Security device and security program

A security program stored in a medium for performing the steps of:

• generating a random number based on a radio frequency (RF) signal from an external electronic device;
• encrypting data using the generated random number;
• and
• transmitting the encrypted data to an external electronic device.

A security device comprising:

• a communication antenna for receiving a communication signal;
• an encryption unit for encrypting data with an encryption key;
• and
• a control unit for transmitting encrypted data to an external electronic device through the communication antenna,
• wherein the encryption key of the encryption unit and the encryption key used by the external electronic device to decrypt the encrypted data are derived from different source keys, and
• the source key of the encryption key of the encryption unit is not transmitted to the external electronic device.

A security program stored in a medium for performing the steps of:

• generating a random number based on a radio frequency (RF) signal from an external electronic device;
• generating a private encryption key (Priv_Sender) from the random number;
• generating a public encryption key (Pub_Sender) from the private encryption key (Priv_Sender);
• generating a first shared encryption key from the private encryption key (Priv_Sender) and the public encryption key (Pub_Receiver) of the external electronic device that receives encrypted data;
• and
• encrypting data with the shared encryption key and transmitting the data together with the public encryption key (Pub_Sender).