Title:
MPEG受信機/デコーダ及びデータをMPEG受信機/デコーダにダウンロードする方法
Document Type and Number:
Japanese Patent JP4062367
Kind Code:
B2
Abstract:
In a digital satellite television system in which a television receives its signal via a receiver/decoder, such as a set top box, interactive applications can be downloaded and run on the receiver/decoder. The application code is arranged as modules, and the downloading of modules is preceded by searching a directory module within a specified local address. The modules are signed and the directory module is signed and encrypted so that a single encryption applies to all of the modules making up the application. Multiple public encryption keys are stored in ROM in the receiver/decoder, so that applications can be created by different sources, without the sources needing to know each other's private encryption keys. A facility is provided to enable an encryption key to be temporarily stored in RAM in the receiver/decoder, so that a manufacturer of the receiver/decoder can check its functionality. A signature of the directory may be hidden at a variable position in a block of dummy data in the directory module. An application to be downloaded may be checked against an application validation bitmap stored in the receiver/decoder.
Inventors:
Sulphati, Jean-Claude
Meric, Jerome
Meric, Jerome
Application Number:
JP53991598A
Publication Date:
March 19, 2008
Filing Date:
April 25, 1997
Export Citation:
Assignee:
Canal Plus Society Anonymous
International Classes:
G06F9/445; G06F9/06; G06F9/46; G06F9/48; G06F11/00; G06F11/08; G06F11/10; G06F11/26; G06F11/28; G06F12/00; G06F12/02; G06F13/00; G06F13/10; G06F21/10; G06K17/00; G06K19/00; G06K19/07; G06Q20/00; G06T9/00; G07F7/00; G07F7/10; G09C1/00; G11C8/06; G11C16/02; H04B1/713; H04B7/185; H04H20/02; H04H40/00; H04L1/00; H04L9/00; H04L9/10; H04L9/32; H04L12/56; H04L13/08; H04L29/10; H04N5/00; H04N5/222; H04N5/455; H04N7/14; H04N7/16; H04N7/167; H04N7/173; H04N7/26; H04N7/66; H04N17/00; H04N17/04; H04N21/235; H04N21/258; H04N21/435; H04N21/443; H04N21/458; H04N21/462; H04N21/4623; H04N21/4782; H04N21/81; H04N21/84; G06F11/14; H04N5/44; H04N
Domestic Patent References:
| JP8046950A | ||||
| JP8046925A | ||||
| JP8166925A |
Foreign References:
| EP0752786A1 |
Other References:
Macq,B.M and Quisquater J-J., Cryptology for Digital TV Broadcasting,Proceedings of IEEE, 1995年 6月 1日, P.944-957
Attorney, Agent or Firm:
Tadahiko Ito