Multisig is short for "multisignature." Multisig refers to having multiple private keys for a single wallet.
Most wallets are considered single-signature wallets and only require one signature to send a transaction.
Multisig wallets require multiple signatures be applied before the transaction is able to be sent.
By using multisig, it ensures that your funds are not lost if you lose one of your keys. Likewise, if an attacker compromises one of your keys, your funds are not stolen.
The Casa app features a multisig vault for most plan levels. In the 3-key vault, three keys protect your funds, but you only need two to send them. In the 5-key vault, five keys protect your funds, but you only need three to send them. A lost key doesn't mean lost funds, since you still have keys left.
Why should I use multisig?
With multisig, if you do lose a key or have one stolen, you can swap it out for a new one. You can use your remaining keys either to set up a new vault with a new third key and move your funds to it (BTC), or to update the smart contract to reflect a new key (ETH). Casa walks you through it all, step by step.
Casa vault options
Can has two different multisig vault options depending on your needs. You can learn more about them below: