Patent application number | Description | Published |
20090031418 | Computer, method for controlling access to computer resource, and access control program - Valid state judging means judging a valid state of an access permission based on state of an execution environment; an access permission management table specifying an access permission to computer resource based on the valid state by the valid state judging means; and an access control execution environment conducting access control based on the access permission management table are provided. | 01-29-2009 |
20090265539 | Content Distribution system, Terminal, and Server - A terminal writes first encrypted data in which a communication key and an owner ID are encrypted by using a public key into a second recording medium, and this medium is mounted to a communication apparatus so that the first encrypted data are transmitted to a server. The server sends second encrypted data which it acquires by encrypting a content decryption key by using the communication key which the server acquires by decrypting the received first encrypted data by using a secret key to the communication apparatus, and causes the communication apparatus to record them into the second recording medium. The terminal decrypts a content stored in a first recording medium by using the content decryption key which it acquires by decrypting the second encrypted data read from the second recording medium by using the communication key. | 10-22-2009 |
20100058077 | CONFIDENTIAL INFORMATION MEMORY APPARATUS, ERASING METHOD OF CONFIDENTIAL INFORMATION, AND ERASING PROGRAM OF CONFIDENTIAL INFORMATION - A tamper resistant apparatus | 03-04-2010 |
20110016510 | SECRET INFORMATION MANAGEMENT APPARATUS, INFORMATION PROCESSING APPARATUS, AND SECRET INFORMATION MANAGEMENT SYSTEM - Secret key backup is safely implemented even if a role base access structure in which the access structure is specified using roles is used. An all combination generating unit | 01-20-2011 |
20120207299 | DATA PROCESSING DEVICE - A certification device | 08-16-2012 |
20120297201 | CONFIDENTIAL SEARCH SYSTEM AND CRYPTOGRAPHIC PROCESSING SYSTEM - A confidential search that can flexibly control searchable data depending on a role or authority of a user when the data is shared in a group. When the inner product of an attribute vector and a predicate vector is a predetermined value, the confidential search system conducts pairing computation of decrypted data generated based on the attribute vector and a decryption key generated based on the predicate vector, so as to realize confidential search by utilizing an inner-product predicate encryption process that can decrypt the encrypted data. In particular, the confidential search system enables flexible control of searchable data depending on the role or authority of the user, by devising a method of generating the attribute vector and the predicate vector. | 11-22-2012 |
20120324240 | SECURE SEARCH SYSTEM, PUBLIC PARAMETER GENERATION DEVICE, ENCRYPTION DEVICE, USER SECRET KEY GENERATION DEVICE, QUERY ISSUING DEVICE, SEARCH DEVICE, COMPUTER PROGRAM, SECURE SEARCH METHOD, PUBLIC PARAMETER GENERATION METHOD, ENCRYPTION METHOD, USER SECRET KEY GENERATION METHOD, QUERY ISSUING METHOD, AND SEARCH METHOD - In a secure search system to be used by a plurality of users, the size of a ciphertext is reduced and the need to generate a new ciphertext when a new user is added is eliminated. A public parameter generation device | 12-20-2012 |
20130287206 | ENCRYPTION SYSTEM, ENCRYPTION PROCESSING METHOD OF ENCRYPTION SYSTEM, ENCRYPTION DEVICE, ENCRYPTION PROGRAM, DECRYPTION DEVICE, DECRYPTION PROGRAM, SETUP DEVICE, SETUP PROGRAM, KEY GENERATION DEVICE, KEY GENERATION PROGRAM, KEY DELEGATION DEVICE, AND KEY DELEGATION PROGRAM - In a wildcard-applicable anonymous hierarchical identity-based encryption system, it is aimed to make the number of pairing operations a fixed number. A user identifier ID and a pattern P are used. The user identifier ID includes k number of hierarchy identifiers. The pattern P includes either of a hierarchy identifier, a wildcard value and a blank value for each hierarchy. An encryption device | 10-31-2013 |
20130287210 | DATA PROCESSING APPARATUS AND DATA STORAGE APPARATUS - An access terminal apparatus provides a group determination key being a decryption key to a data center apparatus previously, and then transmits grouping information generated from a keyword of storage target data and having been encrypted to the data center apparatus, with encrypted data of the storage target data and tag data of the encrypted data of the storage target data. The data center apparatus stores the encrypted data relating it to the tag data, decrypts a part of the grouping information with the group determination key, derives an index value from a bit value obtained by the decryption, and stores the derived index value and the tag data relating them with each other. | 10-31-2013 |
20130318351 | SIMILARITY DEGREE CALCULATION SYSTEM, SIMILARITY DEGREE CALCULATION APPARATUS, COMPUTER PROGRAM, AND SIMILARITY DEGREE CALCULATION METHOD - Based on an encrypted feature vector (comparison ciphertext) encrypted with a public key of a decryption apparatus and an encrypted feature vector (target ciphertext) encrypted with the public key of the decryption apparatus, and a random number (temporary key) generated by a random number generation unit (temporary key generation unit), an encrypted random similarity degree calculation unit (interim similarity degree ciphertext calculation unit) performs calculation for calculating a similarity degree in a first stage, with two encrypted feature vectors kept encrypted, thereby calculating a second challenge. The decryption apparatus decrypts the second challenge with a secret key sk of the decryption apparatus, and performs calculation for calculating the similarity degree in a second stage with a result of the decryption kept encrypted with the temporary key, thereby calculating a second response. A plaintext similarity degree extraction unit (similarity degree calculation unit) decrypts the second response with the temporary key, thereby calculating a similarity degree. | 11-28-2013 |
20130332729 | SEARCH SYSTEM, SEARCH METHOD OF SEARCH SYSTEM, INFORMATION PROCESSING DEVICE, SEARCH PROGRAM, CORRESPONDING KEYWORD MANAGEMENT DEVICE, AND CORRESPONDING KEYWORD MANAGEMENT PROGRAM - A searchable encryption resistant to frequency analysis. A conversion rule management device generates a conversion rule table associating a search keyword with a conversion keyword group. Based on the conversion rule table, a data registration device generates registration data associating encrypted data with an encrypted keyword, and registers the registration data in a server device. An information processing device obtains from the conversion rule table a conversion keyword group associated with a specified search keyword, generates an encrypted keyword group, and requests a data search by specifying the encrypted keyword group. Using as a search key an encrypted keyword included in the encrypted keyword group, the server device searches for encrypted data associated with the search key, and returns searched encrypted data. The information processing device decrypts the searched encrypted data, and outputs as a search result search data obtained by decryption. | 12-12-2013 |
20140247939 | DATA PROCESSING DEVICE AND DATA PROCESSING METHOD AND PROGRAM - A storage part stores a public key generated based on a doubly homomorphic encryption algorithm and data encrypted by using the public key as a template to be used for authentication. A random number generating part generates a random number using at least a part of the public key in the storage part. A template updating part performs an arithmetic operation using the random number generated by the random number generating part and updates the template. The storage part stores the updated template by overwriting the template before being updated. | 09-04-2014 |
20140298009 | DATA SEARCH DEVICE, DATA SEARCH METHOD, DATA SEARCH PROGRAM, DATA REGISTRATION DEVICE, DATA REGISTRATION METHOD, DATA REGISTRATION PROGRAM, AND INFORMATION PROCESSING DEVICE - A data search server stores a system ciphertext including a data ciphertext and a keyword ciphertext in each category-specific DB unit for each data category, and stores each category-determination secret key being associated with each category-specific DB unit. A search request receiving unit receives from a data search terminal a search request including a search trapdoor and an index tag. A data searching unit searches for a category-determination secret key with which the index tag is decrypted to the same value as a key-determination value. Using the search trapdoor, the data searching unit performs a search of a Public-key Encryption with Keyword Search scheme on system ciphertexts in a category-specific DB unit associated with this category-determination secret key. A search result transmitting unit transmits to the data search terminal a data ciphertext included in a system ciphertext which has been found as a hit in the search. | 10-02-2014 |
20140310521 | ENCRYPTED DATA MANAGEMENT DEVICE, ENCRYPTED DATA MANAGEMENT METHOD, AND ENCRYPTED DATA MANAGEMENT PROGRAM - An invalidation scheme of a secret key is implemented, which is usable for a functional encryption scheme. In a cryptographic processing system | 10-16-2014 |