Abstract: Described is a solution for maintaining the security of encrypted data despite a compromised private key by using a re-encryption process that does not require decryption of the encrypted data. The compromised private key is re-encrypted using a new public key as is the encrypted symmetric key which the compromised private key can decrypt. When a decrypted version of the encrypted data is requested, the private key corresponding to the new public key decrypts both the encrypted version of the compromised private key and the re-encrypted version of the symmetric key resulting in the unencrypted compromised private key and the previously encrypted version of the symmetric key, which when decrypted using the compromised private key decrypts the encrypted data. The unencrypted symmetric key can then be encrypted using the new public key any encrypted compromised private key can be deleted.

Abstract: Methods, systems and machine-readable instructions for managing images are described. In one aspect, images are segmented into image clusters. A page layout for a contact sheet comprising thumbnail clusters each comprising thumbnails of the images in respective ones of the image clusters is generated. The page layout divides at least a portion of the contact sheet into regions each containing a respective one of the thumbnail clusters and at least one associated user input field. A description of the page layout is stored on a machine-readable medium.

Abstract: Described is a solution for maintaining the security of encrypted data despite a compromised private key by using a re-encryption process that does not require decryption of the encrypted data. The compromised private key is re-encrypted using a new public key as is the encrypted symmetric key which the compromised private key can decrypt. When a decrypted version of the encrypted data is requested, the private key corresponding to the new public key decrypts both the encrypted version of the compromised private key and the re-encrypted version of the symmetric key resulting in the unencrypted compromised private key and the previously encrypted version of the symmetric key, which when decrypted using the compromised private key decrypts the encrypted data. The unencrypted symmetric key can then be encrypted using the new public key any encrypted compromised private key can be deleted.

Abstract: Techniques for performing an incremental update to a set of hierarchically structured information that do not expose the structure and content of the hierarchically structured information to unauthorized parties. The present techniques include encrypting the hierarchically structured information such that an arrangement of nodes and corresponding data of the hierarchically structured information is not exposed and each node includes a corresponding node identifier that is not encrypted and updating the hierarchically structured information by referring to the nodes using the node identifiers.

Abstract: Techniques for verifying whether an incremental update was correctly applied to a set of hierarchically structured information include determining an overall integrity code for the hierarchically structured information and attaching the overall integrity code to the hierarchically structured information. An incremental update according to the present techniques includes an integrity code that is combined into the overall integrity code attached to the hierarchically structured information when the incremental update is applied to the hierarchically structured information. The integrity code of the incremental update is generated such that when the overall integrity code is recomputed it will match the overall integrity code attached to the hierarchically structured information if the incremental update was correctly applied.

Abstract: A method and apparatus for estimating device availability in a pervasive peer to peer environment is presented. The method and apparatus include a linear estimation approach and a bin estimation approach, where the bin estimation approach may include enhanced bin estimation or adaptive bin estimation. A central node queries available contacted devices and builds a history of times and availability indications for the contacted device, and subsequently computes an availability probability curve based on assumptions regarding the availability indications and the time since the last received availability indication.