Patent ID: 7774592

Claim:
An encrypted communication method characterized by comprising the steps of: a) causing a communication method resolution unit to determine on the basis of a domain name contained in one of a name resolution query transmitted from an application that communicates with a node apparatus connected to a network to resolve an IP address of the node apparatus and a name resolution response as a response to the name resolution query whether the node apparatus is an encrypted communication target node; b) causing an encrypted communication path setting unit to register the IP address of the node apparatus in an encrypted communication path setting table when the node apparatus is the encrypted communication target node; c) causing a name resolution query/response transmission/reception unit to transmit the IP address of the node apparatus contained in the name resolution response to the application; d) causing the application to transmit a data packet in which the IP address of the node apparatus is set as a destination address; and e) causing a data transmission/reception unit to receive the data packet transmitted from the application and, if a communication partner IP address set as the destination address of the data packet is registered in the encrypted communication path setting table, encrypt and transmit the data packet.