Setting Up a Sui Multisig Account: A Step-by-Step Guide

A step-by-step tutorial for creating a secure multi-signature account on the Sui blockchain

Introduction

Multisig accounts enhance blockchain security by requiring multiple signatures to authorize transactions, reducing single points of failure. In this guide, we’ll set up a 2-of-3 multisig account on Sui — three owners with weighted signatures, requiring combined weight of 3 to execute transactions.

Why Use Multisig Accounts?

More Secure: One compromised key won’t risk funds
Shared Control: No single point of failure
Great for Teams: Ideal for DAO and corporate treasuries
Fewer Mistakes: Multiple signers catch errors

Prerequisites

Sui CLI installed
Basic blockchain knowledge
Some SUI tokens (use faucet for testnet)

Step 1: Creating Owner Accounts

First, we need to create the accounts that will share control of our multisig account.

Open your terminal and run these commands:

sui client new-address ed25519 owner1 
sui client new-address secp256k1 owner2 
sui client new-address secp256k1 owner3

After running these, you’ll get output like this:

╭────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Created new keypair and saved it to keystore.                                                      │
├────────────────┬───────────────────────────────────────────────────────────────────────────────────┤
│ alias          │ owner1                                                                             │
│ address        │ 0x16a4a0747294891f39f8aea795ed9252d25eb7a19ccbdc45059184d08cb298e0                │
│ keyScheme      │ ed25519                                                                           │
│ recoveryPhrase │ mistake empty village thrive predict maze twist define brand repeat craft swallow │
╰────────────────┴───────────────────────────────────────────────────────────────────────────────────╯
╭─────────────────────────────────────────────────────────────────────────────────────────────╮
│ Created new keypair and saved it to keystore.                                               │
├────────────────┬────────────────────────────────────────────────────────────────────────────┤
│ alias          │ owner2                                                                      │
│ address        │ 0xf950e5560f31e0815dad9c4b96e0af94d1528b96aa4324f42887ea9ef03e1fa9         │
│ keyScheme      │ secp256k1                                                                  │
│ recoveryPhrase │ muscle morning tiger trust rail chair invest throw crisp critic photo deal │
╰────────────────┴────────────────────────────────────────────────────────────────────────────╯
╭───────────────────────────────────────────────────────────────────────────────────────────────╮
│ Created new keypair and saved it to keystore.                                                 │
├────────────────┬──────────────────────────────────────────────────────────────────────────────┤
│ alias          │ owner3                                                                        │
│ address        │ 0x4779377e48802c2f2e21950b230d9f4ba1589a9effd4024377161e0463b2cc96           │
│ keyScheme      │ secp256k1                                                                    │
│ recoveryPhrase │ toilet lawn rural wonder taste sight table shrimp pistol capital caught dune │
╰────────────────┴──────────────────────────────────────────────────────────────────────────────╯

Save these addresses in environment variables for easy reference:

owner1_addr=0x16a4a0747294891f39f8aea795ed9252d25eb7a19ccbdc45059184d08cb298e0
owner2_addr=0xf950e5560f31e0815dad9c4b96e0af94d1528b96aa4324f42887ea9ef03e1fa9
owner3_addr=0x4779377e48802c2f2e21950b230d9f4ba1589a9effd4024377161e0463b2cc96

Step 2: Getting Public Keys

We need the public keys for each owner to create the multisig account:

sui keytool list

This shows all your keys with their public keys. Copy the publicBase64Key for each owner:

owner1_pubkey=<OWNER1-PUBLIC-KEY>
owner2_pubkey=<OWNER2-PUBLIC-KEY>
owner3_pubkey=<OWNER3-PUBLIC-KEY>

Step 3: Creating the Multisig Account

Now let’s create our multisig account with weighted signatures:

sui keytool multi-sig-address \
  --pks $owner1_pubkey $owner2_pubkey $owner3_pubkey \ 
  --weights 1 2 2 \ 
  --threshold 3

This creates a 2-of-3 setup where:

Owner 1 has weight 1
Owner 2 has weight 2
Owner 3 has weight 2
Need combined weight ≥ 3 to execute transactions

The command will output your new multisig address:

multisig_addr=<YOUR-MULTISIG-ADDRESS>

Step 4: Funding the Multisig Account

The multisig account needs some SUI to execute transactions. Visit https://faucet.sui.io to fund your multisig account, then verify:

sui client gas $multisig_addr

Step 5: Creating a Transaction

Let’s create our first transaction using the multisig account. We’ll transfer some SUI to another address.

Define the recipient and amount:

RECIPIENT_ADDRESS=0xfe65fb1d1df439982c0e5191151ad3a6dec85d44870435a3380fc65cda6700bb
coin=<GAS-COIN-ID>  # Get this from the gas command above

Create an unsigned transaction:

sui client transfer \
  --to $RECIPIENT_ADDRESS \
  --object-id $coin \
  --serialize-unsigned-transaction

Save the transaction bytes:

txbytes=<YOUR-TX-BYTES>

Step 6: Collecting Signatures

Now we need to collect signatures. Since we need combined weight of 3, let’s get signatures from Owner 1 and Owner 2:

sui keytool sign --address $owner1_addr --data $txbytes
sui keytool sign --address $owner2_addr --data $txbytes

Save both signatures:

sig_1=<OWNER1-SIGNATURE>
sig_2=<OWNER2-SIGNATURE>

Step 7: Combining Signatures

Combine the individual signatures into a multisig signature:

sui keytool multi-sig-combine-partial-sig \
  --pks $owner1_pubkey $owner2_pubkey $owner3_pubkey 
  --weights 1 2 2 
  --threshold 3 
  --sigs $sig_1 $sig_2

Save the combined signature:

multisig_hash=<COMBINED-MULTISIG-SIGNATURE>

Step 8: Executing the Transaction

Finally, execute the multisig transaction:

sui client execute-signed-tx \
  --tx-bytes $txbytes \
  --signatures $multisig_hash

Advanced Features

Different Signature Combinations

With our weighted setup, these combinations work:

Owner 2 + Owner 3 = Weight 4 (✅ Exceeds threshold)
Owner 1 + Owner 2 = Weight 3 (✅ Meets threshold)
Owner 1 + Owner 3 = Weight 3 (✅ Meets threshold)
Any single owner alone = Insufficient weight (❌)

Future Developments

The Sui multisig implementation continues to evolve. Potential improvements include:

Dynamic member management: Add/remove signers without migrating funds
Better UI tools: Graphical interfaces for easier multisig management

Conclusion

Multisig accounts provide essential security for serious blockchain operations. Sui’s implementation with weighted signatures offers flexibility while maintaining security.

Whether you’re protecting personal assets, managing team funds, or securing a DAO treasury, multisig accounts add crucial protection. The setup complexity is a small trade-off for the significant security benefits.

Originally published on Medium.