Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Masakatsu Matsuo

Masaaki Kobayashi

Hiroyuki Tanaka

Saburo Toyonaga

Kenjiro Ike

Kouji Mutou

Yasuhiko Nishimuta

Katsunori Kogata

A signature generation device includes a data acquirer acquiring a plurality of mutually related pieces of data including first data and a signature generator generating first signature data for the first data and correlation information based on the first data, the correlation information indicating correlation among the plurality of pieces of data, and a signature key. The signature generation device ensures relevance among the plurality of pieces of data.

Signature generation device, signature verification device, signature generation method, and signature verification method

An authentication system includes a terminal having a transmitter, a processor, and a memory, and a server having a receiver, a processor and a memory. The terminal transmits request information to the server. The terminal acquires time information, generates a first one-time password at a pre-determined cycle by using the time information within the terminal, and generates encryption information which is acquired by encrypting the request information using the first one-time password as a key, the encryption information being transmitted from the terminal to the server. The server acquires time information within the server, generates a second one-time password at the pre-determined cycle as the cycle within the terminal by using the time information within the server, generates reference information which is acquired by decoding the encryption information using the second one-time password as a key, and compares the request information with the reference information.

Authentication system and authentication method

A resolution converter converts input image data to N types (N is a plural number) of image data having resolutions different with each other. A secret sharing unit performs secret sharing schemes so that the plurality of pieces of image data are respectively divided into n pieces (n is an integer equal to or more than N+1 and the same value in all of image data) of distributed data and the distributed data is reconstructed to original image data using k pieces (k is an integer equal to or more than 2 and equal to or less than n and different value for each piece of image data) among n pieces. A data combination unit generates n pieces of combination data by combining distributed data selected one by one so as not to overlap with each of resolutions and stores each piece of the combination data in different storages. As more pieces of distributed data are gathered, image data with higher resolutions can be reproduced and security for copyright, privacy, or the like can be secured in each piece of distributed data.

Management device and image processing system

Provided is a terminal authentication system including a client terminal and a server device. The client terminal transmits first information based on secret information different for each client terminal and a client certificate including a hash value of the secret information which is derived from the secret information, to a server device. The server device receives the first information and the client certificate, derives a hash value from the secret information based on the first information using a unidirectional function, and authenticates the client terminal on the basis of the derived hash value and the hash value of the secret information which is included in the client certificate.

Terminal authentication system, server device, and terminal authentication method

A communication system includes a first communication apparatus and a second communication apparatus. The first communication apparatus includes a partial image data generation unit, configured to generate partial image data which is obtained by extracting a partial component from image data, and a transmission unit, configured to transmit the partial image data generated by the partial image data generation unit to the second communication apparatus. The second communication apparatus includes a reception unit, configured to receive the partial image data transmitted by the transmission unit of the first communication apparatus.

Communication system, communication apparatus and communication method

Provided is an authentication system in which a client terminal that receives input of request information is connected to a server that executes a process with regard to the request information. The client terminal includes: a first authentication information generation unit that generates first authentication information based on information which is shared with the server; an encryption unit that generates encryption information; and a transmission unit that transmits the request information and encryption information to the server. The server includes: a reception unit that receives the request information and encryption information; a second authentication information generation unit that generates second authentication information; a decoding unit that generates reference information which is acquired by decoding the encryption information using the same common key method as in the client terminal while using the second authentication information as a key; and an authentication unit that compares the request information with the reference information.

Provided is a signature verification system including a communication device and a verification device. The communication device and the verification device are connected to each other through a network. The communication device derives a first hash value from a first random number, derives a second hash value from data including electronic data and a certificate of the communication device which includes the first hash value and a public key of the communication device, using a unidirectional function, generates a signature using a secret key of the communication device with respect to the second hash value, and transmits the electronic data, the certificate, and the signature to the verification device. The verification device receives the electronic data, the certificate, and the signature, authenticates the communication device using the first hash value included in the certificate, derives the second hash value from the data including the electronic data and the certificate using a unidirectional function, and verifies the signature using the public key of the communication device and the derived second hash value which are included in the certificate.

Signature verification using unidirectional function

A secret sharing apparatus generates, from secret data, a plurality of pieces of shared data from which the secret data is able to be restored. The secret data includes a plurality of pieces of divided data which does not include a random number. The secret sharing apparatus includes a shared data generating section which performs an XOR operation between the pieces of divided data and generates the plurality of pieces of shared data which includes the result of the XOR operation between the pieces of divided data.

Secret sharing apparatus and secret sharing method that restores secret data from at least two of generated shared data

A communication system includes a first communication device, a second communication device, and a key management apparatus. The second communication device generates a random number, generates encrypted data using an encryption key, encrypts the random number, generates key information data, and transmits the key information data, identification information of the second communication device, and the encrypted data to the first communication device. The first communication device receives the key information data, the identification information, and the encrypted data, transmits the key information data and the identification information to the key management apparatus, receives the encryption key from the key management device, decodes the encrypted data and obtains the predetermined data using the received encryption key. The key management apparatus receives the key information data and the identification information, decodes the key information data, acquires the random number, and transmits the encryption key to the first communication device.

Communication system, communication device, key management apparatus, and communication method

Provided is a certificate issuing system including a client terminal and a server device. The client terminal derives a first hash value from a first random number using a unidirectional function, generates a secret key and a public key of the client terminal, and transmits the first hash value and the public key of the client terminal to the server device. The server device receives the first hash value and the public key of the client terminal from the client terminal, stores the first hash value, authenticates the client terminal on the basis of the stored first hash value and the derived first hash value, generates a client certificate on the basis of the public key of the client terminal and a secret key of the server device when the authentication succeeds, and transmits the client certificate to the client terminal.

Certificate issuing system, client terminal, server device, certificate acquisition method, and certificate issuing method

Processing for generating a plurality of pieces of distributed data from original data or processing for restoring original data from a plurality of pieces of distributed data is performed safely and quickly. A distribution and restoration apparatusgenerates a plurality of pieces of distributed data SDto SDby dividing original data OD into a plurality of divided blocks DBto DBand performing an operation of exclusive OR using divided blocks of different combinations. A combination including divided blocks used in common in a plurality of pieces of distributed data and a combination including divided blocks used only in specific distributed data are present in combinations of divided blocks in each piece of distributed data. Therefore, the distribution and restoration apparatuscan generate a plurality of pieces of safe distributed data having high information entropy at high speed.

Distribution apparatus, restoration apparatus, distribution method, restoration method, and distribution and restoration system

In a secret sharing process based on an improved threshold scheme, secret data is shared as shared data parts equal to or greater than a threshold value in number such that the secret data cannot be reconstructed from shared data parts less than the threshold value in number. Each of the shared data pieces is created essentially from a different combination of the secret data pieces and the data pieces for secret sharing computation. The secret sharing process allows an algorithm desired by the user to be freely incorporated, and can prevent the secret data to be easily reconstructed even when more shared data parts than the threshold value are acquired by a third party.

Secret sharing method and system

A communication apparatus communicates with another communication apparatus by using a first key. The communication apparatus includes a processing unit that conducts a handshake process for a key exchange with the another communication apparatus and a key encryption unit that conducts an encryption process by using a second key. The processing unit conducts a first handshake process with the another communication apparatus without exchanging information on the first key while serving as a reception side of key information. Then, the processing unit conducts a second handshake process with the another communication apparatus to transmit the information on the first key encrypted by the key encryption unit by using the second key to the another communication apparatus.

Communication apparatus and communication system

In order to protect SSL encrypted communication from MITM attacks, a server certificate is used in the communication. However, operation of the server certificate is not simple, and the certificate is not sufficient to protect the communication from the MITM attacks. In SSL encrypted communication in which a password is shared between a client and a server, the client encrypts random number data and a password by means of a public key, determines a value by processing encrypted data by means of encrypted password data, and transfers the thus-determined value to the server. The server eliminates the password encrypted data from the value and back calculates the random number data, which are then decrypted, to thus acquire the random number data generated by the client. A hash value of the random number data is submitted to the client.

Encryption apparatus, decryption apparatus, encryption method, decryption method, and encryption/decryption system

A decrypting apparatus for decrypting cryptography data included in a packet includes a receiver, a key generator, and a decrypting section. The receiver receives a packet transmitted from an encrypting apparatus that executes an encrypting process. The key generator generates a key used for the encrypting process. The decrypting section decrypts cryptography data included in the packet received by the receiver with using the key generated by the key generator. In the decrypting apparatus, the packet received by the receiver includes packet information used for generating the key. The key generator generates the key with using the packet information.

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Fukuoka, Japan

Masakatsu Matsuo