05392351 is referenced by 205 patents and cites 10 patents.

An electronic data protection system for protecting electronic data from illegal copying by a third party, includes: a storage medium for storing an encrypted electronic data, a medium number and encrypted permission information; a vendor computer having a personal key generating unit for generating a medium key based on the medium number, an electronic data decrypting key, and an encrypting unit for encrypting the electronic data decrypting key based on the medium key to generate the encrypted permission information; and a user computer having a personal key generating unit for generating a medium key based on the medium number, a decrypting unit for decrypting the encrypted permission information based on the medium key to generate the electronic data decrypting key which is the same as the electronic data decrypting key of the vendor computer, and a decrypting unit for decrypting the encrypted electronic data based on the electronic data decrypting key to generate a plain text electronic data.

Title
Electronic data protection system
Application Number
8/31339
Publication Number
5392351
Application Date
March 15, 1993
Publication Date
February 21, 1995
Inventor
Makoto Yoshioka
Kawasaki
JP
Ryota Akiyama
Kawasaki
JP
Takayuki Hasebe
Kawasaki
JP
Agent
Nikaido Marmelstein Murray & Oram
Assignee
Fujitsu
JP
IPC
H04L 9/32
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