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US 2006/0149762 A1Published application
Key information processing method, device thereof, and program
AssigneeCanon Kabushiki Kaisha
InventorsYuji Suga, Junichi Hayashi
Life of this patent
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AssigneeCanon Kabushiki Kaisha
InventorsYuji Suga, Junichi Hayashi
Estimating the term…
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.
A key information processing method, comprising:
A key information processing apparatus, comprising:
A computer-readable program used to direct a computer to execute a key information processing method, comprising:
A key information processing method for delivering a key by generating a key at each node from a parent node according to a hierarchical relationship expressed in a directed graph having no cycle, comprising:
A key information processing apparatus for generating a key at each node from a parent node according to the hierarchical relationship expressed in a directed graph having no cycle includes:
A computer-readable program in a key information processing method for generating a key at each node from a parent node according to a hierarchical relationship expressed in a directed graph having no cycle, the program causing a computer to execute the key information processing method, the method comprising:
Dependencies are inferred from the claim text.