Patent ID: 8566590

Claim:
An encryption information transmitting terminal for communicating with a destination device through a network connection comprising: a communication unit configured to transmit and receive a communication message; an authentication processor configured to perform an authentication process for establishing the network connection by transmitting and receiving an authentication message to and from an authentication server through the communication unit; a first message generator configured to generate a first communication message to the destination device, which includes an acquisition instruction of an SMK-EE (Smart Meter Key for End-to-End protection) from the authentication server; and a second message generator configured to generate a second communication message including data for the destination device, wherein the communication unit encrypts the first communication message with an SMK-HH (Smart Meter Key for hop by hop protection), transmits an encrypted first communication message to the destination device, encrypts the second communication message with the SMK-EE, and transmits an encrypted second communication message to the destination device, wherein the first communication message and the encrypted second communication message are transferred to the destination device through a relay, and wherein, when the authentication process is successfully completed, an EMSK (Extended Master Session Key) is generated according to a key generation algorithm given in advance and the SMK-EE and the SMK-HH are generated by using the EMSK as a master key.