The app works by leveraging crypto’s multisignature, or “multisig” functionality. Multisig is when a user needs more than one signature to spend crypto funds. A user holding bitcoin (BTC) in a Casa wallet for example, could use a “2-of-3” multisig, meaning, three private keys exist, but only two are required to spend funds. If the user loses one key, they can still access their funds with the remaining two (one of which is entrusted to and securely stored by Casa).
Source: https://www.coindesk.com/tech/2022/11/30/bitcoin-custody-firm-casa-to-add-ethereum-support/?utm_medium=referral&utm_source=rss&utm_campaign=headlines