Control system and multicast communication method

A control system comprising:

• a plurality of field equipments that are connected mutually to an IP network;
• a key management server that is connected mutually to the IP network and issues key information for authentication of the plurality of field equipments and security communication;
• an attribute server that is connected mutually to the IP network, and manages or provides attribute information for mutual authentication between the field equipments, and contains preset group information for multicast communication in a particular multicast group;
• and
• a GCKS server connected mutually to the IP network, wherein each of the field equipments is operable to:
• a) perform authentication of the key management server;
• b) acquire information of the attribute server existing on the IP network;
• c) register information of each of the field equipments itself in the attribute server;
• d) acquire startup information from the attribute server;
• e) receive a notification of the group information from the attribute server;
• f) participate in a particular multicast group using the GCKS server;
• g) receive a distribution of secret information from the GCKS server;
• and
• h) perform multicast communication based on the group information and the secret information.

A multicast communication method causing a field equipment to perform operations comprising:

• a) performing authentication of a key management server;
• b) acquiring information of an attribute server existing on an IP network;
• c) registering information of the field equipment itself in the attribute server;
• d) acquiring startup information from the attribute server;
• e) receiving a notification of group information which is necessary for the multicast communication in a particular multicast group from the attribute server;
• f) participating in the particular multicast group using a GCKS server function;
• g) receiving a distribution of secret information from the GCKS server function, and
• h) performing multicast communication based on the group information and the secret information.

A multicast communication method causing a field equipment to perform operations comprising:

• a) performing authentication of a key management server;
• b) acquiring information of an attribute server existing on an IP network;
• c) registering information of the field equipment itself in an attribute server;
• d) acquiring startup information from the attribute server;
• e) receiving a notification of group information from the attribute server;
• f) participating in a particular multicast group using a GCKS server;
• g) receiving a distribution of secret information from the GCKS server;
• and
• h) performing multicast communication based on the group information and the secret information.

A field equipment storing a program for executing a method comprising:

• a) performing authentication of a key management server;
• b) acquiring information of an attribute server existing on an IP network;
• c) registering information of the field equipment itself in the attribute server;
• d) acquiring startup information from the attribute server;
• e) receiving a notification of group information which is necessary for the multicast communication in a particular multicast group from the attribute server;
• f) participating in the particular multicast group using a GCKS server function;
• g) receiving a distribution of secret information from the GCKS server function, and
• h) performing multicast communication based on the group information and the secret information.