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. 18, 1989
Filed:
Feb. 05, 1987
Hiroyuki Mizutani, Yokohama, JP;
Takashi Kamitake, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A communications network system is constructed by connecting a plurality of customer terminals to one central terminal via communication lines. Enciphering devices and a deciphering device, such as IC (integrated circuit) cards, are provided for the terminals. In order to achieve a digital signature for a transaction message sent from a customer to the center, the message is enciphered according to a prescribed enciphering algorithm using a key word that can specify the sender and the transaction. At the central terminal the enciphered message is deciphered according to a prescribed deciphering algorithm that is different from the enciphering algorithm using a key word which can specify the sender and the transaction. The key data and encipering and deciphering algorithms are sealed in the enciphering and deciphering devices such that they cannot be accessed from the outside.