Title:
【発明の名称】デコーダを具えたメモリ‐カードを用いた加入テレビシステム
Document Type and Number:
Japanese Patent JP3020603
Kind Code:
B2
Abstract:
PCT No. PCT/CH90/00040 Sec. 371 Date Oct. 19, 1990 Sec. 102(e) Date Oct. 19, 1990 PCT Filed Feb. 21, 1990 PCT Pub. No. WO90/10354 PCT Pub. Date Sep. 7, 1990.According to the invention, on the emitter side, a number generator (10) delivers a random code (XAL) which is sent to the input of a master card (11) which ciphers such code according to a predetermined key (100), the code thus ciphered is broadcast with the video signal, a first device (17) receives, on the one hand, the random code (XA) and, on the other hand, the code ciphered by the master card (11) and effects a predetermined numerical combination of these two codes, such combination forming the initialization word of a pseudo-random generator (12) intended to provide a table of codes for scrambling the video signal and, on the receiver side, the ciphered code received is deciphered by a customer card (13), a second device (18) receives at the inputs, on the one hand, the ciphered code and, on the other hand, the code deciphered (XA) by the customer card (13) and effects a numerical combination of these two codes which is similar to the combination of the first device (17).
Inventors:
Kudelsky, Andre
Application Number:
JP50292790A
Publication Date:
March 15, 2000
Filing Date:
February 21, 1990
Export Citation:
Assignee:
Nagra Plus Society Anonymous
International Classes:
H04N7/167; (IPC1-7): H04N7/167; H04N7/16
Attorney, Agent or Firm:
Ichiro Sugawara