Abstract: A system determines whether to grants access to a network server by a user. Initially, a user attempts to gain access to a network server, such as a web server. Prior to granting access to the network server, the network server authenticates the user by sending an authentication request to an authentication server. The authentication server determines whether the user was already authenticated by the authentication server. If the user was already authenticated by the authentication server, then the network server is notified that the user is authenticated. The network server then grants the user access to the network server. If the user was not already authenticated by the authentication server, then login information is retrieved from the user and compared to authentication information maintained by the authentication server. If the retrieved login information matches the authentication information, then the network server is notified that the user is authenticated.

Abstract: A system determines whether to grants access to a network server by a user. Initially, a user attempts to gain access to a network server, such as a web server. Prior to granting access to the network server, the network server authenticates the user by sending an authentication request to an authentication server. The authentication server determines whether the user was already authenticated by the authentication server. If the user was already authenticated by the authentication server, then the network server is notified that the user is authenticated. The network server then grants the user access to the network server. If the user was not already authenticated by the authentication server, then login information is retrieved from the user and compared to authentication information maintained by the authentication server. If the retrieved login information matches the authentication information, then the network server is notified that the user is authenticated.

Abstract: A system for facilitating exchange of user information and opinion using automated collaborative filtering includes memory elements for storing item profiles and user profiles. The data contained in those profiles is used to calculate a number of similarity factors representing how closely the preferences of one user correlate with another. The similarity factors are evaluated to select a set of neighboring users for each user which represents the set of users which most closely correlate with a particular user. The system assigns a weight to each one of the neighboring users. The system uses the ratings given to items by those neighboring users to recommend an item to a user. The system may be distributed, i.e. the system may include a number of nodes connected to a central server. The central server includes a memory element for storing user profile data and the nodes may be the type of system described above.

Abstract: A method for recommending items to users using automated collaborative filtering stores profiles of users relating ratings to items in memory. Profiles of items may also be stored in memory, the item profiles associating users with the rating given to the item by that user or inferred for the user by the system The user profiles include additional information relating to the user or associated with the rating given to an item by the user. Item profiles are retrieved to determine which users have rated a particular item. Profiles of those users are accessed and the ratings are used to calculate similarity factors with respect to other users. The similarity factors, sometimes in connection with confidence factors, are used to select a set of neighboring users. The neighboring users are weighted based on their respective similarity factors, and a rating for an item contained in the domain is predicted. In one embodiment, items in the domain have features.

Abstract: An object for providing isolated, hierarchical data storage can be used in a method for recommending an item to one of a plurality of users. The data object abstracts an associated physical memory element and provides an interface for storing data and retrieving data from the physical memory element. In some embodiments the data object is provided with an indicator for identifying another data object that is used if a memory request is unable to be serviced by the associated physical memory element. In other embodiments this data object can be used to efficiently and transparently store profile data associated with a system for recommending items to users.

Abstract: A system for enabling an information marketplace includes a central server which stores data in a memory element. The data may or may not be encrypted. Regardless of whether the data is encrypted the server may also store a table which associates data elements and nodes with an authorization value. If a node requests data for which the authorization value in the table gives the node authorization to access, the server transmits the data to the node. If the data is encrypted, the server may transmit the encrypted data or it may decrypt the data for the node before transmission. In other embodiments, no table is stored by the server. In these embodiments the data is encrypted using one or more encryption keys. When a node requests data the server transmits the encrypted data to the node. If the node does not have the proper encryption keys, it may request them from the server.