Abstract: A network communication method comprises connecting, by a server and client, through networks and sharing a symmetric key, generating, by the server, a credential by which the client can be identified, through random number generation, and sharing the credential with the client, generating, by the client, transmission data containing a serial number indicating the sequence of the transmission data, and transmitting a message to the server, and generating, by the server, transmission data containing a serial number indicating the sequence of the transmission data, and transmitting a message to the client. Accordingly, the present invention has an advantage in that when a connection between a server and client is interrupted, the connection can be automatically recovered using a credential, by which a connected terminal can be identified in a network environment between the server and the client, without a separate process for authenticating a reconnected terminal.