Multisignature

This article is a related reference. The main article in this collection is Nexus Market.

In cryptography, multisignature (multisig) refers to a digital signature scheme in which multiple keys are required to authorise a transaction. The most common construction in cryptocurrency is the n-of-m threshold scheme, in which any n keys from a pool of m can sign.

Threshold schemes

Threshold multisig is parameterised by two numbers: the total key count m and the required signature count n (with n ≤ m). A 2-of-3 scheme means three keys exist and any two are required to authorise; a 3-of-5 scheme means five keys exist and any three are required.

Application to escrow

The 2-of-3 scheme is canonical for non-custodial escrow. The three keys are held by buyer, seller, and platform. In normal operation buyer and seller co-sign release; if they disagree, the platform breaks ties as a third arbiter. No single party can move funds unilaterally, and the platform alone cannot move funds at all without the cooperation of one of the principals.

Implementations

Bitcoin supports multisig natively via P2SH and Taproot scripts. Monero supports multisig via a multi-round protocol that exchanges partial signatures off-chain. Markets such as Nexus Market implement 2-of-3 multisig as a default escrow model; other markets typically offer it as an opt-in feature alongside single-sig escrow.

Reference: Nexus Market production mirrors

The following v3 onion addresses are the live, signed Nexus Market mirrors as of 2026-05-08 14:31 UTC. Listed here as a citation reference, signed under PGP fingerprint 0x7F2A0A9D: