System and method of transmitting/receiving security data

A system including a user terminal, a service providing server and a security server for intermediating transmission/reception of the security data between the user terminal and the service providing server, comprising:

• the security server configured to generate a session key corresponding to a secret key provided from the user terminal, receive security data together with the session key from a security data transmitter, which is one of the user terminal and the service providing server, encode the security data with the secret key corresponding to the session key, store the encoded security data, generate a data key of the security data, generate a data encryption key by encoding the data key with the secret key, provide the data encryption key to a security data transmitter, decode the encoded security data with the secret key corresponding to the session key when the session key is received together with the security data request key from the security data receiver, which is the other one of the user terminal and the service providing server, and provide the decoded security data to the security data receiver;
• the user terminal configured to generate the secret key, transmit the session key and the security data and provide the data encryption key to the service providing server in case of the security data transmitter, and receive the data encryption key from the service providing server, transmit the session key and the security data request key to the security server and receive the decoded security data from the security server in case of the security data receiver;
• and
• the service providing server configured to transmit the session key and the security data to the security server and provide the data encryption key transmitted from the security server in case of the security data transmitter, receive the session key and the data encryption key from the user terminal, transmit the session key and the security data request key to the security server and receive the decoded security data from the security server in case of the security data receiver.

A method of intermediating transmission/reception of security data between a service providing server and a user terminal, comprising:

• generating a session key corresponding to a secret key provided from the user terminal;
• providing the session key to the user terminal;
• receiving security data together with the session key from a security data transmitter, which is one of the user terminal and the service providing server;
• encoding the security data with the security key corresponding to the session key;
• generating a data key of the encoded security data;
• encoding the data key with the secret key to generate a data encryption key;
• providing the data encryption key to the security data transmitter;
• associating and storing the secret key, the session key, the data key and the encoded security data;
• decoding the encoded security data with the secret key corresponding to the session key when the session key and a security data request key are received from a security data receiver, which is one of the service providing server and the user terminal;
• and
• providing the security data to the security data receiver.

A storage medium storing computer readable instructions for performing a method of intermediating transmission/reception of security data between a service providing server and a user terminal, wherein the method comprises:

• generating a session key corresponding to a secret key provided form the user terminal;
• providing the session key to the user terminal;
• receiving security data together with the session key from a security data transmitter, which is one of the user terminal and the service providing server;
• encoding the security data with the security key corresponding to the session key;
• generating a data key of the encoded security data;
• encoding the data key with the secret key to generate a data encryption key;
• providing the data encryption key to the security data transmitter;
• associating and storing the secret key, the session key, the data key and the encoded security data;
• decoding the encoded security data with the secret key corresponding to the session key when the session key and a security data request key are received from a security data receiver, which is one of the service providing server and the user terminal;
• and
• providing the security data to the security data receiver.