Signature and meta-transactions

Use personal_sign

This method create signature that can be useful off-chain, to verify that an user own a private key. For login purpose for instance. But this should not be used on-chain for smart contract.

Create a signature from a message

const signature = await ethersProvider.provider.request({
  method: "personal_sign",
  params: [message, account],
})

Recover public key of the signer

async function offChainRecover() {
  const hashedMessage = ethers.utils.id(
    "\x19Ethereum Signed Message:\n" + message.length + message
  )

  const address = ethers.utils.recoverAddress(hashedMessage, signature)
  setAddress(address)
}

Implement the EIP-712