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:
Sep. 12, 2000
Filed:
Mar. 30, 1998
Eiji Okamoto, Kanazawa-shi, JP;
Masahiro Mambo, Sendai-shi, JP;
Seiichi Domyo, Fujisawa, JP;
Hiroyoshi Tsuchiya, Yokohama, JP;
Tooru Kawai, Yokohama, JP;
Kazuo Takaragi, Ebina, JP;
Naoya Torii, Kawasaki, JP;
Takeshi Tanida, Kanazawa, JP;
Abstract
When a secret is encrypted and stored, it is necessary to provide a countermeasure for the situation where a key is lost (key recovery system). In the present invention, a key recovery system for an enveloped data format in which a common key is used to encrypt a plaintext (secret) and a user's public key is used to encrypt the common key and attached to an encrypted text is provided. In the present invention, only the common key is decrypted to recover the secret without reconstruction of split secret keys kept in a plurality of key storage apparatuses.