DEVICE, SYSTEM, AND METHOD FOR PROVIDING DATA SECURITY, AND PROGRAM FOR ALLOWING COMPUTER TO EXECUTE THE METHOD

The steps executed by a server includes Step (520) of receiving plaintext ROM data encrypted with a business operator public key, Step (530) of decrypting the plaintext ROM data encrypted with the business operator public key, Step (535) of generating ciphertext ROM data, Step (540) of encrypting the ciphertext ROM data to generate the ciphertext ROM data encrypted with a client public key, Step (545) of transmitting the ciphertext ROM data to a client as an attached file of a mail, Step (550) of generating the ciphertext ROM data, and Step (565) of executing an application by combining a ROM with a microcontroller chip.