Abstract: A search execution device receives a trapdoor generated based on a user secret key in which a search auxiliary key and an attribute of a user are set and a search keyword, together with a key identifier (ID) that identifies the search auxiliary key. The search execution device decrypts an encrypted tag in which an attribute of a user who is allowed retrieval and a search word are set, using the received trapdoor and the search auxiliary key indicated by the received key ID, so as to identify a tag that is retrievable for the attribute set in the user secret key and contains a search word corresponding to the search keyword.

Abstract: A registration device (500) accepts plaintext, attribute information of a user having an authority of referring to the plaintext, and a registration key for use in generating a user key for generating a search query. The registration device generates aggregate information indicating one or more aggregate values, by aggregating a plurality of attribute values included in the attribute information. The registration device generates generalized information indicating a plurality of generalized values for each aggregate value by generalizing each aggregate value included in the aggregate information. The registration device generates ciphertext data including the plaintext encrypted, by using the plaintext, the attribute information, the generalized information, and the registration key. The registration device registers the ciphertext data in a database.

Abstract: A registration device (200) generates an encryption keyword by encrypting a keyword with a registration key, generates an index including the encryption keyword and identification information which identifies a corresponding ciphertext, generates a conversion key from the registration key and a search key, and registers a plurality of ciphertexts, the index, and the conversion key in a server device (400). A search device (300) generates a search query by encrypting a keyword, and transmits the search query to the server device (400).

Abstract: A registration device (400) generates ciphertext data using a new data key, generates an encrypted keyword using a new keyword key, and registers a set of the ciphertext data and the encrypted keyword. A search operation device (500) restores an old data key from the new data key, restores an old keyword key from the new keyword key, and generates a new search query and an old search query, using the new keyword key and the old keyword key, respectively. A data management device (600) finds an encrypted keyword that matches one of the new search query and the old search query, and outputs an encrypted search result including ciphertext data corresponding to the encrypted keyword that has been found. The search operation device decrypts a plaintext from the ciphertext data included in the encrypted search result, using one of the new data key and the old data key.

Abstract: An encryption device (50) generates a ciphertext ct encrypted from information x with using an encryption token etk. A decryption key generation device (60) generates a decryption key dk from a user secret key sk in which a vector y is set, with using a decryption token dtk corresponding to the encryption token etk. A privacy-preserving analysis device (70) decrypts the ciphertext ct generated by the encryption device (50), by means of the decryption key dk generated by the decryption key generation device (60), so as to generate a result of computation over the vector x and the vector y.

Abstract: A registration device (500) accepts plaintext, attribute information of a user having an authority of referring to the plaintext, and a registration key for use in generating a user key for generating a search query. The registration device generates aggregate information indicating one or more aggregate values, by aggregating a plurality of attribute values included in the attribute information. The registration device generates generalized information indicating a plurality of generalized values for each aggregate value by generalizing each aggregate value included in the aggregate information. The registration device generates ciphertext data including the plaintext encrypted, by using the plaintext, the attribute information, the generalized information, and the registration key. The registration device registers the ciphertext data in a database.

Abstract: A searchable encryption system includes a registration device including an index generation unit (624) and an encrypted index generation unit (625). The index generation unit (624) generates a registration keyword index by using a registration keyword, authorized-person attribute information corresponding to an authorized person who has an authority to search for the registration keyword, a user key function to generate a user key corresponding to a searcher, a search query function to generate a search query having the user key incorporated therein, and an index query function to generate an index query having the search query incorporated therein. The encrypted index generation unit (625) generates an encrypted index by encrypting the registration keyword index by using the index disclosure key.

Abstract: A registration apparatus generates a data random number tuple R that is a tuple of random numbers whose quantity is the same as a level quantity L of a hierarchy that a user attribute forms, and that is also a tuple of uniformly random numbers. Also, the registration apparatus accepts a plaintext M and attribute information B.

Abstract: A random-number generation unit generates a plurality of random numbers from a plurality of seeds. A data scrambling unit conceals concealment target data which is a concealment target by using the plurality of random numbers generated by the random-number generation unit. A transmission unit transmits concealed data which is the concealment target data concealed by the data scrambling unit to a data analysis device, and transmits any seed among the plurality of seeds to the data analysis device, after transmission of the concealed data to the data analysis device.

Abstract: A data partition unit partitions character string data D into N pieces of element data w1, w2, . . . , wN from a front to an end of the character string data D. A partial character string generation unit generates a set A={A1, A2, . . . , AN} and an element Ai={(wi), (wiwi+1), . . . , (wiwi+1 . . . wN)} of the set A where i=1, . . . , N, from the element data w1, w2, . . . , wN. A position information assignment unit generates a set B={B1, B2, . . . , BN} and an element Bi={(i, wi, (i, wiwi+1), . . . , (i, wiwi+1 . . . wN)} of the set B by associating each of (wi), (wiwi+1), . . . , (wiwi+1 . . . wN) which are components of the element Ai with position information i. An encryption unit encrypts each of (i, wi), (i, wiwi+1), . . . , (i, wiwi+1 . . . wN) which are components included in the element Bi.

Abstract: An encrypted index bit sequence generation unit generates a bit sequence to be used as an index in searching for encrypted data to be stored in a data center apparatus as an index bit sequence, associating the index bit sequence with the encrypted data. The encrypted index bit sequence generation unit encrypts a plurality of bit values in the index bit sequence, using an index key of a common key scheme. A terminal-side data transmission/reception unit transmits to the data center apparatus, an encrypted index bit sequence and the encrypted data, the encrypted index bit sequence being the index bit sequence after the plurality of bit values is encrypted by the encrypted index bit sequence generation unit.

Abstract: A trapdoor acquisition unit (314) acquires a trapdoor t(s) resulting from converting a search word s by a map sk_U? assigned to an identifier U? among maps sk that differ for each identifier. A search ciphertext generation unit (315) converts the trapdoor t(s) acquired by the trapdoor acquisition unit (314) by a map f_U? assigned to the identifier U? among maps f that differ for each identifier, so as to generate a search ciphertext c(s). A composite map of a map sk and a map f assigned to the same identifier is a map mk common to every identifier.

Abstract: A registration destination determination device (50) determines which data management device, among a plurality of data management devices (20A, 20B), is to manage registration data, such that, with a data type constituting the registration data as a target type, an appearance frequency distribution of values set for the target type of the registration data managed by each of the plurality of data management devices (20A, 20B) is different from an appearance frequency distribution of values set for the target type of the registration data managed by the whole of the plurality of data management devices (20A, 20B).

Abstract: An encryption device (50) generates a ciphertext ct encrypted from information x with using an encryption token etk. A decryption key generation device (60) generates a decryption key dk from a user secret key sk in which a vector y is set, with using a decryption token dtk corresponding to the encryption token etk. A privacy-preserving analysis device (70) decrypts the ciphertext ct generated by the encryption device (50), by means of the decryption key dk generated by the decryption key generation device (60), so as to generate a result of computation over the vector x and the vector y.

Abstract: A registration device (200) generates an encryption keyword by encrypting a keyword with a registration key, generates an index including the encryption keyword and identification information which identifies a corresponding ciphertext, generates a conversion key from the registration key and a search key, and registers a plurality of ciphertexts, the index, and the conversion key in a server device (400). A search device (300) generates a search query by encrypting a keyword, and transmits the search query to the server device (400).

Abstract: A management apparatus (500) stores encrypted tags (C(D)) and encrypted data such that they are associated with each other. When a search apparatus (400) obtains a search keyword (s) for searching for encrypted data stored in the management apparatus (500), the search apparatus (400) calculates deterministic information (t) which is uniquely determined by the search keyword (s), and generates a search query (Q(s)) by performing encryption of a probabilistic encryption scheme on the search keyword (s) using the deterministic information (t). The search apparatus (400) transmits the search query (Q(s)) to the management apparatus (500). When the management apparatus (500) receives the search query (Q(s)) from the search apparatus (400), the management apparatus (500) determines whether the search keyword (s) obtained by decrypting the search query (Q(s)) matches an associated keyword obtained by decrypting an encrypted tag (c) stored in the management apparatus (500).

Abstract: A registration apparatus generates a data random number tuple R that is a tuple of random numbers whose quantity is the same as a level quantity L of a hierarchy that a user attribute forms, and that is also a tuple of uniformly random numbers. Also, the registration apparatus accepts a plaintext M and attribute information B.

Abstract: An encryption device (500) includes an encryption unit (504), a detection element generation unit (505), and a transmission unit (506). The encryption unit (504) encrypts a plain text by using one of a pair of keys to generate an encrypted text into which the plain text has been encrypted and which can be subjected to homomorphic computation. The detection element generation unit (505) generates a detection element E used to detect a change in the encrypted text by using the one key and the encrypted text. The transmission unit (506) transmits the encrypted text and the detection element.

Abstract: In a personal searching-purpose ID (511), a personal encryption ID (512) and encrypted personal information (513) stored in a personal information storage unit (51), a disclosure range of personal information is embedded. Also, in a medical searching-purpose ID and a medical encryption ID stored in a medical data storage unit, a disclosure range of medical data is embedded. A search query generation unit generates a search query Q by encrypting a search anonymous ID subject to searching acquired from a user with attribution information of the user embedded. Then, a searching unit executes confidential searching on the personal searching-purpose ID (511) and a pathological searching-purpose ID (521), using the search query Q. The searching unit outputs a searching result acquired based on the attribution information of the user, the disclosure range of personal information and the disclosure range of medical data.

Abstract: 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.