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](https://docs.sui.io/guides/developer/getting-started/sui-install) installed - Basic blockchain knowledge - Some SUI tokens ([use faucet for testnet](https://faucet.sui.io/)) ## 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: ```bash 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: ```bash ╭────────────────────────────────────────────────────────────────────────────────────────────────────╮ │ 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: ```bash 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: ```bash sui keytool list ``` This shows all your keys with their public keys. Copy the publicBase64Key for each owner: ```bash owner1_pubkey= owner2_pubkey= owner3_pubkey= ``` ## Step 3: Creating the Multisig Account Now let’s create our multisig account with weighted signatures: ```bash 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: ```bash multisig_addr= ``` ## Step 4: Funding the Multisig Account The multisig account needs some SUI to execute transactions. Visit [https://faucet.sui.io](https://faucet.sui.io) to fund your multisig account, then verify: ```bash 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: ```bash RECIPIENT_ADDRESS=0xfe65fb1d1df439982c0e5191151ad3a6dec85d44870435a3380fc65cda6700bb coin= # Get this from the gas command above ``` Create an unsigned transaction: ```bash sui client transfer \ --to $RECIPIENT_ADDRESS \ --object-id $coin \ --serialize-unsigned-transaction ``` Save the transaction bytes: ```bash txbytes= ``` ## 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: ```bash sui keytool sign --address $owner1_addr --data $txbytes sui keytool sign --address $owner2_addr --data $txbytes ``` Save both signatures: ```bash sig_1= sig_2= ``` ## Step 7: Combining Signatures Combine the individual signatures into a multisig signature: ```bash 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: ```bash multisig_hash= ``` ## Step 8: Executing the Transaction Finally, execute the multisig transaction: ```bash 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](https://medium.com/@gunaon2509/setting-up-an-sui-multisig-account-a-step-by-step-guide-fbb71185a79d).*