Multi-party computation custody is the institutional use of a multi-party computation (MPC) wallet to hold digital assets for clients: the signing key is generated as separate shares held by different parties or devices, and transactions are signed jointly without the full key ever being assembled. The main entry explains the wallet technology itself.
The custody term describes the service built around it. A custodian or a firm running its own treasury distributes key shares across its own servers, a client device and sometimes a third party, and combines the cryptography with approval policies, such as limits, address allowlists and a required number of approvers. Most schemes use a threshold signature scheme, so that a set number of shares, rather than all of them, is needed to sign. Shares can be refreshed or reassigned without moving the assets to a new address.
It is one of the main models of institutional crypto custody, alongside hardware security modules and the multi-sig wallet, which enforces multiple approvals on the blockchain itself rather than off it. MPC works across blockchains that lack native multi-signature support, but it depends on the soundness of the vendor's implementation and on the surrounding wallet governance.