Exploring the Use of NFT for Identification Verification

NFT (Non-Fungible Token) as a unique digital asset is very suitable for use as an identification verification tool. This article will explore how to use NFT as a registration certificate through a simple example.

Preparation Work

We will use the following tools:

1. SPL Token: A general Token program implementation provided by Solana, which is part of the Solana Program Library (SPL).

2. Solana Playground: An online environment for writing and deploying Solana contracts, with built-in tools such as SPL Token.

Create Verification Token

We will create an NFT Token as a verification credential. Users mint (Mint) this Token, which is regarded as registration in the system.

Create Token

Create a new indivisible Token using spl-token:

spl-token create-token --decimals 0

This will create a Mint Address as the unique identification of the Token.

Create Token Account

Create a Token Account for the newly created Token:

spl-token create-account <mint_address>

Mint Token

Try to mint a Token unit for the Token Account:

spl-token mint <mint_address> 1

Since we set decimals to 0, we can only mint whole Token.

mints for user wallet

Minting Tokens for user wallets requires two steps:

1. Create Token Account for User Wallet
2. Use the Token Account to mint Tokens

This is because we do not have the authority to directly modify user wallet data.

Query user Token holding status

You can check whether a user holds our NFT through the getTokenAccountsByOwner method of the RPC interface.

Implementing a Login System

Based on the above principles, we can implement a simple NFT login system:

1. Create a Nextjs project
2. Use Ant Design Web3 to implement wallet connection
3. Implement the sign-in and sign-on pages
4. sign-in: Check if the user has registered ( and whether they hold NFT).
5. sign-on: Create a Token Account for new users and mint NFT

Users need to sign-on for registration the first time they use it, and then they can directly sign-in to log in.

Throughout the process, we utilized whether users hold specific NFTs as registration verification, implementing a blockchain-based decentralized identification verification system. This method eliminates the need for a centralized database to store user information, enhancing security and privacy protection.

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