Patent ID: 7984290
Filing Date: 2011-07-19
Classification: H04L

Abstract:
1. An encrypting communication method for a communication system including an internal communication terminal coupled to an intra-organization network, an external communication terminal for accessing the internal communication terminal from outside of the intra-organization network, and a management server for managing the internal communication terminal and the external communication terminal, wherein: the internal communication terminal, in response to success of validation for a certificate of the management server, performs a first authentication for the management server, and establishes a first encryption communication path between the internal communication terminal and the management server after the first authentication is successfully performed, the internal communication terminal being configured not to establish a communication path operable under encryption with the management server in response to failure of the first authentication; the external communication terminal performs a second authentication for the management server, establishes a second encryption communication path between the external communication terminal and the management server after the second authentication is successfully performed, and transmits a connection request for the internal communication terminal to the management server through the second encryption communication path between the external communication terminal and the management server, the external communication terminal being configured not to establish a communication path operable under encryption with the management server in response to failure of the second authentication; the management server generates an encryption communication key for encrypting communication between the external communication terminal and the internal communication terminal and setting information for the encrypting communication, and transmits together the connection request for connection received from the external communication terminal, the generated encryption communication key, and the setting information to the internal communication terminal by using the established first encryption communication path between the internal communication terminal and the management server; the internal communication terminal supplies a judgment result as to whether the connection request from the external communication terminal is permitted, to the management server through the first encryption communication path between the internal communication terminal and the management server; if the judgment result received from the internal communication terminal indicates that the connection request is permitted, the management server transmits the generated encryption communication key to the external communication terminal via the established second encryption communication path between the external communication terminal and management server; the external communication terminal and the internal communication terminal establish a third encryption communication path between the external communication terminal and the internal communication terminal, by using the encryption communication key respectively received at the external communication terminal and at the internal communication terminal from the management server; and the external communication terminal performs encryption communication with the internal communication terminal without involving the management server through the established third encryption communication path between the external and internal communication terminals.