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. 16, 1999
Filed:
Apr. 03, 1997
Minoru Maruyama, Kawasaki, JP;
Hiroshi Kanno, Kawasaki, JP;
Shuuji Fujiwara, Kawasaki, JP;
Kunio Watanabe, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
To prevent illegal duplication of an ID containing type mobile unit, and illegal duplication of an IC card for an IC card insertion type mobile unit, in manufacturing a COB device, a public key KE.sub.COB, corresponding to a common secret key KD.sub.COB determined through consultation among communications carriers, is stored into a ROM in an unalterable form. In manufacturing a mobile unit, KE.sub.Cj that corresponds to a secret key KD.sub.Cj uniquely assigned to each communications carrier, is signature-encrypted with KD.sub.COB. The result E(KD.sub.COB, KE.sub.Cj) is entered into a COB device to write in KE.sub.Cj ; the COB device 22 is then assembled, prior to shipment, into the mobile unit into which a mobile unit secret key KD.sub.MSNi and public key KE.sub.MSNi have been stored. In registration of the mobile unit, E(KD.sub.Cj, ID) received from the communications carrier is entered into the COB device 22, thereby writing personal information ID. For a readout, KD.sub.MSNi is input to read out the ID.