摘要:
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.
摘要:
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.
摘要:
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≦N) among the N initial keys in each node, as the M node keys for the node.
摘要:
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.
摘要:
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≦N) among the N initial keys in each node, as the M node keys for the node.
摘要:
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.
摘要:
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.
摘要:
Such a device is disclosed that includes first and second chips stacked to each other, and a third chip controlling the first and second chips, stacked on the first and second chips, and including first, second and third output circuits. The first output circuit supplies a first command signal to the first chip. The second output circuit supplies the first command signal to the second chip. The third output circuit supplies a second command signal to the first and second chips.
摘要:
This invention can generate printed matter on which a multi-valued discrimination image of three values or more cannot be visually confirmed under ordinary light but can be visually confirmed via an infrared camera under infrared light. To this end, a holding unit holds items of color information C1, C2, and C3 each indicating usage amounts of printing materials of three types, used by a printing apparatus, which have a color difference under visible light not more than a pre-set threshold, and which have different infrared light ray absorption rates. When a latent image generating unit generates infrared light ray latent image data of three tones, a discrimination image data generating unit decides one color information item Ci (1≦i≦3) held by the holding unit, and outputs the decided Ci to an output unit which outputs the received pixel values to the printing apparatus.
摘要:
A semiconductor device includes: an interface chip including a read timing control circuit that outputs, in response to a command signal and a clock signal supplied from the outside, a plurality of read control signals that are each in synchronization with the clock signal and have different timings; and core chips including a plurality of internal circuits that are stacked on the interface chip and each perform an operation indicated by the command signal in synchronization with the read control signals. According to the present invention, it is unnecessary to control latency in the core chips and therefore to supply the clock signal to the core chips.