Multisig keys 🔐
This feature of fetchd allows users to securely control keys in a number of configurations. This involves setting a minimum number of keys required to sign a transaction out of a maximum of N keys, known as a threshold number K.
Creating a multisig key
To create a multisig key, use the following syntax:
# Create a simple multisig key with a threshold of 1 as default fetchd keys add <multisig_key_name> --multisig <list_of_key_names> # Creating a multisig key with a higher threshold, K fetchd keys add <multisig_key_name> --multisig <list_of_key_names> --multisig-threshold <threshold integer K>
Example instantiation of a multisig key: shared business multisig key
Consider a scenario in which three account holders need to collectively authorize transactions. At least two out of the three (K=2) must sign off on each transaction:
# Create the three keys owned by the separate account holders fetchd keys add fred fetchd keys add ted fetchd keys add ned # Create the multisig key from keys above fetchd keys add business_key --multisig fred,ted,ned --multisig-threshold 2
Importantly, remember to retrieve the address of business_key for future use:
fetchd keys show -a business_key
Signing and broadcasting multisig transactions
Transactions must be signed and broadcasted before they can be executed.
In order to sign a multi signature transaction, the transaction itself must not be immediately broadcast. Instead, the key holders must each sign until a minimum threshold K signatures are present.
For this example, we will be performing the transaction on the Dorado (opens in a new tab)
network and therefore will be using atestfet as the denomination, and a gas price of 1000000000atestfet (this should be changed depending on the actual currency and network used).
Example: Multisig transaction
# Create a key to represent a vendor that the business must pay fetchd keys add vendor # Generate a transaction as an output file to be signed by # the keyholders, 'ted' and 'fred' in this example fetchd tx bank send <business_key address> <vendor address> 1000atestfet --gas 90000 --gas-prices 1000000000atestfet --generate-only > transfer.json # you'll get "account <address of business_key> not found" error for missing funds # add funds to <address of business_key> using block explorer or by eg curl -X POST -H 'Content-Type: application/json' -d '{"address":"<address of business_key>"}' https://faucet-dorado.fetch.ai/api/v3/claims # This transaction file (transfer.json) is then made available for # the first keyholder to sign, 'fred' fetchd tx sign transfer.json --chain-id dorado-1 --from fred --multisig <address of business_key> > transfer_fredsigned.json # This is repeated for 'ted' fetchd tx sign transfer.json --chain-id dorado-1 --from ted --multisig <address of business_key> > transfer_tedsigned.json # These two files are then collated together and used as inputs to the # multisign command to create a fully signed transaction fetchd tx multisign transfer.json business_key transfer_fredsigned.json transfer_tedsigned.json > signed_transfer.json # Now that the transaction is fully signed, it may be broadcast fetchd tx broadcast signed_transfer.json # Now display the result of the transaction and confirm that the vendor has # received payment fetchd query bank balances <address of vendor>
It is important to note that this method of signing transactions can apply to all types of transaction, including staking and withdrawal transactions as shown below.
Other multisig transaction examples
Other examples are provided below:
# In order to create a staking transaction using a multisig key # the same process as above can be used with the output file of this command fetchd tx staking delegate <fetchvaloper address> 10000atestfet --from <address of business_key> --gas 200000 --gas-prices 1000000000atestfet --generate-only > stake.json # The following command can also be used to create a withdrawal transaction for the # rewards from staking when using a multisig key - this too must be signed as before fetchd tx distribution withdraw-all-rewards --from <address of business_key> --gas 150000 --gas-prices 1000000000atestfet --generate-only > withdrawal.json