Multi-party computation (MPC)

MPC is a branch of cryptography that dates back to Andrew Yao's millionaires' problem in 1982: how can two people find out who is richer without revealing their wealth? Protocols split secret data into shares and let participants perform calculations on them jointly, so that only the agreed output is revealed. No participant, and no trusted third party, ever sees the full inputs.

In crypto, MPC's best-known application is key management. Private keys are generated and used in distributed form through threshold signature protocols, so no single device holds the whole key; this underpins MPC wallets offered by custodians and consumer apps. MPC also appears in trusted setup ceremonies, private order matching, sealed-bid auctions and some privacy-preserving DeFi and identity designs.

MPC protocols are complex, need several rounds of communication and rely on careful implementation; bugs can leak secrets. Security usually assumes that not all parties collude, so the real guarantees depend on who holds the shares and how independent they are. Marketing often uses MPC loosely; checking the threshold, the parties and audits matters more than the label.