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:
Dec. 23, 1997
Filed:
Nov. 29, 1995
Youichi Takashima, Kanagawaken, JP;
Shinji Ishii, Kanagawaken, JP;
Kiyoshi Yamanaka, Kanagawaken, JP;
Nippon Telegraph & Telephone Corporation, Tokyo, JP;
Abstract
A digital information protection scheme using an improved security protocol. In a system in which a user makes an access to a digital information provided by an information center by connecting a computer card owned by the user to an information terminal device connected with the information center, a work key for encrypting a desired digital information is delivered from the information center to the computer card through the information terminal device, and the work key is registered in the computer card; the desired digital information encrypted by the work key is delivered from the information center to the information terminal device; and an encrypted digital information delivered from the information center is decrypted at the information terminal device by using the work key registered in the computer card, and a decrypted digital information is provided to the user at the information terminal device.