Patent application number | Description | Published |
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 |
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 |
20150207782 | KEY GENERATION DEVICE, KEY GENERATION PROGRAM, SECRET SEARCH SYSTEM, AND KEY DISTRIBUTION METHOD - A public parameter PK is key information used in a secret search system having: a transmission device generating and sending an encryption tag which is an encrypted keyword; a server receiving and storing the encryption tag and conducting a secret search in response to a request for the secret search; and a reception device generating a trapdoor which corresponds to a digital signature of the keyword and as well data requesting the secret search, sending the trapdoor to the server, and receiving a search result. The public parameter PK includes a true public parameter PP and a protection key PK′. The transmission device and the reception device require both the true public parameter PP and the protection key PK′; however, the server does not require the protection key PK′. The key generation device generates separately the true public parameter PP and the protection key PK′ included in the public parameter PK. | 07-23-2015 |
20150278553 | DATA DECRYPTION DEVICE, ATTRIBUTE-BASED ENCRYPTION SYSTEM, RANDOM NUMBER ELEMENT REMOVING DEVICE, RANDOMIZED SECRET KEY GENERATION DEVICE, DATA DECRYPTION METHOD, AND DATA DECRYPTION PROGRAM - A device and method enhancing security of encrypted data by dividing a decrypting process of an attribute-based encryption scheme into plural stages. A KEM key partly decrypting part generates an r-KEM key mask value including a random number element, by performing a decrypting process for an encrypted KEM key being a common key encrypted using an attribute conditional expression, using an r-user secret key obtained by including the random number element into a user secret key generated in accordance with the attribute-based encryption scheme. A random number element removal requesting part requests an IC card to remove the random number element from the r-KEM key mask value, and acquires a KEM key mask value from the IC card. A mask removing part generates a KEM key using the KEM key mask value. A data decrypting part decrypts an encrypted data main body into target data using the KEM key. | 10-01-2015 |
20150371062 | SERVER DEVICE, CONCEALED SEARCH PROGRAM, RECORDING MEDIUM, AND CONCEALED SEARCH SYSTEM - A server device | 12-24-2015 |