摘要:
A radio frequency system and a password management method applied to a storage device of the radio frequency system are provided, in which a first access password is stored for deciding whether to permit access to information and a first changed password. The first changed password, a second access password, and a second changed password are received, and the first access password is changed to the second access password, and the first changed password is changed to the second changed password. Accordingly, information access authority in the storage device and a password change authority can be exclusively transferred according to the transfer of management of the storage device, and information leakage caused by a previous manager's password leakage or a third person's password leakage can be prevented.
摘要:
Provided are a method of managing data in a network system and a network system using the method. The method includes substituting a master password for a predetermined function to generate a password; if a password for requesting an access to specific data is input, checking whether the input password matches with the generated password; and if the input password matches with the generated password, allowing the access to the specific data. Thus, in a case where a storage unit makes access levels of data into multilayered access levels to authenticate a password, the storage unit can store only a password to efficiently authenticate and manage an access to data.
摘要:
A combination-based broadcast encryption method includes: assigning by a server a base group of different combinations to each user; producing and sending secret information for each user by using as a base the base group allocated to each user; producing and sending an inverse-base parameter value through calculations with integers used to produce the base group and key value information of one or more privileged users; and deriving a group key by using the key value information of the privileged users, encrypting a session key by using the derived group key, and sending the encrypted session key to each user. Accordingly, each user is assigned a different base through a combination, thereby having security against collusion attacks.
摘要:
A user key management method for a broadcast encryption includes assigning node path identifiers (IDs) to nodes arranged in sequence; assigning random seed value keys to the nodes according to the node path IDs; generating key values by repeatedly applying a hash function to the assigned random seed value keys; and assigning the generated key values to the nodes in sequence. Accordingly, it is possible to reduce the transmission overhead that is most important matter in the broadcast encryption to less than the number of the revoked users. Further, there is an advantage that the transmission overhead of the exemplary embodiments of the present invention is remarkably reduced compared with the Subset Difference method.
摘要:
A hierarchical threshold tree-based broadcast encryption method includes a first step for a server initialization and a user subscription, a second step of distributing a message to enable a privileged user (authorized user) to decrypt a group key, and a third step of the privileged user (authorized user) decrypting the message using the group key. According to the method, it is possible to prevent any group of revocators from obtaining the group key using their secret information and information being broadcast by the server.
摘要:
An apparatus and method for generating a key for a broadcast encryption. The apparatus includes a node secret generator for managing a user that receives broadcast data in a tree structure and for generating a unique node secret for each node in the tree structure. The apparatus also includes an instant key generator for temporarily generating an instant key used at all nodes in common in the tree structure, and a node key generator for generating a node key for each node by operating the node secret generated at the node secret generator and the instant key generated at the instant key generator. Thus, key update can be efficiently achieved.
摘要:
A hierarchical threshold tree-based broadcast encryption method includes a first step for a server initialization and a user subscription, a second step of distributing a message to enable a privileged user (authorized user) to decrypt a group key, and a third step of the privileged user (authorized user) decrypting the message using the group key. According to the method, it is possible to prevent any group of revocators from obtaining the group key using their secret information and information being broadcast by the server.
摘要:
A combination-based broadcast encryption method includes: assigning by a server a base group of different combinations to each user; producing and sending secret information for each user by using as a base the base group allocated to each user; producing and sending an inverse-base parameter value through calculations with integers used to produce the base group and key value information of one or more privileged users; and deriving a group key by using the key value information of the privileged users, encrypting a session key by using the derived group key, and sending the encrypted session key to each user. Accordingly, each user is assigned a different base through a combination, thereby having security against collusion attacks.
摘要:
An apparatus and method for generating a key for a broadcast encryption. The apparatus includes a node secret generator for managing a user that receives broadcast data in a tree structure and for generating a unique node secret for each node in the tree structure. The apparatus also includes an instant key generator for temporarily generating an instant key used at all nodes in common in the tree structure, and a node key generator for generating a node key for each node by operating the node secret generated at the node secret generator and the instant key generated at the instant key generator. Thus, key update can be efficiently achieved.
摘要:
A hybrid broadcast encryption method is provided. The hybrid broadcast encryption method includes setting initialization values, generating a node secret using the initialization values; generating a private secret using the node secret; sending the node secret and the private secret; generating a broadcast message based on a revoked group; encrypting a session key using a key encryption key (KEK) which is allocated to every user group and the broadcast message; and broadcasting to every user the encrypted session key and the broadcast message.