Patent ID: 7975291

Claim:
A network system in which a network node machine performs intercommunication, the network node machine comprising: a plurality of agents operable in parallel and hardware resources and software resources being managed by an agent corresponding to each resource, and the network system being built as a logical hierarchical structure by realizing communication units of the agents, wherein the network system being built as the logical hierarchical structure is a hierarchical agent community having a directed acyclic graph structure, and wherein each of the agents comprises: a first storage unit storing, as a lower community, a group of agents comprising a group of agents to which access is not limited and a group of agents to which access is limited, a second storage unit storing an access permission/rejection determination policy for an agent to which access is limited; and a security management unit determining, when an access request is issued by another agent, whether a message is to be transferred to an agent to which access is limited by referring to the first storage unit, and performing, when an access request is issued to an agent to which access is limited, access permission/rejection control to an agent to be accessed, referring to the second storage unit, and checking whether or not an access condition is satisfied depending on whether or not a condition indicated by a logic equation of a predicate logic in Symbolic Logic is satisfied wherein, an access request issued by another agent comprises attribute information including attribute of the another node and given in a predicate logic, and the security management unit checks whether or not the attribute information satisfies an access condition to the agent to be accessed by investigating whether or not a condition indicated by a logic equation of a predicate logic is satisfied, wherein the security management unit performs, when receiving a subscription request information to the community transmitted from another agent including policy information, permission/rejection of the community, and adds an agent of which subscription to the community is permitted as an agent within the community in the first storage unit.