Patent application number | Description | Published |
20090024852 | GROUP SIGNATURE SYSTEM, METHOD, DEVICE, AND PROGRAM - A signature device | 01-22-2009 |
20090034739 | KEY ISSUING METHOD, GROUP SIGNATURE SYSTEM, INFORMATION PROCESSING APPARATUS, AND PROGRAM - There is provided in accordance with the present invention a key issuing method for being performed by a user apparatus in a group signature system including the user apparatus and an issuer apparatus connected to the user apparatus through a network. The method comprises: reading an issuer public key from the issuer apparatus into a user storage through the network; receiving, from the issuer apparatus through the network, first confidential data including one or plural confidential texts which are produced by confidentializing the issuer public key using element data containing information of an element of a group in the issuer apparatus; performing a second confidential data generating process for generating second confidential data of a confidential text represented by the product of modulo-exponentiated element data corresponding to the confidential texts included in the first confidential data or a confidential text represented by the sum of the element data multiplied by a constant, using the issuer public key and the first confidential data; sending the second confidential data to the issuer apparatus through the network; receiving, from the issuer apparatus through the network, information generated in the issuer apparatus and based on the element data corresponding to the second confidential data; and generating a member public key which is a public key corresponding to the user apparatus and a member secret key which is a secret key corresponding to the user apparatus, using the information based on the element data corresponding to the second confidential data, and writing the member public key and the member secret key into the user storage. | 02-05-2009 |
20090074188 | MEMBER CERTIFICATE ACQUIRING DEVICE, MEMBER CERTIFICATE ISSUING DEVICE, GROUP SIGNING DEVICE, AND GROUP SIGNATURE VERIFYING DEVICE - It is an object of the present invention to enhance the security and reduce the data amount of data to be handled in a group signing system, in which when the group public key which includes: a description for four groups: group 1, group 2, group T, and group E of the same order number; a description of bilinear mapping from group 1 and group 2 to group T; each generator of group 1, group 2, group T, and group E; and a signature public key of a signature scheme using group 1, group 2, and group T, is input, the member secret key including an integer not larger than the order number, member evidence which is a value given by multiplying the generator of group E by the member secret key, and an element of group 1 or group 2 which is a value given by multiplying the generator of the group 1 or the group 2 by the member secret key are sent to the member-certificate issuing device, and thereafter upon receipt of a signature for the member secret key, which is verifiable by the signature public key, from the member-certificate issuing device, the signature is used as the member certificate. | 03-19-2009 |
20090080645 | INTEGRATED SHUFFLE VALIDITY PROVING DEVICE, PROOF INTEGRATING DEVICE, INTEGRATED SHUFFLE VALIDITY VERIFYING DEVICE, AND MIX NET SYSTEM - An integrated shuffle validity proving device ( | 03-26-2009 |
20090287926 | PROVING APPARATUS AND VERIFICATION APPARATUS APPLIED TO DENIABLE ZERO-KNOWLEDGE INTERACTIVE PROOF - The present invention enables deniable zero-knowledge interactive proof to be performed with low amounts of communications and calculations by utilizing a method of a special honest verifier zero-knowledge interactive proof when such method is given. The verification apparatus generates a commitment of a challenge value with respect to a predetermined relationship and transmits the commitment of the challenge value to the proving apparatus, which determines whether or not a required relationship using the commitment of the challenge value holds, and stops its operation if such relationship does not hold. The proving apparatus causes the proof commitment generation apparatus to generate a proof commitment and transmits the proof commitment to the verification apparatus, which transmits a challenge value and a random number to the proving apparatus. The ladder transmits a response to the verification apparatus which determines acceptance or non-acceptance of the proof through communications with the interactive proof verification apparatus. | 11-19-2009 |
20100020977 | KEY GENERATION DEVICE, KEY DERIVATION DEVICE, ENCRYPTION DEVICE, DECRYPTION DEVICE, METHOD AND PROGRAM - A key generation device ( | 01-28-2010 |
20100070768 | KEY EXCHANGE DEVICE, KEY EXCHANGE PROCESSING SYSTEM, KEY EXCHANGE METHOD, AND PROGRAM - A key exchange apparatus according to the present invention includes storage | 03-18-2010 |
20100115285 | MIX-NET SYSTEM - Each participant apparatus ( | 05-06-2010 |
20100132608 | SILICA GLASS CRUCIBLE FOR PULLING UP SILICON SINGLE CRYSTAL AND METHOD FOR MANUFACTURING THEREOF - A silica glass crucible for pulling up a silicon single crystal including a wall part, a corner part and a bottom part is provided with an outer layer formed from an opaque silica glass layer which includes many bubbles, and an inner layer formed from a transparent silica glass layer which substantially does not include bubbles, wherein at least one part of an inner surface of the wall part and the corner part being an uneven surface formed with multiple damaged parts having a depth of 50 μm or more and 450 μm or less, and wherein a region among the inner surface of the bottom part within a certain range from the center of the bottom part being a smooth surface which does is substantially not formed with damage. | 06-03-2010 |
20100170432 | APPARATUS FOR PULLING SILICON SINGLE CRYSTAL - An apparatus for pulling a silicon single crystal, comprising: a crucible that stores a silicon melt; a heater that heats the crucible; a crucible driving unit for rotating and/or lifting up and down the crucible; a chamber that holds the crucible and the heater; and a magnetic field applying unit that is provided outside the chamber and applies a magnetic field to the chamber, wherein the magnetic field applying unit is formed along the outer peripheral surface of the chamber such that substantially concentric circle-shaped equi-strength lines of the magnetic field are formed about a center axis of the crucible. | 07-08-2010 |
20100172496 | KEY GENERATING APPARATUS, ENCRYPTING APPARATUS AND DECRYPTING APPARATUS - A calculation device for calculating two groups G and G | 07-08-2010 |
20100180119 | KEY EXCHANGING APPARATUS - A key exchanging apparatus transmits the contribution data to the plurality of counterpart apparatuses, generates a signer contribution confirmation signature with respect to a contribution data set including all the contribution data received from the plurality of counterpart apparatuses, generates auxiliary data and auxiliary data validity certification sentence from the contribution data set and the contribution random number, transmits the auxiliary data, the auxiliary data validity certification sentence and the contribution confirmation signature to the plurality of counterpart apparatuses, verifies validity of auxiliary data by using the counterpart identifier set, the counterpart public key set, the contribution confirmation signature set including the data received from the plurality of counterpart apparatuses, the auxiliary data set and the auxiliary data validity certification sentence set, and generates a public key from the contribution data set and the auxiliary data received from the plurality of counterpart apparatuses. | 07-15-2010 |
20100199093 | KEY EXCHANGE DEVICE - The present invention includes a section ( | 08-05-2010 |
20110176677 | MULTI-PARTY VARIANCE MULTIPLICATION DEVICE, MULTI-PARTY VARIANCE MULTIPLICATION SYSTEM AND METHOD - A multi-party variance multiplication device includes: an initial setting device which generates a first public key by using an inputted system parameter; a commitment generation device which generates a commitment of a first input value based on the system parameter and a random number; an encryption device which generates an encrypted text of the first input value based on the system parameter, the random number, and the first public key; an authentication device which generates a certificate that authenticates a range of the first input value based on the system parameter, the random number, the first public key, and the second public key already public; a decryption device which generates a decrypted text by decrypting a noisy encrypted text based on the system parameter, the first public key, and a private key; and a noise removal device which generates a product variance by removing a noise from the decrypted text. | 07-21-2011 |
20110179269 | SIGNATURE SYSTEMS - A signature system includes a public key certificate obtainment device | 07-21-2011 |
20110182430 | NAME ENCRYPTION DEVICE, PSEUDONYMIZATION DEVICE, NAME ENCRYPTION METHOD, AND PSEUDONYMIZATION METHOD - Provided is a name encryption device which suppresses leak and facilities the zero-knowledge proof by making the pseudonymization process to be a simple algebraic calculation. The name encryption device converts an encrypted name text into a pseudonym-encrypted text by dispersing the encrypted name text. The encryption device disperses a name into a plurality of name parts to generate a commitment for each of the parts and encrypts disclosure information and each of the name parts by respective public keys. The encryption device outputs the disclosure information relating to the respective commitments and encrypted texts obtained by the respective public keys of the name parts. | 07-28-2011 |
20110202764 | DATA REFERENCE SYSTEM, DATABASE PRESENTATION/DISTRIBUTION SYSTEM, AND DATA REFERENCE METHOD - An element-data generating device encrypts respective vectors each including plural pieces of data, generates a vector including encrypted texts, and outputs such a vector as element data. A database generating system has plural first distributed devices and outputs a sequence of all pieces of element data as a database. A database presentation system has plural second distributed devices, generates, based on a reference item specifying an item to be referred, plural sequences of data to be referred from the database, and performs order shuffling of individual elements of the sequences of the data by all of the second distributed devices so that the order shuffling of the elements of the data sequence is consistent throughout all data sequences. | 08-18-2011 |
20120060028 | SIGNATURE DEVICE, SIGNATURE VERIFICATION DEVICE, ANONYMOUS AUTHETICATION SYSTEM, SIGNING METHOD, SIGNATURE AUTHENTICATION METHOD, AND PROGRAMS THEREFOR | 03-08-2012 |
20120250855 | MIX-NET SYSTEM - Each participant apparatus ( | 10-04-2012 |
20120250868 | MIX-NET SYSTEM - Each participant apparatus ( | 10-04-2012 |
20130073845 | ANONYMOUS CREDENTIAL SYSTEM, USER DEVICE, VERIFICATION DEVICE, ANONYMOUS CREDENTIAL METHOD, AND ANONYMOUS CREDENTIAL PROGRAM - A signature unit, in which a user device generates/transmits digital signature data to an authentication device, includes: a first function, which receives as input a plurality of subsets in which a plurality of characteristics of the users are classified; a second function, which generates a first encrypted text acquired by encrypting a user device public key with an identification device public key; a third function, which generates a second encrypted text, acquired by encrypting characteristic values belonging to a specific subset among the subsets with a characteristic value disclosure device public key; and a fourth function, which employs portions of a group public key and a member certificate to generates a signature of knowledge that denotes that data, of multiplication of a portion of the user device public key and all of the numerical values of a characteristic value certificate corresponding to each of the characteristics, satisfies the specific conditions. | 03-21-2013 |
20130159731 | ENCRYPTED DATABASE SYSTEM, CLIENT TERMINAL, ENCRYPTED DATABASE SERVER, NATURAL JOINING METHOD, AND PROGRAM - A client terminal is provided with: a column encryption unit that, from an encryption key, a table identifier, and a column identifier, generates a column private key, a column public key, and a comparison value, from which the unit generates a concealed comparison value and a ciphertext, thus encryption a particular column; and an encrypted table natural joining request unit that issues a natural joining request text that requests natural joining related to the column encrypted from the encryption key, table identifier, and column identifier. The natural joining request text contains as a table joining key the column public key and column private key that were generated by the encryption key from the table identifier of a first and second tables and the column identifier of the a-th column and b-th column. Then, an encrypted database server executes natural joining using the table joining key, and returns the result. | 06-20-2013 |
20130179684 | ENCRYPTED DATABASE SYSTEM, CLIENT TERMINAL, ENCRYPTED DATABASE SERVER, NATURAL JOINING METHOD, AND PROGRAM - A client terminal is provided with a column encryption unit that, from an encryption key, a table identifier, and a column identifier, generates a column private key, a column public key, and a comparison value, from which the unit generates a concealed comparison value and a ciphertext, encrypting a particular column; and an encrypted table natural joining request unit that issues a natural joining request text that requests natural joining with regards to columns encrypted from the encryption key, the table identifier, and the column identifier. The natural joining request text contains as a table joining key the column private key generated by a group of generating elements and the encryption key from the table identifier of a first and second table and the column identifier of an a-th column and a b-th column. An encrypted database server executes natural joining using the table joining key, and returns the results. | 07-11-2013 |
20130246813 | DATABASE ENCRYPTION SYSTEM, METHOD, AND PROGRAM - A user apparatus connected to database apparatus via network comprises: unit that manages key information in order to encrypt and decrypt; storage unit that stores security configuration information of data and/or metadata; application response unit that determines whether or not encryption is necessary for database operation command, and if encryption is necessary, selects encryption algorithm corresponding to data and/or metadata, performs encryption, and transmits result to database control unit to cause database control unit to execute database operation, if encryption is not necessary, transmits database operation command to database control unit to cause database control unit to execute database operation, and receives processing result transmitted by database control unit, and if decryption or conversion of data and/or metadata of processing result is necessary, performs necessary decryption or conversion, and returns response to database operation command; and security configuration unit that configures security information of data stored in database. | 09-19-2013 |
20130268750 | ENCODED DATABASE MANAGEMENT SYSTEM, CLIENT AND SERVER, NATURAL JOINING METHOD AND PROGRAM - An encrypted database management system includes: a client terminal which includes a column encrypting unit that uses an encrypting key and a group generator to encrypt data of columns indicated by specific labels of externally input tables, and output it, an intra-label projection request unit that generates an intra-label key from encrypting key and label, and outputs it, and an inter-label projection request unit that generates an inter-label projection key from encrypted key, label, and intra-label key; and a database server which includes an intra-label projection unit that generates an intra-label comparison value by the action of label and intra-label key on data of columns of specific labels of encrypted tables, an inter-label projection unit that generates an inter-label comparison value by the action of the inter-label projection key on intra-label comparison value, and an encrypted table natural join unit that conducts natural joining using intra-label comparison value. | 10-10-2013 |
20140133651 | ENCRYPTION DEVICE, CIPHER-TEXT COMPARISON SYSTEM, CIPHER-TEXT COMPARISON METHOD, AND CIPHER-TEXT COMPARISON PROGRAM - An encryption device calculates a derived key by taking a document as a numerical value and corresponding identifier as input values and generates a cipher-text-by-identifier acquired by encrypting the document through a calculation taking the documents as input values, and a comparison unit generates relative values used for a greater-than-and-less-than comparison assessment between the plain text and another plain text through a calculation using a second hash function taking the derived key and plain text as input values; generates a relative value cipher-text through a calculation taking the derived key, the identifier, and the relative value as input values; generates a character string constituted with the cipher-text-by-identifier and the relative value cipher-text as a cipher-text; restores the relative values corresponding to the different cipher-texts through calculations using the second hash function; and performs a greater-than-and-less-than assessment on the encrypted different plain texts through a greater-than-and-less-than comparison on the relative values. | 05-15-2014 |
20140143549 | INFORMATION PROCESSING APPARATUS, INFORMATION PROCESSING METHOD, AND PROGRAM - An information processing apparatus includes: a storage unit that stores a tree structure formed by nodes, each of which is stores identification information identifying a document; and a registration unit that registers documents in the storage unit. The registration unit receives a document including identification information identifying the document and a word set and a key, registers the identification information in a leaf node in the tree structure, and calculates a secure index corresponding to identification information registered in each node from a root node to the leaf node in the tree structure based on the word set and the key. In addition, the registration unit generates a value calculated by adding the calculated secure index as a search index for the document and stores a value calculated by adding a search index generated for each of a plurality of received documents as a search index for the plurality of documents in the storage unit. | 05-22-2014 |
20150033032 | ENCRYPTED DATABASE SYSTEM, CLIENT TERMINAL, DATABASE SERVER, DATA LINKING METHOD AND PROGRAM - An encrypted database system or the like, which make it possible to perform linking between a plurality of tables without decrypting them and further to reduce a risk of the data correlation leaking out, is provided. A client terminal ( | 01-29-2015 |