Abstract: In a profile data delivery control apparatus, a storage unit stores therein a public key and a private key. A control unit obtains profile data including the identification information of a service provided using a server, and when the profile data satisfies a prescribed validity condition, attaches a signature to the profile data using the private key. The control unit embeds the public key to be used to verify the signature, in a client application that causes a client to perform an authentication process based on the profile data, and delivers the client application with the public key embedded.

Abstract: An information processing terminal generates a shared key by a public key cryptosystem using an identifier. The information processing terminal calculates a first calculation value by using an algorithm that outputs an element on an extension field of a prime field from two points on an additive cyclic group on an elliptic curve that is defined by the prime field. The information processing terminal holds the first calculation value. The information processing terminal calculates a second calculation value from a variable using an identifier of a sharer that shares the shared key, a private key of the information processing terminal, and the algorithm. The information processing terminal generates the shared key by executing a final exponentiation to each of the exponentiation of the first calculation value and the second calculation value.

Abstract: A first device generates first encrypted data from a second public key corresponding to second ID regarding a second device and a first random number and transmits first ID regarding the first device, second ID, and first encrypted data. The second device generates second encrypted data from a first public key corresponding to the first ID and a second random number, generates second verification data by generating a second shared-key candidate from the second random number, the first encrypted data, and a second private key, and transmits the second encrypted data and second verification data. The first device generates first verification data by generating a first shared-key candidate from the first random number, the second encrypted data, and a first private key and transmits the first verification data. The first and second devices examine the second and first verification data by using the first and second shared-key candidates, respectively.

Abstract: A method of processing a ciphertext, the method includes: acquiring a part of a plurality of encrypted elements included in the ciphertext, each of the plurality of encrypted elements being an encrypted element in which values of a plurality of elements in a multidimensional determination target vector are respectively encrypted by homomorphic encryption; decrypting the acquired part of the plurality of encrypted elements; and determining validity of the determination target vector based on a relationship between at least one value obtained by the decrypting and both of 0 and 1.

Abstract: A method according to an embodiment includes transforming registered data on a user, which is encrypted with an encryption algorithm that enables a calculation of a Hamming distance in an encrypted state, such that a calculation result of a Hamming distance between the registered data and verification data that is encrypted with the algorithm includes a Hamming distance between the verification data and the user's registered data and a Hamming distance between the verification data and a random vector generated from the user's registered data; calculating a Hamming distance between the verification data and the registered data; and determining whether the input verification data is false based on a result of comparison of each of the Hamming distance between the verification data and the user's registered data and the Hamming distance between the verification data and the random vector included in the calculated Hamming distance with a threshold.

Abstract: In a profile data delivery control apparatus, a storage unit stores therein a public key and a private key. A control unit obtains profile data including the identification information of a service provided using a server, and when the profile data satisfies a prescribed validity condition, attaches a signature to the profile data using the private key. The control unit embeds the public key to be used to verify the signature, in a client application that causes a client to perform an authentication process based on the profile data, and delivers the client application with the public key embedded.

Abstract: A communication device includes a memory and a processor coupled to the memory and configured to, when a first vibration is detected in the communication device, set a certain state that protects information stored in the memory, and cancel the certain state based on receiving from another communication device a notification indicating that the other communication device detected a second vibration.

Abstract: An information processing terminal generates a shared key by a public key cryptosystem using an identifier. The information processing terminal calculates a first calculation value by using an algorithm that outputs an element on an extension field of a prime field from two points on an additive cyclic group on an elliptic curve that is defined by the prime field. The information processing terminal holds the first calculation value. The information processing terminal calculates a second calculation value from a variable using an identifier of a sharer that shares the shared key, a private key of the information processing terminal, and the algorithm. The information processing terminal generates the shared key by executing a final exponentiation to each of the exponentiation of the first calculation value and the second calculation value.

Abstract: A first device generates first encrypted data from a second public key corresponding to second ID regarding a second device and a first random number and transmits first ID regarding the first device, second ID, and first encrypted data. The second device generates second encrypted data from a first public key corresponding to the first ID and a second random number, generates second verification data by generating a second shared-key candidate from the second random number, the first encrypted data, and a second private key, and transmits the second encrypted data and second verification data. The first device generates first verification data by generating a first shared-key candidate from the first random number, the second encrypted data, and a first private key and transmits the first verification data. The first and second devices examine the second and first verification data by using the first and second shared-key candidates, respectively.

Abstract: A cryptographic processing apparatus that holds a first key, and receives authentication object data upon authentication includes a communication unit and a computing unit. The communication unit communicates with a calculation apparatus and a determination apparatus. In the calculation apparatus, encrypted registration data obtained by encrypting registration data twice, once with the first key and once with a second key, is registered. The registration data is data against which the authentication object data is verified. The determination apparatus uses the second key upon the authentication. When registering the encrypted registration data in the calculation apparatus, the computing unit generates a key different from the first key, generates encrypted data by encrypting the registration data twice, once with the first key and once with the different key, transmits the different key to the determination apparatus, and the encrypted data to the calculation apparatus, through the communication unit.

Abstract: A method of processing a ciphertext, the method includes: acquiring a part of a plurality of encrypted elements included in the ciphertext, each of the plurality of encrypted elements being an encrypted element in which values of a plurality of elements in a multidimensional determination target vector are respectively encrypted by homomorphic encryption; decrypting the acquired part of the plurality of encrypted elements; and determining validity of the determination target vector based on a relationship between at least one value obtained by the decrypting and both of 0 and 1.

Abstract: A node device in a network system includes a memory and a processor. The node device is identified with a first value related to a first element and a second value related to a second element. The memory stores a first key corresponding to the first value, a second key corresponding to the second value, first information on a first range of values and second information on a second range of values, at least one of the first key and the second key being shared by at least three or more node devices in the network system. The processor communicates with one of at least three or more node devices indicated by the first value related to the first element and the second value related to the second element using one of the first key and the second key.

Abstract: An encryption processing method executed by a computer, the method includes converting a first vector using a first polynomial representation to acquire a first polynomial; converting an expression using a second polynomial representation to acquire a second polynomial, the expression being obtained based on a second vector and a random number corresponding to the first vector; converting the random number using at least one of the first polynomial representation and the second polynomial representation to acquire a random number polynomial; encrypting the first polynomial, the second polynomial, and the random polynomial using a homomorphic encryption scheme to acquire the encrypted first polynomial, the encrypted second polynomial, and the encrypted random polynomial; and collating the first vector and the second vector using the encrypted first polynomial, the encrypted second polynomial, and the encrypted random polynomial.

Abstract: A node device includes: a processor configured to: receive a first packet that is transferred from a source to a destination via at least one node device including the node device, the first packet including a counter value regarding a number of transfers of the first packet, and first coding information according to a first key information and contents of the first packet, determine whether to conduct a verifying process on the first packet based on the counter value, verify the first coding information is same as a second coding information, the second coding information being generated according to the contents of the first packet and a second key information stored in the memory, change the counter value in the first packet to an initial value, and transmit the first packet including a changed counter value to the destination or any one of the plurality of node devices.

Abstract: An authentication method executed by a computer includes: receiving input data which is a target of authentication; specifying registration data, from among a plurality of registration data stored in a storage device, having a second feature value within a threshold value relative to a first feature value of the input data, the first feature value representing a distance between the input data and a reference, the second feature value representing another distance between the registration data and the reference, and the threshold value being used when a determination as to whether the authentication has been successfully performed; and executing a process of comparing the registration data with the input data.

Abstract: A method according to an embodiment includes transforming registered data on a user, which is encrypted with an encryption algorithm that enables a calculation of a Hamming distance in an encrypted state, such that a calculation result of a Hamming distance between the registered data and verification data that is encrypted with the algorithm includes a Hamming distance between the verification data and the user and a Hamming distance between the verification data and a random vector generated from user's registered data; calculating a Hamming distance between the verification data and the registered data; and determining whether the input verification data is false based on a result of comparison of each of the Hamming distance between the verification data and the user and the Hamming distance between the verification data and the random vector included in the calculated Hamming distance with a threshold.

Abstract: An authentication device includes: a memory; and a processor coupled to the memory and configured to: when a registration request including authentication information to be used during authentication is received from a terminal device, generate registration information using the authentication information and key information and store the registration information in the memory, and when an authentication request including input information to be handled as the target of the authentication is received from the terminal device, generate a result of the authentication based on the input information, the registration information, and the key information, and transmit the result of the authentication to the terminal device.

Abstract: An encryption processing method executed by a computer, the method includes converting a first vector using a first polynomial representation to acquire a first polynomial; converting an expression using a second polynomial representation to acquire a second polynomial, the expression being obtained based on a second vector and a random number corresponding to the first vector; converting the random number using at least one of the first polynomial representation and the second polynomial representation to acquire a random number polynomial; encrypting the first polynomial, the second polynomial, and the random polynomial using a homomorphic encryption scheme to acquire the encrypted first polynomial, the encrypted second polynomial, and the encrypted random polynomial; and collating the first vector and the second vector using the encrypted first polynomial, the encrypted second polynomial, and the encrypted random polynomial.

Abstract: A cryptographic processing apparatus that holds a first key, and receives authentication object data upon authentication includes a communication unit and a computing unit. The communication unit communicates with a calculation apparatus and a determination apparatus. In the calculation apparatus, encrypted registration data obtained by encrypting registration data twice, once with the first key and once with a second key, is registered. The registration data is data against which the authentication object data is verified. The determination apparatus uses the second key upon the authentication. When registering the encrypted registration data in the calculation apparatus, the computing unit generates a key different from the first key, generates encrypted data by encrypting the registration data twice, once with the first key and once with the different key, transmits the different key to the determination apparatus, and the encrypted data to the calculation apparatus, through the communication unit.

Abstract: A first random number receiver receives a first encrypted random number from a data communication apparatus. A second random number transmitter decrypts the first encrypted random number using a first private key to obtain a first random number, encrypts a second random number into a second encrypted random number using a second public key, and transmits it to the data communication apparatus. A hash value receiver receives a first hash value from the data communication apparatus. A session key generator generates a second hash value from the first random number decrypted with the first private key and the second random number, and generates a session key based on the first random number and the second random number when the first hash value is equal to the second hash value. In such key sharing communication, a data communication apparatus and another data communication apparatus achieve three-way handshake.