Method, apparatus and system for secure data communication

A method of receiving, by a second device, encrypted data, the method comprising:

• receiving a data set comprising encrypted data and key identification information from a first device;
• obtaining an encryption key with respect to the first device by using the key identification information;
• decrypting the encrypted data by using the obtained encryption key,
• wherein the key identification information comprises information of the first device, which is identifiable by the second device, and information for identifying the encryption key,
• wherein the method further comprises receiving at least one nonce from at least one device comprising the first device, and transmitting a second nonce to each of the at least one device, and
• wherein the key identification information comprises information for identifying the first device based on the at least one nonce or the second nonce.

A first device transmitting encrypted data, the first device comprising:

• a controller configured to generate an encryption key, generate key identification information by using the generated encryption key, and encrypt data;
• and
• a transceiver configured to transmit a data set comprising the encrypted data and the key identification information to a second device,
• wherein the key identification information comprises information of the first device, which is identifiable by the second device, and information for identifying the encryption key,
• wherein the transceiver is further configured to transmit a first nonce to the second device, and receive a second nonce from the second device, and
• wherein the key identification information comprises information for identifying the first device based on the first nonce or the second nonce.

A method of sharing, by a first device, a key for encrypted data transmission, the method comprising:

• determining, based on a communication history, whether a first public key of a first device transmitted to a second device, and a first private key of the first device corresponding to the first public key of the first device, are stored;
• generating a second public key of the first device and a second private key of the first device based on a result of the determining;
• signing the generated second public key of the first device with the first private key of the first device;
• transmitting the signed second public key to the second device;
• receiving, from the second device, a second public key of the second device, which is signed with a first private key of the second device;
• obtaining a first public key of the second device, which corresponds to the first private key of the second device, based on the communication history;
• verifying the signed second public key by using the obtained first public key of the second device;
• and
• performing encryption communication based on a result of the verifying.