On Tuesdays the USTPO issues new patents. Today's Spotlight Patents concern aspects of conditional access systems and copy protection techniques for video. Assigned to Irdeto (NL), the first patent addresses conditional access techniques. Assigned to Samsung (KR), the second patent address copy protection techniques.
7,403,618, "Conditional access," assigned to Irdeto (NL).
A transmitter provides receivers conditional access to data transmitted via a network. A content encryptor is used to encrypt the data under control of a same authorization key before it is transmitted to all receivers. The transmitter has a storage with a plurality of device keys. A further encryptor is used for producing a key block with a plurality of entries, where each entry is associated with a respective one of the device keys. At least some of the entries contain a representation of the authorization key encrypted with the associated device key. The transmitter transmits the same key block to all receivers.The receiver has a subset of the device keys. A first decryptor is used to retrieve the authorization key by decrypting at least one entry of the key block that is associated with one of the device keys of the receiver. A second decryptor is used for decrypting the data under control of the authorization key.
7,403,617, "System and method for copy protection for digital signals," assigned to Samsung (KR).
Embodiments of the present invention provide for the copy protection of distributed material after conditional access is applied, regardless of where the material is distributed. The solutions described provide the advantage of being sufficiently simple in implementation to qualify as "curb high" solutions. "Curb high" solutions provide a range of security from minimal security to a high level of security while requiring relatively fewer system resources to implement than prior approaches.