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.

Date of Patent:
Feb. 23, 1999

Filed:

Aug. 01, 1995
Applicant:
Inventors:

Kazuo Nakashima, Kawasaki, JP;

Masaru Nakahara, Kawasaki, JP;

Satoshi Itami, Kawasaki, JP;

Kenichi Utsumi, Kawasaki, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
380-4 ; 380 21 ; 380 23 ; 380 25 ; 380 44 ; 380 46 ; 380 49 ; 380 50 ;
Abstract

A CD-ROM stores encrypted software. When a user desires to decrypt and install this software, an approval preparatory key is generated by an installer. This approval preparatory key is generated based on time data. When the user informs a center of this approval preparatory key, the center calculates a difference between this approval preparatory key and a decrypting key and vends this calculated result to a user in the form of an approval key. When the user inputs this approval key to an installer, the installer generates a decrypting key by adding the approval preparatory key to the approval key. The installer decrypts the software by this decrypting key and installs the encrypted software into a personal computer system.


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