US Patent 7139808 Method and apparatus for bandwidth-efficient and storage-efficient backups

A method is presented that includes generating a content identifier for at least one article. The content identifier identifies the article. Also, determining if at least a portion of the at least one article is present on at least one device based on the content identifier. The at least one portion of the at least one article is stored if the at least one portion of the at least one article is determined to be not present on the at least one device. Also presented is a method including requesting at least one article by a content identifier representing the article. The at least one article is determined if it is present on at least one device based on the content identifier. At least one portion of the at least one article is returned if the at least one portion of the at least one article is determined to be present on the at least one device.