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: An attack detection device (120) includes an anomalous pattern detection unit (123) to detect whether an anomalous pattern is included in a time-series recognition score that is time-series data generated using a plurality of recognition scores that are calculated respectively using a plurality of pieces of image data captured of a range within an image-capture range at mutually different time points within an image-capture time range, and indicate results of detecting objects respectively in the plurality of pieces of image data. The anomalous pattern is a pattern that occurs when an adversarial sample patch attack has been conducted against at least one of the plurality of pieces of image data.

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 cryptographic system comprising an encryption device to generate a ciphertext; a master re-encryption key generation device to generate a master re-encryption key that cannot decrypt a ciphertext generated by the encryption device, but can generate a re-encryption key for changing an access range for a ciphertext generated by the encryption device; re-encryption device to generate a re-encryption key for re-encrypting a target ciphertext generated by the encryption device, using the master re-encryption key, and re-encrypts the target ciphertext to generate a re-encrypted ciphertext, using the generated re-encryption key; and a decryption device to decrypt at least one of the ciphertext generated by the encryption device and the re-encrypted ciphertext generated by the re-encryption device.

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: A selection unit (312) selects, from among a plurality of one-class classifiers (313) corresponding to mutually different classes, a one-class classifier corresponding to a class into which input data has been classified by multiclass classification on the input data. The selected one-class classifier executes one-class classification on the input data, thereby calculating a score. A determination unit (314) determines whether a result of multiclass classification on the input data is an erroneous result due to an adversarial example attack, on a basis of the calculated score.

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 key acquisition unit (411) acquires a decryption key ski in a pair of a conversion source and a public key pkj in a pair of a conversion target, out of a plurality of pairs of a decryption key and a public key. A conversion key generation unit (412) encrypts the decryption key ski acquired by the key acquisition unit (411) with the public key pkj, so as to generate a conversion key rki?j for converting a ciphertext encrypted with a public key pki in the pair of the conversion source into a converted ciphertext that can be decrypted with a decryption key skj in the pair of the conversion target. An output unit (413) outputs the conversion key rki?j generated by the conversion key generation unit (412).

Abstract: A search device (60) determines whether or not an auxiliary tag AT corresponding to an auxiliary query AQ obtained by conversion of a keyword exists, among auxiliary tags AT stored in an auxiliary tag storage unit (632) and obtained by conversion of a search word. When it is determined that the auxiliary tag AT corresponding to the auxiliary query AQ exists, the search device (60) specifies an encryption tag ET corresponding to a search query SQ being set with attribute information x indicating an attribute of a user, and the keyword, among encryption tags ET stored in an encryption tag storage unit (633) and being set with an access condition v indicating an accessible attribute, and the search word.

Abstract: A key generation device generates a decryption key dkx having a tag-added decryption key and a decryption key adkx. The tag-added decryption key includes a decryption key tdkx in which a key attribute x is set and a tag tg? required to decrypt a ciphertext with the decryption key tdkx. In the decryption key adkx, the key attribute x is set. An encryption device generates an original ciphertext octy in which a ciphertext attribute y corresponding to the key attribute x is set and which can be decrypted with the tag-added decryption key. A re-encryption key generation device encrypts the decryption key tdkx by an attribute-based encryption scheme using a ciphertext attribute y?, so as to generate a re-encryption key rkx,y? which is a key for generating a re-encrypted ciphertext rcty? which can be decrypted with a decryption key adkx? in which a key attribute x? corresponding to the ciphertext attribute y? is set.

Abstract: An encryption device (50) generates a ciphertext. A master re-encryption key generation device (40) generates a master re-encryption key that cannot decrypt a ciphertext generated by the encryption device (50), but can generate a re-encryption key for changing an access range for a ciphertext generated by the encryption device (50). A re-encryption device (60) generates a re-encryption key for re-encrypting a target ciphertext generated by the encryption device (50), using the master re-encryption key, and re-encrypts the target ciphertext to generate a re-encrypted ciphertext, using the generated re-encryption 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 registration terminal registers a set of a key and a ciphertext in which an access range is set and in which the key K is encrypted in a key server, and registers a tag for searching generated from the key and a keyword for searching in a search server. A search terminal acquires a ciphertext in which an access range whose range for permitting access includes an attribute is set, and decrypts the ciphertext with a decryption key in which the attribute is set, so as to generate a key. The search terminal generates a trapdoor for searching from the key and a keyword for searching, and transmits the trapdoor to the search server to acquire data corresponding to the keyword.

Abstract: A search device (300) transmits a search condition to a management device (400) that manages a numerical value which is a number sequence of one or more digits, based on a digit-by-digit correspondence between a number of each digit of the numerical value and a digit representation which is a symbol representing a digit. A grouping unit performs grouping on a plurality of search-target numerical values to be searched for, each of which is a number sequence of one or more digits, on a basis of commonality of the number of digits and commonality of a number sequence from a most significant digit, so as to generate one or more numerical value groups.

Abstract: In an encrypted tag generation device (40), a core tag generation unit (412) encrypts a range condition x{right arrow over (?)} indicating a range to permit searching, with a tag generation key tk, to generate a core tag c{tilde over (?)}x, which is a vector over a basis B. An encrypted tag generation unit (413) generates an encrypted tag cx, w in which a keyword w1 is set, by converting the core tag c{tilde over (?)}x generated by the core tag generation unit (412), by encode information EW1 in which the keyword w1 for searching is encoded.

Abstract: A key generation device generates a decryption key dkx having a tag-added decryption key and a decryption key adkx. The tag-added decryption key includes a decryption key tdkx in which a key attribute x is set and a tag tg? required to decrypt a ciphertext with the decryption key tdkx. In the decryption key adkx, the key attribute x is set. An encryption device generates an original ciphertext octy in which a ciphertext attribute y corresponding to the key attribute x is set and which can be decrypted with the tag-added decryption key. A re-encryption key generation device encrypts the decryption key tdkx by an attribute-based encryption scheme using a ciphertext attribute y?, so as to generate a re-encryption key rkx,y? which is a key for generating a re-encrypted ciphertext rcty? which can be decrypted with a decryption key adkx? in which a key attribute x? corresponding to the ciphertext attribute y? is set.

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.