Multisig

Multisig, short for multisignature, is a bitcoin arrangement that requires signatures from multiple keys to spend funds, defined as m-of-n: for example, 2-of-3 means any two of three designated keys must sign. The keys can be held on different devices, in different places, or by different people, so no single key can move the money alone.

Why it matters

Multisig removes single points of failure from self-custody. With a 2-of-3 setup, a thief who compromises one key gets nothing, and an owner who loses one key can still recover funds with the remaining two. This makes it the standard for securing large amounts: businesses use it to require sign-off from multiple officers, collaborative custody services hold one key while the client holds two, and inheritance plans distribute keys among family members and lawyers. The cost is complexity, since managing several keys, their backups, and the wallet configuration demands more care than a single-signature wallet.

In the gold vs bitcoin debate

Nothing in the physical world replicates multisig. Gold can be split across several vaults, but each portion is then fully spendable by whoever holds it, and recombining control requires physically gathering the metal. Bitcoin lets an owner define spending rules in software: any two of three keys on separate continents can move the full balance, instantly, without the keys ever being in one place. For proponents this programmability of custody is a categorical advance over physical bearer assets; for gold holders it is one more layer of technology that has to work perfectly.