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. 06, 2011
Filed:
Jan. 04, 2008
Hideki Saga, Kanagawa, JP;
Tatsuya Hirai, Kanagawa, JP;
Hideki Saga, Kanagawa, JP;
Tatsuya Hirai, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments protect user data in its entirety from unauthorized access when an authorized user does not access a medium for a predetermined length of time by making encryption key data used to encrypt the user data unavailable. In one embodiment, using a magnetic disk in which a data losing time of an encryption key data recording area is shorter than a user data recording area, recording is performed to the magnetic disk while encrypting user data during recording, and encryption key data for use with encryption is recorded in the encryption data recording area. For reproduction of the user data, the encryption key data is read from the encryption key data recording area, and the user data encrypted during the recording is output while being decrypted using an encryption key generated by the encryption key data, and the encryption key data is overwritten on the encryption key data recording area.