Multi-Sig accounts

Multi-signature (multi-sig) accounts provide an enhanced security mechanism by requiring multiple approvals (signatures) for transactions. This guide will walk you through setting up a multi-sig account, signing and broadcasting transactions using seid.

Creating a multi-sig account

1. Adding Accounts to Your Local Keychain

First, add two accounts to your local keychain:

seid keys add ms1
seid keys add ms2

These commands create two key pairs named ms1 and ms2.

2. Creating a Multi-Sig Account

Next, create a multi-sig account that requires signatures from both ms1 and ms2:

seid keys add ms1ms2 --multisig-threshold=2 --multisig=ms1,ms2

This command sets up a multi-sig account named ms1ms2 with a threshold of 2, meaning it requires signatures from both ms1 and ms2 to authorize transactions.

Signing and Broadcasting a Transaction

Here are the steps to sign and broadcast a transaction from a multi-sig account.

1. Define an Unsigned Transaction

Create an unsigned-tx.json file with your unsigned transaction. Below is an example of a JSON structure for sending tokens using a bank send message:

{
  "body": {
    "messages": [
      {
        "@type": "/cosmos.bank.v1beta1.MsgSend",
        "from_address": "MULTI_SIG_ACCOUNT",
        "to_address": "DESIRED_DESTINATION_ADDRESS",
        "amount": [
          {
            "denom": "usei",
            "amount": "10"
          }
        ]
      }
    ],
    "memo": "",
    "timeout_height": "0",
    "extension_options": [],
    "non_critical_extension_options": []
  },
  "auth_info": {
    "signer_infos": [],
    "fee": {
      "amount": [
        {
          "denom": "usei",
          "amount": "100000"
        }
      ],
      "gas_limit": "200000",
      "payer": "",
      "granter": ""
    }
  },
  "signatures": []
}

Replace MULTI_SIG_ACCOUNT with your multi-sig account address and DESIRED_DESTINATION_ADDRESS with the recipient’s address.

2. Sign the Unsigned Transaction

Sign the unsigned transaction from both ms1 and ms2:

seid tx sign unsigned-tx.json --multisig=multisigAccountName --from=ms1 --output-document=signer1_signedTx.json --node YOUR_RPC_URL
 
seid tx sign unsigned-tx.json --multisig=multisigAccountName --from=ms2 --output-document=signer2_signedTx.json --node YOUR_RPC_URL

These commands create signer1_signedTx.json and signer2_signedTx.json, which contain the signatures from ms1 and ms2, respectively.

3. Combine Signatures

Combine the signatures into a single transaction file:

seid tx multisign unsigned-tx.json ms1ms2 signer1_signedTx.json signer2_signedTx.json > signedTx.json

This command merges the individual signatures into a single transaction file named signedTx.json.

4. Broadcast the Multi-Sig Transaction

Finally, broadcast the signed multi-sig transaction to the network:

seid tx broadcast signedTx.json

This command sends the combined, signed transaction to the Sei blockchain for processing.

Summary

By following these steps, you can set up and use multi-sig accounts on the Sei blockchain. This process enhances security by requiring multiple signatures for transaction approval, reducing the risk of unauthorized transactions. Multi-sig accounts are particularly useful for managing shared assets and ensuring that multiple parties must agree before any significant action is taken.