Method and device for proving originality of creative design in communication system

An operating method of a first terminal including a transceiver, a memory, a processor, an input device, an output device, and a camera in a communication system, the operating method comprising:

• capturing, by the camera, a plurality of intermediate images in creation stages of a design and one final image, wherein the plurality of intermediate images are captured during creation times of the creation stages of the design and the final image is captured during a final creation time of the design;
• extracting, by the processor, a plurality of pieces of binary metadata from the plurality of intermediate images and the final image;
• inputting, by the processor, the plurality of pieces of binary metadata to a first function stored in the memory to generate a plurality of pieces of intermediate image hash information and final image hash information;
• generating, by the processor, final hash information based on the plurality of pieces of intermediate image hash information and the final image hash information using a second function stored in the memory, wherein the second function is configured to generate the final hash information differently depending on an order of computation of the plurality of pieces of intermediate image hash information and the final image hash information;
• generating, by the processor, first block information about a first non-fungible token (NFT) based on information related to the first terminal, information on the final image, and the final hash information;
• transmitting, by the transceiver, the first block information to a blockchain network;
• receiving, by the transceiver, a proof request message for the plurality of intermediate images generated in a creation process of the final image corresponding to the first NFT from a second terminal which is one of a plurality of nodes constituting the blockchain network;
• and
• transmitting, by the transceiver, a proof response message including information on the plurality of intermediate images, information on the first function, information on the second function, and information on the order of computation to the second terminal.