SIWE User Guide: Empower Your Dapp

SIWE(Sign-In with Ethereum) is a method of verifying user identity on Ethereum, similar to initiating a transaction from a wallet, proving the user's control over the wallet. Currently, identity verification has become very simple; it only requires signing information in the wallet plugin, and most common wallet plugins already support it. This article mainly discusses the signing scenarios on Ethereum.

Do you need SIWE

If your Dapp has the following requirements, you may consider using SIWE:

• Has its own user system
• Need to query information related to user privacy

But if your Dapp is mainly for querying functions, such as applications similar to etherscan, then SIWE may not be necessary.

You might wonder, once you connect your wallet on the Dapp, doesn't that already prove wallet ownership? This only holds true for the front end. For interface calls that require back-end support, merely passing the address is not enough, as the address is public information and anyone can "borrow" your identity.

Principle and Process of SIWE

The SIWE process can be summarized in three steps: connect wallet - sign - obtain identity token.

Connect Wallet

This is a common Web3 operation, connecting a wallet in a Dapp through a wallet plugin.

signature

The signing steps include obtaining the Nonce value, wallet signing, and backend signature verification.

The backend generates a random Nonce value and associates it with the address. After the frontend obtains the Nonce value, it constructs the signature content, including the Nonce value, domain name, chain ID, etc., and signs it using the method provided by the wallet. Finally, the signature is sent to the backend.

Obtain identity identification

After the backend verification of the signature is successful, return the user identity identifier (, such as JWT ). The frontend should include the address and identity identifier in subsequent requests to prove wallet ownership.

Practice SIWE

We will develop a simple SIWE demo using Next.js to showcase the basic process. Note that this demo is for introductory purposes only, and using it in a production environment may pose security risks.

preparation work

1. Install Next.js

npx create-next-app@14

2. Install SIWE related dependencies

npm install antd @ant-design/web3 @ant-design/web3-wagmi wagmi viem @tanstack/react-query --save

3. Import WagmiProvider in layout.tsx

4. Implement the connect wallet button

5. Implement backend interfaces

   • Nonce generation
   • Signature Verification

6. Optimization: Use dedicated node services to improve response speed

By following the above steps, we have implemented a basic SIWE login framework. Using professional node services can significantly improve validation speed, and it is recommended to adopt this in a production environment.