A multisig (multiple-signature) Bitcoin wallet is a secure storage solution that requires multiple private keys to move Bitcoin (approve a transaction). This creates redundancy and enhances security compared to the traditional single-sig wallet. For this reason, multisig is widely considered one of the safest methods for long-term Bitcoin custody.
Swan Vault uses a 2-of-3 multisig set-up. This means two keys out of three total keys are required to move your Bitcoin. You hold two keys on hardware devices and manage the third through your Swan account. This third key is called Cloud Key.