Mitsubishi Electric Assigned Patent

Mitsubishi Electric Corporation, Tokyo, Japan, has been assigned a patent (10,116,442) developed by Mori, Takumi, Kawai, Yutaka, and Matsuda, Nori, Tokyo, Japan, for “data storage apparatus, data updating system, data processing method, and computer readable medium.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A data storage unit, (202) stores encrypted data while remaining in an encrypted state, and stores decryption conditions to define a user attribute of a decryption-permission user who is permitted to decrypt the encrypted data. In a case wherein revocation information to indicate a user attribute of a revoked user who is no longer the decryption-permission user has been added to the decryption condition when update timing arrives, a revocation information removing unit, (206) removes the revocation information from the decryption condition while the encrypted data remains in the encrypted state. Further, the revocation information removing unit, (206) transmits the encrypted data and the decryption conditions from which the revocation information has been removed to a re-encryption apparatus that performs re-encryption in a proxy re-encryption scheme, and receives, from the re-encryption apparatus, the encrypted data that has be re-encrypted in the proxy re-encryption scheme using the decryption condition from which the revocation information has been removed. A refresh processing unit, (205) updates the encrypted data that has been re-encrypted and the decryption condition from which the revocation information has been removed.”

The patent application was filed on February 20, 2015 (15/548,071).