SIWE: A Powerful Tool to Enhance Dapp Identification Capability

SIWE (Sign-In with Ethereum) is a method for verifying user identification on Ethereum, similar to initiating a transaction to prove user control over a wallet. Currently, the identification process has been greatly simplified, requiring only a signature on the information within the wallet plugin, and most common wallet plugins support this functionality.

This article mainly discusses the signing scenarios on Ethereum and does not involve other blockchains such as Solana, SUI, etc.

When is SIWE Required

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

• Have an independent user system
• Need to query information related to user privacy

For applications whose main function is querying, such as blockchain explorers, SIWE does not need to be used.

Although it seems that identification has been proven after connecting the wallet on the Dapp, this is only effective on the front end. For interface calls that require back-end support, simply passing the address is not enough, as the address is public information and can be easily spoofed.

How SIWE Works

The SIWE process can be summarized in three steps: connect wallet, sign, obtain identification.

1. Connect Wallet: Connect the user wallet in the Dapp through the wallet plugin.

2. Signature:

   • Get Nonce value: Call the backend API to obtain a randomly generated Nonce value.
   • Wallet Signature: Construct the signature content that includes Nonce value, domain name, chain ID, and other information, and sign it using the method provided by the wallet.
   • Send Signature: Send the signature to the backend for verification.

3. Obtain identification: After the backend verifies the signature, it returns the user identification (e.g., JWT). In subsequent requests, including the address and identification can prove wallet ownership.

Practical Guide

This article uses Next.js to develop a full-stack application, integrating SIWE functionality. The following are the main steps:

1. Install dependencies: Use create-next-app to create a project and install SIWE-related dependencies.

2. Introduce Wagmi: Import WagmiProvider in layout.tsx and configure SIWE related interfaces.

3. Add connection button: Implement a button component for connecting wallets and signing.

4. Interface Implementation:
   • Nonce generation: Create a random string and associate it with the address.
   • Signature verification: The backend verifies the signature content, checks the Nonce value, and generates the JWT.

5. Optimization: It is recommended to use dedicated node services (such as ZAN) to improve interface response speed.

By following the above steps, a basic SIWE login framework can be implemented, providing a more secure and reliable identification mechanism for Dapps.