ENCRYPTED COMMUNICATION METHOD AND ENCRYPTED COMMUNICATION SYSTEM USING THE SAME

摘要

PURPOSE: A cryptographic communication method and a cryptographic communication system using the same are provided to encode/decode an authentication key by using shared information of a server and a terminal. CONSTITUTION: A first terminal(100) transmits an encoded first authentication key to a server(110)(S410). The server generates a first authentication key by decoding the encoded first authentication key with a first public key(S420). A second terminal generates the first authentication key by decoding the encoded first authentication key(S440). The second terminal transmits an encoded second authentication key to the server by encoding the second authentication key(S450). The server generates the second authentication key by decoding the encoded second authentication key(S460). The server transmits the encoded second authentication key to the first terminal by encoding the second authentication key(S470). The first terminal generates the second authentication key by decoding and the second authentication key(S480).