Abstract: The secure join system includes the first and second information-processing-apparatuses respectively holding first and second data. The second information-processing-apparatus is configured to: create third and fourth vectors in which a hash-value related to a key-value of the first data in a first vector and a ciphertext of the first data corresponding to the key-value in a second vector are rearranged by permutation; and create a fifth vector having a hash-value related to a key-value of the second data. The first information-processing-apparatus is configured to: search for j in which a hash-value of an i-th element of the fifth vector matches a j-th element value of the third vector for each i and create encrypted data in which a ciphertext of a j-th element value of the fourth vector is set when j is found and a ciphertext of a dummy value is set when j is not found.

Abstract: A secure collation system performs secure-data-collation between first and second information processing apparatuses and includes the first and second information processing apparatuses. The second information-processing-apparatus creates, when receiving a first vector having a hash value of a key value of the first information-processing-apparatus as an element, a second vector by adding a dummy hash value to the first vector and rearranging the first vector by random permutation; creates a third vector having, as elements, a hash value of a key value of the second information-processing-apparatus and a hash value of a dummy key value; and transmits the second and third vectors to the first information-processing-apparatus. The first information-processing-apparatus calculates a hash value of an element of the third vector and creates a fourth vector having the hash value as an element; and collates matched values between each element of the third vector and each element of the fourth vector.

Abstract: The secure join system includes the first and second information-processing-apparatuses respectively holding first and second data. The second information-processing-apparatus is configured to: create third and fourth vectors in which a hash-value related to a key-value of the first data in a first vector and a ciphertext of the first data corresponding to the key-value in a second vector are rearranged by permutation; and create a fifth vector having a hash-value related to a key-value of the second data. The first information-processing-apparatus is configured to: search for j in which a hash-value of an i-th element of the fifth vector matches a j-th element value of the third vector for each i and create encrypted data in which a ciphertext of a j-th element value of the fourth vector is set when j is found and a ciphertext of a dummy value is set when j is not found.

Abstract: A secure collation system performs secure-data-collation between first and second information processing apparatuses and includes the first and second information processing apparatuses. The second information-processing-apparatus creates, when receiving a first vector having a hash value of a key value of the first information-processing-apparatus as an element, a second vector by adding a dummy hash value to the first vector and rearranging the first vector by random permutation; creates a third vector having, as elements, a hash value of a key value of the second information-processing-apparatus and a hash value of a dummy key value; and transmits the second and third vectors to the first information-processing-apparatus. The first information-processing-apparatus calculates a hash value of an element of the third vector and creates a fourth vector having the hash value as an element; and collates matched values between each element of the third vector and each element of the fourth vector.

Abstract: A key exchange system, for generating a shared key for performing encrypted communication between multiple communication devices, includes the multiple communication devices. Each of the multiple communication devices includes a memory, and a processor configured to generate a short term private key by using a private key, generate a short term public key on one of asymmetric pairing groups used for the ID based encryption, by using the short term private key, and generate a shared key for performing encrypted communication with another communication device by performing a first pairing operation using a private key generated on another one of the asymmetric pairing groups and a short term public key generated in the other communication device, and performing a second pairing operation using the short term private key of the communication device and public information used in generating a private key of the other communication device.

Abstract: A key exchange system in which a shared key is generated for executing encrypted communication between communication apparatuses according to an authenticated key exchange protocol using ID-based encryption, wherein each communication apparatus includes a memory and a processor configured to generate a short-term private key by using a private key of the communication apparatus; generate a short-term public key of the communication apparatus by using the short-term private key; generate private information on the communication apparatus by using the short-term private key, a short-term public key generated by another communication apparatus, and public information generated by the communication apparatus and said another communication apparatus or public information generated by a key delivering center; and generate the shared key for executing encrypted communication with said another communication apparatus by executing a pairing operation using the private key of the communication apparatus and the private

Abstract: An encryption system according to an embodiment is an encryption system for performing encryption and decryption using functional encryption using a quadratic function having n (where n is a predetermined integer of 2 or more) arguments, which includes a setup unit configured to generate a master secret key of the functional encryption using a master secret key of function concealed inner product functional encryption composed of pairing calculation and a master secret key of multi-input function concealed inner product functional encryption obtained by extending the function concealed inner product functional encryption to multi-inputs, an encryption unit configured to generate n pieces of ciphertext obtained by encrypting n pieces of data using the master secret key of the function concealed inner product functional encryption, the master secret key of the multi-input function concealed inner product functional encryption, and the master secret key of the functional encryption, a key generation unit configu

Abstract: An encryption system for performing encryption and decryption by a multi-input inner product functional encryption having a function hiding property includes a setup unit configured to generate, taking a vector length m and the number of arguments ? of an inner product function as input, a master secret key msk and a public parameter pp by using a setup algorithm of a single-input inner product functional encryption having a predetermined characteristic and having a function hiding property and a key generation algorithm of a common key encryption satisfying a predetermined condition, an encryption unit configured to generate, taking the master secret key msk, the public parameter pp, an index i of the arguments, and a vector x as input, a ciphertext cti corresponding to the index i by using an encryption algorithm of the single-input inner product functional encryption and an encryption algorithm of the common key encryption.

Abstract: An inner-product functional encryption scheme in which the maximum length of a ciphertext and the maximum length of a secret key are not restricted can be constructed. An encryption device (20) generates a ciphertext ctx in which a vector x is encrypted, using encryption setting information that is of a size depending on the size of the vector x and is generated using as input public information of a fixed size. A key generation device (30) generates a secret key sky in which a vector y is set, using key setting information that is of a size depending on the size of the vector y and is generated using as input the public information. A decryption device (40) decrypts the ciphertext ctx with the secret key sky to calculate an inner-product value of the vector x and the vector y.

Abstract: An encryption system includes one or more computers each including a memory and a processor configured to generating a public key and a master private key that are used in attribute-based encryption; using, as inputs, at least the public key and one of an attribute and a policy that is denoted by an arbitrary conditional expression related to the attribute, and generating at least cyphertext in which one of the attribute and the policy is embedded; using the public key, the master private key, and the other of the attribute and the policy as inputs, and generating a private key in which the other of the attribute and the policy is embedded; and using the public key, the cyphertext, and the private key as inputs, and decrypting the cyphertext.

Abstract: A key exchange system in which a shared key is generated for executing encrypted communication between communication apparatuses according to an authenticated key exchange protocol using ID-based encryption, wherein each communication apparatus includes a memory and a processor configured to generate a short-term private key by using a private key of the communication apparatus; generate a short-term public key of the communication apparatus by using the short-term private key; generate private information on the communication apparatus by using the short-term private key, a short-term public key generated by another communication apparatus, and public information generated by the communication apparatus and said another communication apparatus or public information generated by a key delivering center; and generate the shared key for executing encrypted communication with said another communication apparatus by executing a pairing operation using the private key of the communication apparatus and the private

Abstract: A key exchange system, for generating a shared key for performing encrypted communication between multiple communication devices, includes the multiple communication devices. Each of the multiple communication devices includes a memory, and a processor configured to generate a short term private key by using a private key, generate a short term public key on one of asymmetric pairing groups used for the ID based encryption, by using the short term private key, and generate a shared key for performing encrypted communication with another communication device by performing a first pairing operation using a private key generated on another one of the asymmetric pairing groups and a short term public key generated in the other communication device, and performing a second pairing operation using the short term private key of the communication device and public information used in generating a private key of the other communication device.

Abstract: An encryption system for performing encryption and decryption by a multi-input inner product functional encryption having a function hiding property includes a setup unit configured to generate, taking a vector length m and the number of arguments ? of an inner product function as input, a master secret key msk and a public parameter pp by using a setup algorithm of a single-input inner product functional encryption having a predetermined characteristic and having a function hiding property and a key generation algorithm of a common key encryption satisfying a predetermined condition, an encryption unit configured to generate, taking the master secret key msk, the public parameter pp, an index i of the arguments, and a vector x as input, a ciphertext cti corresponding to the index i by using an encryption algorithm of the single-input inner product functional encryption and an encryption algorithm of the common key encryption.

Abstract: An inner-product functional encryption scheme in which the maximum length of a ciphertext and the maximum length of a secret key are not restricted can be constructed. An encryption device (20) generates a ciphertext ctx in which a vector x is encrypted, using encryption setting information that is of a size depending on the size of the vector x and is generated using as input public information of a fixed size. A key generation device (30) generates a secret key sky in which a vector y is set, using key setting information that is of a size depending on the size of the vector y and is generated using as input the public information. A decryption device (40) decrypts the ciphertext ctx with the secret key sky to calculate an inner-product value of the vector x and the vector y.