Domain name system (DNS) and domain name service method based on user information

A domain name service system based on user information, the domain name service system comprising:

• a client apparatus including an agent that outputs a domain name query comprising a domain name system (DNS) request message having user information added thereto;
• a first DNS server that receives the domain name query from the client apparatus, and outputs the domain name query;
• a second DNS server whose name server information is not published, that replaces the first DNS server when the first DNS server cannot operate due to an external attack or operation failure;
• and
• a database system that:
• receives the domain name query from the first DNS server;
• extracts the user information included in the received domain name query;
• and
• provides the first DNS server with destination path information for the extracted user information and path information of the second DNS server, wherein the path information of the second DNS server is not published, and is assigned differently for each received user information;
• wherein the first DNS server further:
• receives the destination path information corresponding to the domain name query of the client apparatus and the path information of the second DNS server from the database system;
• and
• transmits the destination path information and the path information of the second DNS server to the client apparatus, and
• wherein the agent of the client apparatus further:
• receives the destination path information and the path information of the second DNS server from the first DNS server in response to the domain name query and sends the destination path information and the path information of the second DNS server to the client apparatus;
• stores the path information of the second DNS server;
• outputs a subsequent domain name query comprising a domain name system (DNS) request message having user information added thereto to the first DNS server;
• and
• outputs a domain name query to the second DNS server by using the stored path information of the second DNS server-when the first DNS server cannot operate due to an external attack or operation failure for the subsequent domain name query.