The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1987
Filed:
Apr. 27, 1983
Eiji Okamoto, Tokyo, JP;
Katsuhiro Nakamura, Tokyo, JP;
NEC Corporation, , JP;
Abstract
An enciphering key distribution system comprises a transmitter having an address generator for generating the addresses of those subscribers to which a first enciphered TV signal is to be distributed. An enciphering generator generates a second enciphering, in response to the individual addresses, on a one-to-one correspondence with the individual subscribers. A multiplier produces a product which is associated with all the subscribers. An adder adds the first enciphered signal to the product. The system also comprises a receiver having a divider for dividing the signal transmitted from the transmitter by one of the second encipherings on a basis which is assigned to the particular subscriber or receiver.