NFT protocol consists of two roles: NFT owner and NFT buyer.

- NFT Digitize. An NFT owner checks that the file, title, description are completely accurate. Then, s/he digitizes the raw data into a proper format.

- NFT Store. An NFT owner stores the raw data into an external database outside the blockchain. Note that, s/he is also allowed to store the raw data inside a blockchain, despite this operation is gas-consuming.

- NFT Sign. The NFT owner signs a transaction, including the hash of NFT data, and then sends the transaction to a smart contract.

- NFT Mint&Trade. After the smart contract receives the transaction with the NFT data, the minting and trading process begins. The main mechanism behind NFTs is the logic of the Token Standards.

- NFT Confirm. Once the transaction is confirmed, the minting process completes. By this approach, NFTs will forever link to a unique blockchain address as their persistence evidence.

For the next example the protocol consists of two roles: NFT creator and NFT buyer. In most cases, a buyer can also act as a creator because an NFT product is created based on random seeds when a buyer bids for it. This extends the functions in terms of user customization.

- Template Create∗. The project founder initiates a template via the smart contract to set up several basic rules, such as different features (character style, weapons, or accessories) in the game.

- NFT Randomize∗. Once a buyer bids for an NFT, s/he can customize the NFT product with a set of additional features on top of basic lines. These additional features are randomly selected from a database that was predefined at the initial state.

- NFT Mint&Trade. The minting and trading process starts once the cor- responding smart contract is triggered.

- NFT Confirm. All the procedures are conducted through smart contracts. The generated NFT will be persistently stored on-chain when the consensus procedure has been completed.