Apparatus and method for transmitting sensitive data using relay

A method of transmitting sensitive data, comprising:

• receiving, by a data transmission apparatus, a pilot signal from a relay and a data reception apparatus;
• receiving a pilot signal transferred by the data reception apparatus and relayed by the relay;
• estimating a state of a wireless channel between the data transmission apparatus and the relay or the data reception apparatus using the pilot signal;
• extracting an encryption key stream from information including the state of the wireless channel;
• performing an error correction encoding process on plain text data to be transmitted, and encrypting the pain text data using the encryption key stream;
• transferring the pilot signal to the data reception apparatus;
• and
• relaying and transmitting the encrypted plain text data to the data reception apparatus using the relay.

An apparatus for transmitting sensitive data, comprising:

• a receiver configured to receive a pilot signal via an antenna, and to estimate a state of a wireless channel using the received pilot signal;
• a key generation unit configured to generate an encryption key stream based on information including the state of the wireless channel;
• and
• a transmitter configured to transmit plain text data using the encryption key stream, or to transmit a pilot signal.