Canon Kabushiki Kaisha

Yuji Suga

Junichi Hayashi

Keiichi Iwamura

Yuji Kobayashi

Kentaro Matsumoto

Hidetomo Sohma

Hirowo Inoue

Masahiko Takaku

Jun Fujisawa

Katsuki Ishii

Nobuhiro Tagashira

To authenticate an authentication reference apparatus, authentication information generation reference data is transmitted to the authentication reference apparatus. First authentication reference data generated by the authentication reference apparatus using the authentication information generation reference data is acquired from the authentication reference apparatus. Second authentication reference data is generated using key information complying with a method of generating the first authentication reference data and the authentication information generation reference data. The first authentication reference data is compared with the second authentication reference data. The authentication reference apparatus is authenticated based on the comparison result.

Information processing apparatus, control method therefor, information processing system, and program

An object of this invention is to protect the right of a content holder without any necessity of a special storage medium incorporating a copyright protecting mechanism when the content holder does not coincide with a content creator. Information for encryption key generation is input. An encryption key is generated from the information for encryption key generation. Encryption key verification data is acquired from a storage medium, and the validity of the generated encryption key is authenticated based on the verification data. Generated data is encrypted by using the encryption key whose validity is authenticated by the authentication. The encrypted data is stored in the storage medium.

Method, apparatus, and computer program for generating session keys for encryption of image data

The present invention stores and manages only one piece of key information even if contents information includes a plurality of partial contents arranged in a sequence, and the partial contents are encrypted with different keys. When a piece of contents information includes four partial contents or divided into four partial contents, a key for each of four node positions is generated through four steps of operations from a key for the top root. Node keys P (i, 1) and P (i, i) at both sides are generated by a one-way function from node keys P (i&#x2212;1, 1) and P (i&#x2212;1, i&#x2212;1) at the upper i&#x2212;1layer, and a node key P (i, m) (m=2, 3, . . . , i&#x2212;1) are generated by a one-way function which can generate the keys from any of node keys P (i&#x2212;1, m&#x2212;1) and P (i&#x2212;1, m) at the upper i&#x2212;1layer, where jnode key at the ilayer is represented as P (i, j) (j=1, 2, . . . , i&#x2212;1). Then, each of partial contents is encrypted with key information generated at a terminal layer. If only a root key is saved, one encrypting key can be generated for a range of partial contents arranged in a sequence.

Information encryption apparatus and controlling method of the same, computer program and computer readable storage medium

An information processing method enables verification of validity of signed data using received partial signed data parts, even when all the signed data is not received. According to the information processing method, signature data including a signature value and digests of a plurality of partial signed data parts is received. Then, the signature data is verified by using the signature value and the digests of a plurality of partial signed data parts. Subsequently, the partial signed data is received according to a result of verifying the signature data. Then, the partial signed data is verified using the partial signed data and the digest of the partial signed data.

Information processing apparatus and method

A data generating device comprises a variable-length data input unit adapted to input variable-length data, an embedding unit adapted to embed identification data corresponding to format information indicating the format of the variable-length data to the variable-length data; an location information acquiring unit adapted to acquire location information showing locations corresponding to identification data in variable-length data; and an outputting unit adapted to output the variable-length data in which the identification data is embedded and the location information, wherein the variable-length data comprises a public key certificate.

Data generating device and control method thereof, data analyzing device and control method thereof, data processing system, program and machine-readable storage medium

Data of a directed graph is input (S), and is divided into subgraphs (S). Data of node key assignment tables are generated for respective divided subgraphs (step S). The respective node key assignment tables are merged (S).

Information processing method and information processing apparatus

It is possible to safely constitute a key management method having an access structure equivalent to the hierarchical key management method with a small amount of calculations. The method includes: a setting step for setting a set (,) of the number of times a one-way hash function is executed for each of the elements of the rank i; a key generation step for generating two separate keys for the elements as the value of the number of times the one-way function has been executed corresponding to the set of the number of times which has been set for the elements of the two original keys for each of the elements; and a key delivery step for delivering the two separate keys for the elements to each of the elements. Furthermore, the method includes an initial key generation step for calculating N keys with a route node positioned at the most significant node when generating a key at each node from a parent node and performing key delivery according to the hierarchical relationship expressed in a directed graph having no cycle; and a node key generation step for generating the value of the number of predetermined times the one-way function is executed according to the execution specification for M keys (M&#x2266;N) among the N initial keys in each node, as the M node keys for the node.

Key information processing method, device thereof, and program

To generate and verify signature data using a known signature algorithm whose safety is ensured from the viewpoint of calculation quantity and ensuring the authenticity thereof over a long time period. A message to be signed is transmitted, a padding-data item is added to the message, and a signature-data item of the message with the padding-data item added thereto is generated by using a hash function and a public-key cryptosystem. The addition step and the generation step are performed a predetermined number of times by using the signature-data item, as the padding-data item, and the signature-data items generated the predetermined number of times and the padding-data items added the predetermined number of times are externally transmitted with the message.

Signature-generation method, signature-verification method, public-key distribution method, and information-processing apparatus

Even when encoded (compressed) image data appended with an error-detecting code is encrypted, the apparatus which receives and reproduces that image data can execute a normal process without any insignificant re-send request and the like. To this end, encoded image data is input, and first error-detecting encoding information contained in its header is checked to determine whether or not an error-detecting code is appended. If it is determined that the error-detecting code is appended, the first error-detecting encoding information is changed to indicate the absence of an error-detecting code, and is saved as second error-detecting encoding information. Then, the encoded image data is encrypted.

Information processing method, apparatus, and information processing program

On an encrypted object code obtained by encrypting an object code, there is discriminated whether an inhibited code defined in data format is present in a code concerning such encrypted object code, and, in case such inhibited code is judged absent, the encrypted object code is determined as an encryption result of the object code.

Encryption/decryption method for data limited in value range, apparatus and program therefor

In an image process apparatus, a key different for each level of hierarchy is generated on the basis of a specific key with respect to image data having a hierarchical structure, the image data in each level of the hierarchy is encrypted using the generated key for each level, and the specific key is managed, so that key management can be easily performed while the image data having a hierarchical structure is enciphered using different keys for each level of the hierarchy.

Data process apparatus and method therefor

An object of this invention is to provide a data structure description method and processing method, which can present the contents of data to the user in every devices as much as possible. A data processing method of this invention has a parsing step of parsing a structured document having second data which is included in first data described in a first markup language, is described in a second markup language, and is required to present contents corresponding to the first data, and a processing step of executing, if it is determined in a determination step that a part described in the first markup language of the parsed structured document cannot be understood, a process of data on the basis of a part described in the second markup language.

Data structure, processing method of structured document described using that data structure, program for implementing the method, and storage medium storing the program

This invention provides structured document data and a contents processing method, which can assure high versatility and process each individual required information using an application corresponding to processing performance in each device, so as to solve the problems in the aforementioned conventional description method. Structured document data according to this invention has designation information that designates an item position of a list held in a first document element which holds item information associated with a reference destination of contents as a list, and a second document element that holds information required to present the contents at the reference destination described in the item information corresponding to the designation information.

Structured document data, contents processing method, program for implementing that process, and storage medium storing program

An exponent calculation apparatus calculates xbased on input two integers x and e. A pre-calculation module pre-calculates x^{l_i} for each of candidate exponents {l_i} (0&#x2266;i&#x2266;L&#x2212;1) stored in a candidate exponents storing unit, the number of the candidate exponents being L, and stores the obtained values x^{l_i} in a pre-calculated values storing unit. A dividing module divides the integer e into a plurality of values {f_i} (0&#x2266;i&#x2266;F&#x2212;1) so that each of the values {f_i} corresponds to one of the candidate exponents {l_i}. A sequential processing module sequentially updates a calculation result c, which is stored in a calculation result storing unit, for each of the values {f_i} by using each of the values x^{l_i}. The updated calculation result c for each of the values {f_i} is output as x. Accordingly, the amount of pre-calculation and table size can be reduced and thus the number of calculations can be reduced.

Exponent calculation apparatus and method, and program

A shared image generation apparatus generates a basis matrix on the basis of a graph, the vertex set of which corresponds to a set of a plurality of members to which shared images are to be distributed, and generates a plurality of shared images to be distributed to the plurality of members on the basis of the basis matrix and an externally input secret image to be shared. The plurality of generated shared images form the secret image when they are stacked up.

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Kawasaki, Japan

Yuji Suga