An encryption arrangement for multiple encryption of television programs. A system according to embodiments of the present invention multiple encrypts only a portion of the data required for full presentation of a television program to permit coexistence of multiple conditional access encryption systems associated with multiple manufacturer's set-top boxes within a single system. In one embodiment, only critical packets such as those carrying a payload incorporating packetized elementary stream header information is encrypted. By only encrypting a portion of the program, dramatically less bandwidth is consumed than the alternative of multiple encryption of all program data, thus permitting a larger number of programs to be carried over the same bandwidth while permitting coexistence of multiple conditional access systems in a single cable television system.

Critical packet partial encryption

A method and apparatus for enabling use of multiple digital rights management scenarios (DRM). Unencrypted data representing digital content is examined to identify at least segments of content for encryption (608). The identified segments of content are duplicated (610) and then encrypted using a first encryption method associated with a first DRM to produce first encrypted segments. Duplicates are encrypted using a second encryption method associated with a second DRM to produce second encrypted segments (614). A set of pointers are generated that point to the first and second encrypted segments content (618). A file is then created containing first and second encrypted segments of content (622). A file is then created containing first and second encrypted segments of content, pointers and unencrypted content along with DRM rights data to produce a selectively encrypted multiple DRM enabled file.

Content distribution for multiple digital rights management

A method and apparatus for content substitution, consistent with certain embodiments of the present invention involves receiving data representing content, the data having at least first and second packet identifiers (PIDs) associated with first and second portions of content. The content having the first PID is placed into a data stream. An initiation flag is received indicating initiation of a PID mapping operation. The content having the second PID is then mapped to the first PID and the mapped content is placed into the data stream. A termination flag is received indicating termination of the PID mapping operation at which point the process returns to placing content having the first PID into the data stream. The content substitution process can be used to replace advertisements, provide multiple plots, multiple endings, multiple views as well as other applications. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Content replacement by PID mapping

In accordance with one embodiment, a method for securing control words is provided. The method includes receiving scrambled digital content in a descrambler integrated circuit. The method further includes receiving an encrypted control word in the descrambler integrated circuit, decrypting the encrypted control word using a key stored in a register circuit of the descrambler integrated circuit, and descrambling the scrambled digital content in the descrambler integrated circuit using the decrypted control word.

Method and apparatus for securing control words

According to one embodiment, a method for scrambling and descrambling program data comprises the receipt of a mating key generator message including a manufacturer identifier. The mating key generator message is transmitted to a first remote source identified by the manufacturer identifier. In response, a mating key is received from the first remote source. Then, the mating key is supplied to a second remote source, the mating key being subsequently used to encrypt a service key used for scrambling program data.

Method and apparatus for protecting the transfer of data

The authors describe a bit rate reduction algorithm for use in digital VCRs, based on block scrambling and the two-dimensional adaptive discrete cosine transform. This method satisfies many of the demands unique to digital VCRs. Before the encoding process, the input image is divided into 8*8 pixel blocks and then scrambled on a block-by-block basis to achieve efficient bit distribution in a frame and to simplify buffer control strategy. In addition to block scrambling, a simple yet efficient variable length coding method is proposed. Simulation results are presented. >

B.K. Yoo

Papers

Bit Rate Reduction Algorithm For A Digital VCR