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:
Mar. 25, 2003
Filed:
Jun. 25, 1999
Masatoshi Furuya, Sagamihara, JP;
Toyohiko Yamauchi, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A common key is shared by a controller and an operating terminal. An interface is displayed for entering control signals, and a user enters a control signal . A next operating rights code is generated ( ) and the common key is used to encrypt a signal that contains the control signal , the next operating rights code , and the current operating rights code ( ). This is then transferred to the controller ( ), and the next operating rights code is stored in the operating terminal ( ). The controller uses the common key to decrypt the transferred encrypted message ( ) and obtains the control signal , the current operating rights code , and the next operating rights code . The current operating rights code is checked to see if it matches an operating rights code registered in the controller ( ). If there is a match, the control signal is sent to the control device ( ). The next operating rights code is registered in the controller ( ). The controller contains a table that includes information about common keys, operating rights codes, and modes. When this system is used to perform remote operations via a network, the signals sent through the network are kept secret from third parties and operations can be performed in an exclusive manner.