Abstract: The functionality of an ereader module that is displaying an electronic book (“ebook”) is extended. A user identifier specifying a user using a client device executing the ereader module and an ebook identifier specifying the ebook displayed by the ereader module are received from the client device. One or more layers associated with the user are determined. One or more layers associated with the ebook are determined. A list of one or more layers is assembled. The layer list is transmitted to the client device. The client device enables the user to select a layer and use the selected layer to interact with content of the ebook.

Abstract: The functionality of an ereader module that is displaying an electronic book (“ebook”) is extended. A user identifier specifying a user using a client device executing the ereader module and an ebook identifier specifying the ebook displayed by the ereader module are received from the client device. One or more layers associated with the user are determined. One or more layers associated with the ebook are determined. A list of one or more layers is assembled. The layer list is transmitted to the client device. The client device enables the user to select a layer and use the selected layer to interact with content of the ebook.

Abstract: Information about named entities referenced in an electronic book (ebook) is provided to a client device. An ebook identifier identifying the ebook is received from the client device. A set of layers available for use with the ebook is determined. The layers in the set provide information associated with the ebook and a layer in the set provides information associated with named entities referenced in content of the ebook. A content range identifying a range of content of the ebook for which layer information is requested and an identification of one or more of the layers in the set for which layer information is requested is received from the client device. Layer information associated with the ebook content identified by the content range for the identified layers is transmitted to the client device. The transmitted layer information includes information associated with named entities referenced by ebook content.

Abstract: A content server provides a browser of a client with encrypted content and with obfuscated browser-executable code for decrypting and displaying the content within the browser. Both the encrypted content and the obfuscated browser-executable code are generated based at least in part on an identity of the user requesting the content, and thus are different from encrypted content and obfuscated browser-executable code provided to other users. Further, in one embodiment the browser-executable code provided by the server changes periodically, such as weekly, thereby rendering ineffective any malicious software tools that obtain decrypted content by calling expected functions of the code. In one embodiment, the obfuscated browser-executable code for a user is pre-computed before that user makes a request for content.

Abstract: An e-book server creates index information for encrypted e-book content. The index information is used by a reader module to efficiently search the encrypted content. To create the index information, the e-book server identifies logical partitions of an e-book that include phrases, and creates encrypted segments including a portion of the e-book content that is not necessarily aligned with the logical partitions of the e-book. The e-book server then stores index information including a mapping between the encrypted segments and the phrases located in the logical partitions.

Abstract: Information about named entities referenced in an electronic book (ebook) is provided to a client device. An ebook identifier identifying the ebook is received from the client device. A set of layers available for use with the ebook is determined. The layers in the set provide information associated with the ebook and a layer in the set provides information associated with named entities referenced in content of the ebook. A content range identifying a range of content of the ebook for which layer information is requested and an identification of one or more of the layers in the set for which layer information is requested is received from the client device. Layer information associated with the ebook content identified by the content range for the identified layers is transmitted to the client device. The transmitted layer information includes information associated with named entities referenced by ebook content.

Abstract: Methods, systems, and apparatus include computer programs encoded on a computer-readable storage medium, including a method for providing content. Login credentials provided by a user are received when communicating through a first user device, and a temporal identifier is created for the user and provided to the first user device. Prior to expiration of the temporary key, login credentials provided by the user on a second different user device are received. The temporal identifier is re-created for the user and provided to the second different user device. A first request is received from the first or second different user device. The temporal identifier is stored and an identifier associated with the device. A second request is received from the other device. A device identifier for the first and second different user device are linked in association with the temporal identifier. The linking is used to respond to the second request.

Abstract: A content server provides a browser of a client with encrypted content and with obfuscated browser-executable code for decrypting and displaying the content within the browser. Both the encrypted content and the obfuscated browser-executable code are generated based at least in part on an identity of the user requesting the content, and thus are different from encrypted content and obfuscated browser-executable code provided to other users. Further, in one embodiment the browser-executable code provided by the server changes periodically, such as weekly, thereby rendering ineffective any malicious software tools that obtain decrypted content by calling expected functions of the code. In one embodiment, the obfuscated browser-executable code for a user is pre-computed before that user makes a request for content.

Abstract: A user interface (e.g., a browser window) includes a display area for displaying an image (e.g., a book page image). The image can be rescaled based on the dimensions of the display area and other factors. In some implementations, margins in book page images are adjusted to create additional or less display area.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer-readable storage medium, and including a method for providing content. The method comprises receiving a first login associated with a first anonymous identifier and first device, creating an associated first private-public key pair, storing a first private key locally in the first device, and publishing a first public key. The method further comprises receiving a second login from a second different device, creating a second private-public key pair, storing a second private key, publishing the second public key, creating a secret key using the first public key, and associating a second anonymous identifier with the secret key. The method further comprises subsequently receiving a login the first device, creating the secret key using the second public key, associating the first anonymous identifier with the secret key, receiving a request for content from either device, and providing content using the association.

Abstract: Information about named entities referenced in an electronic book (ebook) is provided to a client device. An ebook identifier identifying the ebook is received from the client device. A set of layers available for use with the ebook is determined. The layers in the set provide information associated with the ebook and a layer in the set provides information associated with named entities referenced in content of the ebook. A content range identifying a range of content of the ebook for which layer information is requested and an identification of one or more of the layers in the set for which layer information is requested is received from the client device. Layer information associated with the ebook content identified by the content range for the identified layers is transmitted to the client device. The transmitted layer information includes information associated with named entities referenced by ebook content.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer-readable storage medium, and including a method for providing content. The method comprises receiving a first login associated with a first anonymous identifier and first device, creating an associated first private-public key pair, storing a first private key locally in the first device, and publishing a first public key. The method further comprises receiving a second login from a second different device, creating a second private-public key pair, storing a second private key, publishing the second public key, creating a secret key using the first public key, and associating a second anonymous identifier with the secret key. The method further comprises subsequently receiving a login the first device, creating the secret key using the second public key, associating the first anonymous identifier with the secret key, receiving a request for content from either device, and providing content using the association.

Abstract: The functionality of an ereader module that is displaying an electronic book (“ebook”) is extended. A user identifier specifying a user using a client device executing the ereader module and an ebook identifier specifying the ebook displayed by the ereader module are received from the client device. One or more layers associated with the user are determined. One or more layers associated with the ebook are determined. A list of one or more layers is assembled. The layer list is transmitted to the client device. The client device enables the user to select a layer and use the selected layer to interact with content of the ebook.

Abstract: An e-book server creates index information for encrypted e-book content. The index information is used by a reader module to efficiently search the encrypted content. To create the index information, the e-book server identifies logical partitions of an e-book that include phrases, and creates encrypted segments including a portion of the e-book content that is not necessarily aligned with the logical partitions of the e-book. The e-book server then stores index information including a mapping between the encrypted segments and the phrases located in the logical partitions.

Abstract: Users can access personal content on multiple e-book readers. A personal document received from a user is converted from its original format into a shadow e-book of an e-book format. An e-book record is created for the personal document to store information for creating a seamlessly integrated reading experience of the shadow e-book across different e-book readers (e.g., reading position, notes). When an e-book reader requests for the personal document, the shadow e-book is transmitted to the e-book reader along with information from the e-book record. Subsequently, information is received from the e-book reader to update the e-book record.

Abstract: A user interface (e.g., a browser window) includes a display area for displaying a content reference page. In some implementations, a content reference page is generated that includes information related to content. The content reference page includes sections for presenting keywords found in the content, reviews of the content, portions of content that are of interest to a user (or a class of users) and other useful references, etc.

Abstract: A user interface (e.g., a browser window) includes a display area for displaying a content reference page. In some implementations, a content reference page is generated that includes information related to content. The content reference page includes sections for presenting keywords found in the content, reviews of the content, portions of content that are of interest to a user (or a class of users) and other useful references, etc.

Abstract: A computer-implemented information analysis and display system, called a linguistic filter, and method is provided to dynamically generate and display topics representing the linguistic content of documents in a file system. The documents may be user-selected. Also, the user operates a user computer to select one or more of such dynamically generated and displayed topics, preferably using a graphical user interface. The linguistic filter displays document identifiers corresponding to those documents that are described by one or more of the topics selected by the user. The file system may be local, or remote, or both. A user may select for display only those topics representing the linguistic content of documents that are written in one or more user-selected natural languages. Also, topics of documents written in a natural language may be displayed in relation to such natural language. The linguistic filter displays a graphical user interface including a document window and a topic tree window.