Protect content from illegal production by proving the existence of a complete dataset

摘要

A number of data items are selected for inclusion in a data set so as to discourage a transmission of the entire set over a limited bandwidth communications path, such as the Internet. Each portion of a data set is bound to the entirety of the data set so that portions of data sets that are independently distributed can be distinguished. In the case of audio recordings, for example, the data set includes an entire album, the individual songs on the album constituting portions of this data set. By binding each song to the album, a compliant player can be configured to refuse to render items in the absence of the complete data set. In this manner, the theft of a song requires a theft of the entire album. An uncompressed digital recording of an entire album consumes hundreds of megabytes of data, and the infeasibility or impracticality of downloading hundreds of megabytes of data is expected to provide sufficient discouragement for the theft of uncompressed content material. In a preferred embodiment, a watermark is created for each section of the data sent that contains an "entirety parameter" associated with the data set. The entirety parameter is a hash value that is based on a random number stored in the watermarks of each section. When presented for rendering, the entirety parameter is read, and the watermarks of a random selection of sections within the data set are compared to this entirety parameter to assure, with statistical certainty, that the entirety of the data set is present.