Abstract: A policy that relates attributes of an agent to a role is distributed to each agent on a network. A field connector generates an internal field in accordance with an instruction of a security manager. A ROLE manager uses attribute information from an attribute manager, and assigns each agent a ROLE in accordance with the attributes of each agent, and installs a ROLE method table and a ROLE execution part. When receiving a message from an external network, each agent searches for a corresponding ROLE by referring to the ROLE method table, and executes the ROLE. Thus, collaboration among agents is realized through a virtual communication channel based on the exchange of a message.

Abstract: A policy that relates attributes of an agent to a role is distributed to each agent on a network. A field connector generates an internal field in accordance with an instruction of a security manager. A ROLE manager uses attribute information from an attribute manager, and assigns each agent a ROLE in accordance with the attributes of each agent, and installs a ROLE method table and a ROLE execution part. When receiving a message from an external network, each agent searches for a corresponding ROLE by referring to the ROLE method table, and executes the ROLE. Thus, collaboration among agents is realized through a virtual communication channel by means of the exchange of a message.

Abstract: A content distribution system involves a terminal unit of a user, a server of a third party and a terminal unit of a content distributor such as a copyright holder. The user's terminal unit is provided with a tamper-resistant device which can store data confidentially. The server of the third party supplies the user's terminal unit with data relating to a decrypting key needed to decode the encrypted content sent from the content distributor's terminal unit. Based on the supplied data from the third party, the decrypting key is produced confidentially within the tamper-resistant device.

Abstract: A policy that relates attributes of an agent to a role is distributed to each agent on a network. A field connector generates an internal field in accordance with an instruction of a security manager. A ROLE manager uses attribute information from an attribute manager, and assigns each agent a ROLE in accordance with the attributes of each agent, and installs a ROLE method table and a ROLE execution part. When receiving a message from an external network, each agent searches for a corresponding ROLE by referring to the ROLE method table, and executes the ROLE. Thus, collaboration among agents is realized through a virtual communication channel by means of the exchange of a message.

Abstract: A content distribution system includes a data processing apparatus of a user for receiving a content supplied from a content transmitter, a data processing apparatus of a third party trusted by both the content transmitter and the user, and a communications network connecting the data processing apparatuses of the user and the third party for mutual data communication. The data processing apparatus of the user is provided with a tamper-resistant device storing data inaccessible from outside. The data processing apparatus of the third party transmits first data to the data processing apparatus of the user, wherein the first data relates to an encryption key that decodes a cipher generated by the content transmitter. The encryption key is obtained only within the tamper-resistant device. The tamper-resistant device decodes the cipher by using the first data from the data processing apparatus of the third party.

Abstract: A policy that relates attributes of an agent to a role is distributed to each agent on a network. A field connector generates an internal field in accordance with an instruction of a security manager. A ROLE manager uses attribute information from an attribute manager, and assigns each agent a ROLE in accordance with the attributes of each agent, and installs a ROLE method table and a ROLE execution part. When receiving a message from an external network, each agent searches for a corresponding ROLE by referring to the ROLE method table, and executes the ROLE. Thus, collaboration among agents is realized through a virtual communication channel by means of the exchange of a message.