Secure payment and authentication system having security function enhanced by using quantum cryptography

A relay device for quantum cryptography communication, the relay device comprising:

• an optical receiver unit configured to receive a series of first quantum signals generated by a first quantum filter and sent from a communication device;
• an optical transmission unit configured to transfer the series of first quantum signals to a server;
• and
• a processor configured to:
• identify information about the first quantum filter received from the communication device;
• control the optical receiver unit to receive the series of first quantum signals by passing the series of first quantum signals through the first quantum filter based on the identified information about the first quantum filter;
• and
• control the optical transmission unit to transfer the series of received first quantum signals to the server.

A relay method for quantum cryptography authentication, the relay method comprising:

• receiving a series of second quantum signals generated in such a manner that a series of first quantum signals generated by a first quantum filter and sent from a communication device pass through a second quantum filter;
• transferring the series of second quantum signals to a server;
• controlling quantum signal generation characteristics based on information about the second quantum filter;
• and
• performing user authentication in conjunction with the communication device by using a secret key generated from the series of second quantum signals based on the information about the second quantum filter and information about the first quantum filter provided by the communication device.

A relay method for quantum cryptography communication, the relay method comprising:

• identifying information about a first quantum filter received from a communication device;
• controlling characteristics of a quantum signal generation circuit by means of the first quantum filter based on the identified information about the first quantum filter;
• receiving a series of first quantum signals, generated and sent by the first quantum filter by means of which the characteristics of the quantum signal generation circuit have been controlled, from the communication device;
• and
• transferring the series of first quantum signals to a server via the first quantum filter.