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. 20, 1993
Filed:
Nov. 05, 1991
Kenji Okada, Kanagawa, JP;
Fumio Mano, Kanagawa, JP;
Nobuyuki Tokura, Kanagawa, JP;
Kiyomi Kumozaki, Kanagawa, JP;
Noriki Miki, Kanagawa, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
In a secure transmission system in which first and second pieces of communication equipment are interconnected via a transmission line, the first communication equipment has a conversion part for encrypting an information signal to be transmitted, through utilization of a received signal and the second communication equipment has an information memory for storing, as a key information, information to be transmitted to the first communication equipment and an inverse conversion part in which the encrypted signal received from the first communication equipment is decoded using the key information read out of the information memory. As the transmission information signal varies, the key information also varies accordingly. Hence, a highly secure transmission system and secure communication equipment can be realized.