Patent application number | Description | Published |
20110308291 | TITANIUM SLAB FOR HOT ROLLING PRODUCED BY ELECTRON-BEAM MELTING FURNACE, PROCESS FOR PRODUCTION THEREOF, AND PROCESS FOR ROLLING TITANIUM SLAB FOR HOT ROLLING - A titanium slab is appropriate for hot rolling, is produced by electron beam melting furnace, has superior linearity so that it can be fed into a hot rolling machine without performing breaking down process or other subsequent correcting process after production, and has good structure having no cracks at the corner parts. A process for production thereof is also provided. The titanium slab is directly produced by a mold of an electron beam melting furnace, and has the deformation of not more than 5 mm for the thickness direction versus the longitudinal direction and deformation of not more than 2.5 mm for the width direction versus the longitudinal direction, both per a length of 1000 mm of the slab. The process for production of this titanium slab for hot rolling has a step of using an electron beam melting furnace in which its rectangular mold has mold walls of a long side and mold walls of a short side, and a step of pouring molten metal from one of the mold walls of a short side. Furthermore, a mold having chamfered parts at the corner parts can be used in the process. | 12-22-2011 |
20110311835 | TITANIUM SLAB FOR HOT ROLLING, AND METHOD OF PRODUCING AND METHOD OF ROLLING THE SAME - The present invention provides a titanium slab for hot rolling which can be fed into a general purpose hot-rolling mill for producing strip coil, without passage through a breakdown process such as blooming or a straightening process, and can further suppress surface defect occurrence of the hot-rolled strip coil, and a method of producing and a method of rolling the same, characterized in that in the cast titanium slab an angle θ formed by the crystal growth direction (solidification direction) from the surface layer toward the interior and a direction parallel to the slab casting direction (longitudinal direction) is 45 to 90°, and moreover, there is a surface layer structure of 10 mm or greater whose θ is 70 to 90°, and further characterized in that a crystal grain layer of 10 mm or greater is formed whose C-axis direction inclination of a titanium a phase is, as viewed from the side of the slab to be hot rolled, in the range of 35 to 90° from the normal direction of the surface to be hot rolled. The titanium slab concerned is produced using an electron beam melting furnace by casting at an extraction rate of 1.0 cm/min or greater. | 12-22-2011 |
20140050318 | RE-ENCRYPTION KEY GENERATOR, RE-ENCRYPTION APPARATUS, AND PROGRAM - A re-encryption key generator according to an embodiment generates a re-encryption key required to re-encrypt, without decrypting, ciphertext data obtained by encrypting plaintext data by means of a first public key of a first user device to obtain re-encrypted text data which can be decrypted by a second private key of a second user device. The first storage device stores a first private key corresponding to the first public key. The second storage device stores a second public key corresponding to the second private key. The re-encryption key generation device generates the re-encryption key based on the first private key, the second public key, and the first random number. | 02-20-2014 |
20140208117 | SERVER APPARATUS AND PROGRAM - A server apparatus according to an embodiment generates a random number on receiving from a user apparatus a notification showing that a re-encryption key should be updated, and calculates re-encryption key data on the basis of the re-encryption key stored and the random number generated. The server apparatus transmits the re-encryption key to the user apparatus and receives, from the user apparatus, the user private key not updated yet and re-encryption key updating data calculated from the re-encryption key data on the basis of the user private key updated. The server apparatus calculates the re-encryption key updated, on the basis of the re-encryption key updating data and the random number, and replaces the re-encryption key stored in the storage device with the updated re-encryption key. | 07-24-2014 |
20150043735 | RE-ENCRYPTED DATA VERIFICATION PROGRAM, RE-ENCRYPTION APPARATUS AND RE-ENCRYPTION SYSTEM - In a decryption apparatus according to an embodiment, a holding device pre-holds a verification formula. A determination device performs a calculation based on the verification formula read from the holding device by substituting, into the verification formula, the part of the re-encrypted data received from a re-encryption apparatus and the public key of a re-encryption key generation apparatus and the private key of the decryption apparatus, to determine whether or not the verification formula holds true. An output device outputs verification success when a result of the determination indicates that the verification formula holds true. | 02-12-2015 |
20150180661 | RE-ENCRYPTION KEY GENERATOR, RE-ENCRYPTION DEVICE, ENCRYPTION DEVICE, DECRYPTION DEVICE, AND PROGRAM - A re-encryption key generator according to an embodiment generates a re-encryption key to obtain re-encrypted data that can be decrypted by a second private key of a second user device by re-encrypting ciphertext obtained by encrypting plaintext by a first public key of a first user device without decryption. The re-encryption key generator stores a first private key corresponding to the first public key. The re-encryption key generator stores a second re-encryption key generation key of the second user device that is different from a second public key corresponding to the second private key. The re-encryption key generator generates the re-encryption key based on the first private key and the second re-encryption key generation key. | 06-25-2015 |
20150200917 | COOPERATION SERVICE PROVIDING SYSTEM AND SERVER APPARATUS - Upon receiving ciphertext data transmitted by each service apparatus, a cooperation apparatus according to an embodiment generates re-encrypted data by performing re-encryption processing for the ciphertext data using a re-encryption key. Each of the service apparatuses transmits, to the cooperation apparatus, a request to acquire user information of a user specified by an ID indicated by the ciphertext data and stored in the other service apparatus, together with the ciphertext data. Upon receiving the re-encrypted data transmitted by the cooperation apparatus, the service apparatus acquires an ID by decrypting the re-encrypted data using a private key, reads out user information, and transmits the user information to the other service apparatus. | 07-16-2015 |
20160119292 | RE-ENCRYPTION SYSTEM, RE-ENCRYPTION APPARATUS, AND PROGRAM - A re-encryption system according to this embodiment includes a file sharing apparatus and a re-encryption apparatus. Upon receiving a file request from the client apparatus, the file sharing apparatus acquires a first encrypted file based on the file request, and transmits a re-encryption request including the first encrypted file to the re-encryption apparatus. The re-encryption apparatus re-encrypts the first encrypted file included in the re-encryption request to the second encrypted file based on the re-encryption key, and transmits the second encrypted file to the file sharing apparatus. The file sharing apparatus transmits the second encrypted file to the client apparatus. The client apparatus obtains the file by decrypting the second encrypted file based on a private key corresponding to the public key of the member. | 04-28-2016 |