Device and method for security key exchange and system pertaining to same

A method for enabling a client device to share a security key for data communication with a counterpart communication device, the method comprising steps of:

• dividing a public key generated by the client device into two public key halves;
• transmitting one of the two divided public key halves in a signaling route to the counterpart communication device;
• transmitting the other public key half and public information signed by a personal key generated automatically in a media route to the counterpart communication device;
• predicting a public key generated automatically in the counterpart communication device by using the two public key halves received from the counterpart communication device through the signaling route and the media route;
• performing a verification of the predicted public key and signed counterpart public information having been received from the counterpart communication device in the media route;
• and
• upon a successful verification of the predicted public key and the signed counterpart public information, generating a master key for use in a data communication with the counterpart communication device.