerce site model  120  is extended in this configuration  140  as a single seller (e.g. A) is able to sell customized products in various specialty stores  156  and  158 . For example, a seller may have a general purpose store, a store targeting infant needs, a store targeting women&#39;s apparel, a store targeting bargain hunters, etc. These specialty stores are each be owned by a separate organization which in turn is owned by one of the top-level seller organizations. SellerA  148  in  FIG. 1C  is an example of such a top-level seller organization. In this example, store A  142  is the general purpose store, while store X  156  and store Y  158  are specialty stores, targeting niche markets. 
   In a multiple go to market model such as exemplary configuration  140 , a specialty store constitutes its own security domain. For example, a shopper who registers to store X  156  is not granted any privileges in store A  142  or store Y  158 . However, a top-level organization and its sub-organizations can together form a security domain when privileges are assigned at the top-level organization level. For example, a shopper who registers to store A  142  is granted privileges in stores A, X and Y ( 142 ,  156  and  158 ). 
     FIG. 1D  illustrates another exemplary e-commerce site, namely e-commerce marketplace site  160  executing in a single e-commerce application  206 , such as EAS  206  where resellers offer their items for sale in independent stores to the general public. However, unlike the hosted store site  120  of  FIG. 1B , in this model  160  resellers purchase products from various distributors via a marketplace store. The distributors only sell their goods to resellers and not to the general public. 
   Each reseller (e.g. A and B) has their own store  162  and  164  and organization  166  and  168 . The reseller organizations  166  and  168  are owned by a top level organization  170 , namely, Reseller Org. The marketplace store, referenced as channel store  172  is owned by the organization, Channel Org  174 . There are two types of distributors depicted in the model. These are hosted distributors  176  and proxy distributors  178 . Hosted distributors  178  have their stores (e.g.  180 ) hosted on the site  160  and under the organization Distributor Org  182 . Proxy distributors  178  have an independent site (not shown) but use a proxy store (e.g.  184 ) under a proxy organization  186  to bridge the connection between the resellers and the independent distributor stores. 
   There are many security domains illustrated in  FIG. 1D . Each reseller store ( 162 ,  164 ) has its own security domain. Channel store  172  is another security domain. All the distributor proxy organizations  186  form a security domain. And finally, all distributor organizations  182  define a further independent security domain. 
   In accordance with the invention, manager  208  assigns one of three types of privileges to users within a security domain. These are guest, registered, and administrative. Guest privileges are assigned to users who have a temporary relationship with the security domain. Registered privileges are assigned to users who have a permanent relationship with the security domain but do not have any administrative privileges within that domain. Administrative privileges are assigned to users who have a permanent relationship with the security domain and have the ability to perform administrative management operations within the domain. As users navigate the e-commerce site and request particular operations, manager  208  may assign different or additional types of privileges as described further below. 
   Typically, users with guest privileges can perform a limited set of operations in a security domain, e.g. browsing the catalog, placing an isolated order, etc. If a user intends to do various e-commerce transactions in a store over a period of time, there may be a benefit to having a permanent relationship with the security domain by obtaining registration privileges. In this way, the user can later authenticate to the security domain and view his order history, address book, etc. Security domains may be configured to only allow users with registered privileges to access the store&#39;s assets, e.g. catalog, address book, etc. Users with administrative privileges can perform management operations such as resetting a the password of a user within the security domain. 
   Access control roles are used to distinguish the type of privileges a user has within a security domain. A user with guest privileges has no access control role within the security domain. A user with registered privileges has a single access control role within the domain known as the Registered Customer role. Users with administrative privileges may have one or more administrative roles within a security domain. 
     FIGS. 1A-1D  each depict a tree-like hierarchy of organizations, stores and users where users and stores may only be leaf nodes of the tree. As depicted in  FIGS. 1A-1D , organizations are used to group stores. Organizations only have one owner, known as their parent organization, but may own many organizations, known as the descendant organizations. Organizations own assets. One such asset is a store. Each store is owned by a single organization, however an organization may own multiple stores. Stores do not own other stores. 
   Access control roles are associated with organizations. A user that plays a particular role in an organization, also plays the role in any of that organization&#39;s descendant organizations and assets. A user assigned a role for a particular organization grants to the user rights to a subset of URLs associated with the organization&#39;s stores. 
   Organizations are used to define the scope of a security domain. Since organizations are hierarchical in nature, the security domain can be defined as encompassing an organization and its descendants. Thus a user is granted the same set of privileges for assets owned by an organization and all its descendants. 
   To support multiple identities in a composite security domain, a person may be assigned one user ID per security domain or subset of security domains. There are three types of user IDs within a security domain. These are generic, guest, and registered. The generic type is a single user ID shared throughout the security domain. The main purpose for this type of user ID is performance and scalability. The guest type is an unique temporary user ID assigned to a user for the life of the user&#39;s session within a security domain. The registered type is an unique identity that is reusable across sessions within a security domain. A user ID that is of the registered type for a particular security domain must have an access control role within the security domain. A registered type user ID may be shared across security domains, by having an access control role in each domain. However, a generic ID or guest user ID cannot be shared across domains. 
   When a user invokes an operation in a security domain, a determination is made as to whether the type of the current user ID to perform the operation is appropriate. This does not necessarily mean that the user ID has the required privileges to perform the operation. If the operation being invoked will not result in a resource being associated with the user, for example, displaying a product page, then a generic, guest, or registered identity is sufficient. If the operation will result in a resource being associated with a user, then the guest or registered identity is sufficient. An operation such as adding an item to a shopping cart will result in a item resource being associated with the identity. If the operation requires the user to have a permanent relationship with the security domain, then the user ID must be of the registered type. 
   If the type of user ID is not sufficient for invoking an operation within a security domain the user ID type may be switched to a more appropriate type. Manager  208  maintains user types for a particular user, as the user navigates the e-commerce site and requests operations via commands.  FIG. 3  is a state diagram that illustrates states and transitions  300  for maintaining user types within a security domain as performed by manager  208   
   Operation of manager  208  may be understood with reference to an exemplary shopping session by a user at a store such as store A  122  of  FIG. 1B . Store A  122  corresponds to a security domain. A typical shopping scenario and the corresponding state transition is outlined below as may be further understood with reference to  FIG. 3 :
         1) A user opens a client browser and accesses the store front page of the e-commerce site  120  sending an HTTP request to invoke a command on EAS  206 . In response, manager  208  assigns the user (i.e. the client browser) the generic user identity (State  302 ).   2) A product display page of site  140  is accessed via a command through the client browser and an item is selected for placement in a shopping cart as a potential product to purchase. The command requires an user identity type other than generic. Thus manager  208  creates a unique guest user identity and assigns it to the client browser, transitioning to state  304 .   3) The user registers to store A  122  via a command. Manager  208  creates and assigns a unique registered user identity to the client browser, transitioning to state  306 .   4) When the user logoffs store A  122 , manager  208  transitions to state  302  and assigns a generic user identity to the browser.   5) When the user closes its client browser, the cookies are cleared from the client browser memory.       

   In the exemplary embodiment of the invention, cookies are used to manage the various user IDs when a user invokes operations on a security domain. Two cookies are used for each user ID: an authentication cookie and a session cookie. 
   Authentication Cookie 
   The authentication cookie is used to authenticate the user on every request to the security domain. In the exemplary embodiment, the authentication cookie comprises two parts:
         i) A user ID associated with the client browser (i.e. user) for the particular security domain. Each authentication cookie has a unique user ID.   ii) A one-way hash of the user ID, a timestamp unique to this user ID and an encryption key unique to the composite security domain. The timestamp associated with the user ID is persisted by manager  208 , for example using memory  200 , for subsequent confirmations of the user as a security and integrity measure.       

   Manager  208  verifies the authentication cookie on every request made by the client. Manager  208  first strips the security ID from the cookie value and constructs a one-way hash using the same algorithm described above. The new constructed hash string is compared to that in the cookie value, only if they match is the cookie considered valid. 
   User Session Cookie 
   The user session cookie contains session information for a particular security domain. For every authentication cookie there is an equivalent user session cookie. The user session cookie comprises four parts:
         i) The user ID associated with this session.   ii) User preferences such as language and currency.   iii) A list of store IDs that this user is authorized to access. Associated with each storeID is a list of the user preference information for this store.   iv) A signature for this cookie such as a one-way hash of the above three parts (will be referred to as the value part) plus an encryption key unique to the site.       

   Table 1, below illustrates the format of the authentication and user session cookies. 
   
     
       
             
           
             
             
             
             
           
         
             
               TABLE 1 
             
           
           
             
                 
             
             
               Example of the authentication and user session cookie pairs. 
             
           
        
         
             
               Authentication 
               Authentication 
                 
                 
             
             
               Cookie 
               Cookie 
               User Session Cookie 
               User Session Cookie 
             
             
               Name 
               Value* 
               Name 
               Value* 
             
             
                 
             
             
               AUTH —   
               userId1, 
               USERSESSION_USERID1 
               userId1, 
             
             
               USERID1 
               one-way 
                 
               language, currency, 
             
             
                 
               hash(encryption key + 
                 
               [storeId A, . . . ], 
             
             
                 
               userId1 + user1&#39;s 
                 
               [storeId B, . . . ], 
             
             
                 
               timestamp) 
                 
               one-way hash(encryption 
             
             
                 
                 
                 
               key + value part of this 
             
             
                 
                 
                 
               cookie) 
             
             
               AUTH —   
               userId2, 
               USERSESSION_USERID2 
               userId2, 
             
             
               USERID2 
               one-way 
                 
               language, currency, 
             
             
                 
               hash(encryption key + 
                 
               [storeId Y, . . . ], 
             
             
                 
               userId2 + user2&#39;s 
                 
               one-way hash(encryption 
             
             
                 
               timestamp) 
                 
               key + value part of this 
             
             
                 
                 
                 
               cookie) 
             
             
               . . . 
               . . . 
               . . . 
               . . . 
             
             
               AUTH —   
               userIdn, 
               USERSESSION_USERIDn 
               userIdn, 
             
             
               USERIDn 
               one-way 
                 
               language, currency, 
             
             
                 
               hash(encryption key + 
                 
               [storeId Z, . . . ], 
             
             
                 
               userIdn + usern&#39;s 
                 
               one-way hash(encryption 
             
             
                 
               timestamp) 
                 
               key + value part of this 
             
             
                 
                 
                 
               cookie) 
             
             
                 
             
           
        
       
     
   
   Cookie values may be encoded to ensure they comply with any restricted character set requirements as will be understood by persons of ordinary skill in the art. 
   Processing a Request 
     FIG. 4  is a state diagram that illustrates states and transitions  400  showing how an e-commerce operation request is processed in a security domain in accordance with the exemplary embodiment of the invention by EAS  206 . Further details of the operation of EAS  206  and manager  208  are illustrated in  FIG. 5 . With reference to  FIG. 4 , the operation on EAS  206  invoked by a user request can be broken down in to several parts.
         i) Session Initialization (State  402 ) determines what user ID will be used during processing of the request.   ii) Command Execution (State  404 ) comprises the processing of the business process logic for the e-commerce site, which processing may result in a change to the user ID, the user session information or both.   iii) Session Commit (State  406 ) is responsible for persisting any changes in the authentication information or user session information to the client browser.   iv) Session Rollback (State  408 ) unwinds any changes that were made during command execution if an exception occurs, resulting in the request processing being aborted.
 
Session initialization (State  402 ) commences upon receipt of an HTTP request from the client browser. An HTTP response results from either of Session Commit (State  406 ) or Session Rollback (State  408 ) and may be written to a response buffer (not shown) of memory  200  for communicating to the client browser.
       
   In accordance with an aspect of the invention,  FIG. 5  illustrates method steps  500  of EAS  206  including manager  208 , highlighting operations at various stages of successful request processing. With reference to  FIG. 4 , steps  502 - 518  generally illustrate the activities that occur during session initialization (Stage  402 ); step  520  represents command execution (Stage  404 ); and steps  522 - 530  illustrate a session commit (Stage  408 ). With reference in greater detail to  FIG. 5 , request processing that occurs when an operation is invoked in a security domain defined by EAS  206  and manger  208  is further described. 
   When an HTTP request arrives at EAS  206  from a client browser (step  502 ), all the cookies in the request are parsed from its header. The authentication cookie and its associated user session cookie are paired together to define a single session element. The session elements are strung together in a list. 
   The current security domain is determined from information specified in the URL of the HTTP request (step  502 ). At Step  506 , the session list is iterated to determine if there is a session that already exists for the security domain or if not then does a user from an existing session play a role in the current security domain. If a session does exist, processing continues at step  516 . 
   At step  508 , a determination is made whether the command being executed is a generic command and processing continues at step  510  if it is generic and otherwise proceeds to step  514 . At step  510 , the user ID is set to the generic user and at step  512  the user ID and other session information is made available to the business logic during its execution. 
   At alternate step  514 , a new guest user is created before execution of step  512 . At alternate step  516 , as it has been determined that there is an existing session for the domain, the authentication cookie is verified and the user session information is deserialized from the session cookie. At step  518 , if the user ID is a generic type then processing continues at step  508  as previously described. Otherwise, processing continues at step  512  using the information retrieved from the cookies. 
   From step  512 , processing continues at step  520  where the business logic is executed. As described above with reference to  FIG. 4 , the business logic may change the user ID or the other session information. 
   As such, at step  522 , changes done during the business logic execution are made available to the session commit. At step  524  a determination is made whether the user ID was changed in any of the previous steps. If the user ID did not change in the session, processing may end (step  526 ); otherwise, the user ID changed in the session and at step  528 , a determination is made as to whether there was a previous session for the current security domain. 
   If there was no previous user ID associated with this security domain, manager  208  creates and persists a new session for the user ID associated with the current security domain (step  530 ). If a previous session does exist, it is first deleted (step  532 ) before executing step  530  to clean up the previous session. 
   Operation of EAS  206  and manager  208  may be further understood by way of an exemplary user shopping scenario. In accordance with this example, EAS  206  defines exemplary e-commerce shopping mall site  120  as illustrated by  FIG. 1B  providing stores A and B ( 122 ,  124 ) each defined within respective security domains. In further accordance with this example, a user has previously registered to stores A and B ( 122 ,  124 ) under different user IDs, namely user ID α in store A  122  and user ID β in store B  124 . This exemplary user shopping scenario describes operation of manager  208  and the cookies it generates while the user 1) shops at store A  122  as a generic user; 2) logs in as user ID α; 3) adds an item to a shopping cart as user ID α; 4) proceeds to store B  124  as a guest; and 5) logs in to store B  124  as user ID β; and 6) logs off store B  124 . 
   
     
       
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
             
             
             
             
           
         
             
                 
                 
             
           
           
             
                 
               1) 
               User Operation: 
               User opens a client browser and accesses store A at a URL, e.g. 
             
             
                 
                 
                 
               shop.ibm.com/. . . StoreFront?storeId = A&amp;langId = En&amp;curId = 
             
             
                 
                 
                 
               US. 
             
             
                 
                 
               Manager Operation: 
               Session Initialization: Determines there is no current user ID for 
             
             
                 
                 
                 
               store A. Sets User ID to Generic User; Command Execution: 
             
             
                 
                 
                 
               performs request processing; Session Commit: creates and 
             
             
                 
                 
                 
               assigns to client browser the AUTH_genericUserId and 
             
             
                 
                 
                 
               USERSESSION_genericUserId cookies: 
             
             
                 
                 
             
           
        
         
             
               Authentication Cookie 
               Authentication 
               Store Session Cookie 
               Store Session Cookie 
             
             
               Name 
               Cookie Value 
               Name 
               Value 
             
             
                 
             
             
               AUTH_genericUserId 
               genericUserId, 
               USERSESSION_genericUserId 
               genericUserId, 
             
             
                 
               one-way hash( 
                 
               English, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId A, . . . ], 
             
             
                 
               genericUserId + 
                 
               one-way 
             
             
                 
               genericUserId&#39;s 
                 
               hash(encryption key + value 
             
             
                 
               timestamp) 
                 
               part of this cookie) 
             
             
                 
             
           
        
         
             
                 
               2) 
               User Operation: 
               User logins to store A as user ID α. 
             
             
                 
                 
               Manager Operation: 
               Session Initialization: UserId for store A from session is 
             
             
                 
                 
                 
               currently genericUserId; Command Execution: business logic 
             
             
                 
                 
                 
               processing results in change of userId; Session Commit: The 
             
             
                 
                 
                 
               AUTH_α and USERSESSION_α cookies below are written to 
             
             
                 
                 
                 
               the response buffer for assigning to the client browser. The 
             
             
                 
                 
                 
               AUTH_genericUserId and USERSESSION_genericUserId 
             
             
                 
                 
                 
               cookies are deleted. 
             
             
                 
                 
             
           
        
         
             
               Authentication Cookie 
               Authentication 
               Store Session Cookie 
               Store Session Cookie 
             
             
               Name 
               Cookie Value 
               Name 
               Value 
             
             
                 
             
             
               AUTH_α 
               α, 
               USERSESSION_α 
               α, 
             
             
                 
               one-way hash( 
                 
               Spanish, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId A, . . . ], 
             
             
                 
               α + α&#39;s 
                 
               one-way 
             
             
                 
               timestamp) 
                 
               hash(encryption key + value 
             
             
                 
                 
                 
               part of this cookie) 
             
             
                 
             
           
        
         
             
                 
               3) 
               User Operation: 
               User adds items to a shopping cart of Store A. 
             
             
                 
                 
               Manager Operation: 
               Session Initialization: Current User ID for store A from session 
             
             
                 
                 
                 
               data is α; Command Execution: Request processing; Session 
             
             
                 
                 
                 
               Commit: No changes to cookies. 
             
             
                 
               4) 
               User Operation: 
               User navigates to store B&#39;s page which requires a guest user ID: 
             
             
                 
                 
                 
               e.g. 
             
             
                 
                 
                 
               shop.ibm.com/. . . StoreFront?storeId=B&amp;langId=En&amp;curId=US 
             
             
                 
                 
               Manager Operation: 
               Session Initialization: Cannot reuse the userId already in the 
             
             
                 
                 
                 
               session, thus creates a guest user (e.g. user ID 123); Command 
             
             
                 
                 
                 
               Execution: Request processing; Session Commit: Cookies 
             
             
                 
                 
                 
               updated: 
             
             
                 
                 
             
           
        
         
             
               Authentication Cookie 
               Authentication 
               Store Session Cookie 
               Store Session Cookie 
             
             
               Name 
               Cookie Value 
               Name 
               Value 
             
             
                 
             
             
               AUTH_α 
               α, 
               USERSESSION_α 
               α, 
             
             
                 
               one-way hash( 
                 
               Spanish, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId A, . . . ], 
             
             
                 
               α + α&#39;s 
                 
               one-way 
             
             
                 
               timestamp) 
                 
               hash(encryption key + value 
             
             
                 
                 
                 
               part of this cookie) 
             
             
               AUTH_123 
               123, 
               USERSESSION_123 
               123, 
             
             
                 
               one-way hash( 
                 
               English, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId B, . . . ], 
             
             
                 
               123 + 123&#39;s 
                 
               one-way 
             
             
                 
               timestamp) 
                 
               hash(encryption key + value 
             
             
                 
                 
                 
               part of this cookie) 
             
             
                 
             
           
        
         
             
                 
               5) 
               User Operation: 
               User logons to store B as β. 
             
             
                 
                 
               Manager Operation: 
               Session Initialization: The User ID for store B from this session 
             
             
                 
                 
                 
               is currently 123; Command Execution: . . . business logic 
             
             
                 
                 
                 
               processing results in change of identity to β; Session Commit: 
             
             
                 
                 
                 
               AUTH_β and USERSESSION_β cookies are written to the 
             
             
                 
                 
                 
               response buffer and AUTH_123 and USERSESSION_123 
             
             
                 
                 
                 
               cookies are deleted from the client browser. 
             
             
                 
                 
             
           
        
         
             
               Authentication Cookie 
               Authentication 
               Store Session Cookie 
               Store Session Cookie 
             
             
               Name 
               Cookie Value 
               Name 
               Value 
             
             
                 
             
             
               AUTH_α 
               α, 
               USERSESSION_α 
               α, 
             
             
                 
               one-way hash( 
                 
               Spanish, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId A, . . . ], 
             
             
                 
               α + α&#39;s 
                 
               one-way 
             
             
                 
               timestamp) 
                 
               hash(encryption key + value 
             
             
                 
                 
                 
               part of this cookie) 
             
             
               AUTH_β 
               β, 
               USERSESSION_β 
               β, 
             
             
                 
               one-way hash( 
                 
               French, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId B, . . . ], 
             
             
                 
               β + β&#39;s 
                 
               one-way 
             
             
                 
               timestamp) 
                 
               hash(encryption key + value 
             
             
                 
                 
                 
               part of this cookie) 
             
             
                 
             
           
        
         
             
                 
               6) 
               User Operation: 
               User logs off store B. 
             
             
                 
                 
               Manager Operation: 
               Session Initialization: Identity for store B from session data is β; 
             
             
                 
                 
                 
               Command Execution: Request processing results in logoff; 
             
             
                 
                 
                 
               Session Commit: The AUTH_β and USERSESSION_β cookies 
             
             
                 
                 
                 
               are deleted on the client browser, for example, by having 
             
             
                 
                 
                 
               manager write these cookies to the response buffer and setting 
             
             
                 
                 
                 
               the cookie age to zero. Also, the value is set as DEL. 
             
             
                 
                 
             
           
        
         
             
               Authentication Cookie 
               Authentication 
               Store Session Cookie 
               Store Session Cookie 
             
             
               Name 
               Cookie Value 
               Name 
               Value 
             
             
                 
             
             
               AUTH_α 
               α, 
               USERSESSION_α 
               α, 
             
             
                 
               one-way hash( 
                 
               Spanish, US dollars, 
             
             
                 
               encryption key + 
                 
               [storeId A, . . . ], 
             
             
                 
               α + α&#39;s 
                 
               one-way 
             
             
                 
               timestamp) 
                 
               hash(encryption key + value 
             
             
                 
                 
                 
               part of this cookie) 
             
             
                 
             
           
        
       
     
   
   As will be appreciated by those skilled in the art, modifications to the above-described embodiment can be made without departing from the essence of the invention. For example, persons of ordinary skill in the art will appreciate that the generic user type may be adopted for reasons of scalability. Generic users require fewer resources and these may be reused. UserIDs and associated types are persisted by the e-commerce site, for example, by storing to an information retrieval system such as a database table. In the exemplary embodiment, the table stores the user ID along with its type, using R to indicate registered userIDs and using G to represent guest user IDs. However, the generic user ID is hard coded to a specific number. 
   While one (or more) embodiment(s) of this invention has been illustrated in the accompanying drawings and described above, it will be evident to those skilled in the art that changes and modifications may be made therein without departing from the essence of this invention. All such modifications or variations are believed to be within the sphere and scope of the invention as defined by the claims appended hereto. Other modifications will be apparent to those skilled in the art and, therefore, the invention is defined in the claims.