Abstract: A measuring device has a consumption measurer to measure a consumption of at least one target equipment at every unit time within a predetermined measurement area, a consumption storage to store the measured consumption, a secret key storage to store a secret key shared with a key management device, an encryption key updater to update an encryption key at every predetermined period based on the secret key and time information, an encryption key storage to store the encryption key, an encryptor to generate encrypted data by encrypting the consumption using the encryption key stored in the encryption key storage, an encrypted data storage to store the encrypted data, and a communication controller to control transmission of the encrypted data, which is stored in the encrypted data storage, to a total consumption detecting device.

Abstract: According to an embodiment, a data generation apparatus includes a first generator, a first determination unit, an acquisition unit, a second generator, and a storage controller. The first generator generates first data unique to an apparatus. The first determination unit determines whether acquisition of second data is necessary according to a predetermined condition. The acquisition unit acquires the second data from an outside of the apparatus when it is determined that acquisition of the second data is necessary. The second generator generates third data by using the first data and the second data. The storage controller stores, into a storage, the second data that has been used for generation of the third data. When it is determined that acquisition of the second data is not necessary, the second generator generates the third data by using the first data and the second data stored in the storage.

Abstract: According to an embodiment, an encryption device performs encryption processing using an encryption key and calculates encrypted data from plain data. The encryption device includes: a register; an input unit configured to receive plain data; a first partial encryption unit configured to calculate first intermediate data from the plain data; a second partial encryption unit configured to calculate (i+1)-th intermediate data based on i-th intermediate data and the encryption key; a first transform unit configured to: transform j-th intermediate data into j-th transformed data; and store the j-th transformed data in the register; and a second transform unit configured to transform the j-th transformed data into the j-th intermediate data; a third partial encryption unit configured to calculate encrypted data from the N-th intermediate data. The second partial encryption unit is configured to repeat processing to calculate (j+1)-th intermediate data while j is equal to from 1 to N?1.

Abstract: According to an embodiment, a data generating device includes a first generator, an obtainer, a second generator, a verifier, and an operation selector. The first generator generates device-specific first data. The obtainer obtains second data from outside of the data generating device. The second generator generates third data based on the first data and the second data. The verifier verifies correctness of the third data. When the third data is determined to be incorrect, the operation selector selects at least one of regenerating the first data, re-obtaining the second data, and disabling the data generating device according to a predetermined selection rule.

Abstract: According to an embodiment, a data converting device is connected to a power meter configured to add up power consumptions of electrical equipment. The device includes a receiving unit configured to receive power consumptions per predetermined unit time added up by the power meter; and a calculating unit configured to calculate a second sequence to be stored as added up power consumptions in a storage unit from a first sequence containing the power consumptions per unit time received by the receiving unit in time series by using a conversion rule for converting a value of a second element in the second sequence based on a value of a first element in the first sequence. The second sequence has no privacy information and, the second sequence can be used for calculating a total value of the first sequence.

Abstract: According to an embodiment, a data management device includes a receiver; a first calculator; a second calculator; and a transmitter. The receiver is configured to receive at least one piece of encrypted data obtained by encrypting a piece of data and at least one message authentication code for the piece of encrypted data. The first calculator is configured to aggregate pieces of encrypted data received to calculate aggregated encrypted data corresponding to a sum of the pieces of data encrypted. The second calculator is configured to sum up message authentication codes received to calculate a total value of the message authentication codes for the aggregated encrypted data. The transmitter is configured to transmit the aggregated encrypted data and the total value of the message authentication codes.

Abstract: An example information processing device includes first and second receiving units, a deciding unit, and first and second transmitting units. The first receiving unit receives adjustment limit information from a plurality of first external devices. The deciding unit determines adjustment rules on the basis of the adjustment limit information. The first transmitting unit transmits the adjustment rules to second and third external devices. The second receiving unit receives determination information from a fourth external device. The second transmitting unit transmits the adjustment rules to the first external devices when integrated schedule information satisfies a condition. When the integrated schedule information does not satisfy the condition, the deciding unit changes the adjustment rules. When the deciding unit has changed the adjustment rules, the first transmitting unit transmits new adjustment rules to the second and third external devices.

Abstract: According to an embodiment, a data management apparatus includes a first receiver, a generator, a second receiver, a convertor, and a transmitter. The first receiver is configured to receive first values from at least one power meter, the first values being acquired by encrypting power usage amounts collected by the at least one power meter using the corresponding first secret key. The generator is configured to generate a second value by summing the first values. The second receiver is configured to receive a conversion key from a key management server. The conversion key is generated by using the first secret key and the second secret key. The convertor is configured to convert the second value into a third value by using the conversion key. The transmitter is configured to transmit the third value to an application server.

Abstract: According to one embodiment, an information processing apparatus, which is connected to an external apparatus, includes a device key storage unit, a creating unit, a calculating unit, a communication unit, and a key calculating unit. The device key storage unit stores therein a device key. The creating unit creates a media key from the device key and a media key block. The calculating unit calculates first output information on the basis of first inherent information inherent to the information processing apparatus and public information. The communication unit transmits the first output information to the external apparatus and receives second output information calculated by the external apparatus from the external apparatus. The key calculating unit calculates a shared key shared between the information processing apparatus and the external apparatus on the basis of the media key, the first inherent information, and the second output information.

Abstract: In a symmetric encryption apparatus according to an embodiment, a storage unit stores a symmetric key formed from a plurality of elements of a first polynomial ring. A plaintext acceptance unit accepts input of plaintext information. A plaintext polynomial generation unit generates a plaintext polynomial by embedding the plaintext information whose input has been accepted in at least one of terms of a polynomial in a subspace of the first polynomial ring. A mask polynomial generation unit generates a mask polynomial having the symmetric key as a solution based on a second commutative ring defined over the first polynomial ring. An encryption unit generates a ciphertext using the plaintext polynomial and the mask polynomial.

Abstract: The debugging unit writes a public key of the key issuing server and an initializing program given from outside, to the storage unit. The instruction executing unit reads and executes the initializing program stored in the storage unit. The debug disabling unit disables the debugging unit. The public-key encrypting unit encrypts the random number by the public key in the storage unit, the random number generated by the random number generating unit after the debugging unit is disabled. The transmitting unit transmits the encrypted random number to the key issuing server. The receiving unit receives an individual key encrypted by the random number from the key issuing server. The individual-key writing unit decrypts the encrypted individual key by the random number to obtain the individual key and write the individual key to the storage unit.

Abstract: According to one embodiment, an information processing apparatus, which is connected to an external apparatus, includes a device key storage unit, a creating unit, a calculating unit, a communication unit, and a key calculating unit. The device key storage unit stores therein a device key. The creating unit creates a media key from the device key and a media key block. The calculating unit calculates first output information on the basis of first inherent information inherent to the information processing apparatus and public information. The communication unit transmits the first output information to the external apparatus and receives second output information calculated by the external apparatus from the external apparatus. The key calculating unit calculates a shared key shared between the information processing apparatus and the external apparatus on the basis of the media key, the first inherent information, and the second output information.

Abstract: According to an embodiment, an information processing device is connected to a management apparatus via a network. The device includes a receiver, an acquisition unit, an MKB processor, and an authentication unit. The receiver is configured to receive communication information. The acquisition unit is configured to acquire a media key block from the management apparatus, in response to receipt of the communication information from a first external device not belonging to a group previously classified on a management unit basis by the management apparatus, the first external device and the information processing device being enabled to derive a first group key based on the media key block. The MKB processor is configured to generate the group key from a device key of the information processing device and the media key block. The authentication unit is configured to perform encrypted communication with the external device based on an authentication method using the group key.

Abstract: According to an embodiment, a generating device includes a first key generator, a second key generator, an output unit, and an update unit. The first key generator is configured to generate a first key that is a sequence of bits according to a first key rule on the basis of a random number. The second key generator is configured to generate multiple second keys that are sequences of bits partially having correlation with one another according to a second key rule on the basis of the first key. The output unit is configured to output the first key and at least one of the second keys. The update unit is configured to generate update information for updating a second key by updating a partial sequence of the second key, the partial sequence having no correlation with the other second keys not to be updated.

Abstract: An arithmetic device includes an input unit inputting data that are elements of a group; a converting unit is configured, when the input data are in a second representation, to convert the input data into a first representation and to perform arithmetic operation on the converted first representation using an operand in the first representation in which at least one subcomponent is a zero element to convert the converted first representation into first converted data expressed in the first representation, and when the input data are in the first representation, to perform arithmetic operation on the input data using the operand in the first representation in which at least one subcomponent is a zero element to convert the input data into second converted data expressed in the first representation; and an operating unit that performs arithmetic processing on the first or the second converted data using secret information.

Abstract: According to an embodiment, a signature generating apparatus includes a generator and an updater. The generator is configured to generate a data sequence including a predetermined number of pieces of first tentative data, and a tentative signature corresponding to the data sequence. The updater is configured to update the tentative signature by replacing the piece of first tentative data with a piece of first actual data, and generate a signature corresponding to a data sequence including the pieces of first actual data by replacing all of the pieces of first tentative data with the respective pieces of first actual data.

Abstract: According to one embodiment, a first shift amount calculation unit counts the number of continuous zeros from a less significant bit toward a more significant bit of an intermediate result of a computation of Montgomery multiplication result z and calculates a first shift amount. A second shift amount calculation unit counts the number of continuous zeros from a less significant bit toward a more significant bit of redundant-binary-represented integer x and calculates a second shift amount. An addition/subtraction unit calculates the intermediate result by adding/subtracting, with respect to the intermediate result which has been bit-shifted by the first shift amount, the integer p, and the integer y which has been bit-shifted by the second shift amount. An output unit outputs, as the Montgomery multiplication result z, the intermediate result when the sum of the first shift amounts is equal to the number of bits of the integer p.

Abstract: According to an embodiment, a data management device includes a receiver; a first calculator; a second calculator; and a transmitter. The receiver is configured to receive at least one piece of encrypted data obtained by encrypting a piece of data and at least one message authentication code for the piece of encrypted data. The first calculator is configured to aggregate pieces of encrypted data received to calculate aggregated encrypted data corresponding to a sum of the pieces of data encrypted. The second calculator is configured to sum up message authentication codes received to calculate a total value of the message authentication codes for the aggregated encrypted data. The transmitter is configured to transmit the aggregated encrypted data and the total value of the message authentication codes.

Abstract: A measuring device has a consumption measurer to measure a consumption of at least one target equipment at every unit time within a predetermined measurement area, a consumption storage to store the measured consumption, a secret key storage to store a secret key shared with a key management device, an encryption key updater to update an encryption key at every predetermined period based on the secret key and time information, an encryption key storage to store the encryption key, an encryptor to generate encrypted data by encrypting the consumption using the encryption key stored in the encryption key storage, an encrypted data storage to store the encrypted data, and a communication controller to control transmission of the encrypted data, which is stored in the encrypted data storage, to a total consumption detecting device.

Abstract: According to an embodiment, a generating device includes a first key generator, a second key generator, and an output unit. The first key generator is configured to generate a first key according to a first key rule in which the first key is generated from a random number, the first key being a bit sequence. The second key generator is configured to generate a plurality of second keys according to a second key rule in which the second keys are generated from the first key, the second keys being bit sequences partly correlated to one another. The output unit is configured to output the first key and at least one of the second keys.