What is the difference between an MPC wallet and a multisig?
A multisig uses several separate keys, and code on the chain checks that enough of them signed.1,2 An MPC (threshold) wallet splits one key into shares, and enough shares together make one ordinary signature, so the chain sees a single key.3,4
This lesson compares two designs. It does not recommend either one, or any provider of them.
Two ways to need more than one person
Both designs avoid relying on one key. A multisig splits control between several key holders.1 A threshold scheme lets a signature be made without any single part ever holding the whole signing key.3
Multisig: many keys, counted on the chain
In a multisig, each signer signs separately, with their own key or account.4,5 The signatures are checked on the chain.4,2
- On Bitcoin, a k-of-n multisig script puts k signatures and n public keys into the transaction.4
- On Ethereum, a multisig such as Safe keeps its owners and threshold in a contract. The contract checks the signatures.2
So the rules are written in code on the chain. With Safe, every change to the owners or the threshold is recorded on the chain as an event.5
MPC: one key, in pieces
MPC stands for secure multiparty computation.6 NIST, the US standards agency, describes threshold schemes that use MPC to spread trust across several parties.6
The starting point is secret sharing. A key is split into shares, held by different parties.3 The key can be rebuilt from a threshold number of shares, but not from fewer.3
In threshold cryptography, the shares do not even need to be put back together.3 Each party works out its piece of the result without showing the others its share.3 So a signature can be made without any single part ever holding the signing key.3
The result is one normal-looking signature. A threshold signature can be checked with one public key and one signature, however many parties took part.4
What the chain can see
| Point | Multisig | Threshold signature (MPC) |
|---|---|---|
| Public keys on the chain | Several: n on Bitcoin4 | One4 |
| Signatures on the chain | k of them4 | One4 |
| Can outsiders tell several people signed? | Yes: the signatures are in the transaction4 | No: nobody can tell who signed, or that several had to4 |
| Where the k-of-n rule lives | In code on the chain2 | In how the shares are made and used3 |
Trade-offs
- Smaller transactions. On Bitcoin, one signature instead of many makes a transaction smaller, which can cut its fee.4
- Privacy cuts both ways. Nobody can tell who signed, which helps privacy.4 But Bitcoin Optech notes this is a problem when outside auditors need to see which parties signed.4
- A separate record. One fix is an independent log, for example sending all messages between the parties through a logging server.4
- More shares, more targets. NIST notes that using several shares widens the attack surface to cover all of them.3
- Shares can be refreshed. Some schemes re-share the secret from time to time, so shares stolen earlier stop counting.3
- Still being studied. NIST published its first call for multi-party threshold schemes on 20 January 2026.6
- Introduction to smart contracts (multisig contracts). ethereum.org developer docs, page updated 25 February 2026.
- Concepts: owners, threshold, signature verification and transaction flow. Safe documentation.
- NISTIR 8214: Threshold Schemes for Cryptographic Primitives. L. Brandão, N. Mouha and A. Vassilev, US National Institute of Standards and Technology (NIST), March 2019.
- Threshold signature. Bitcoin Optech (topics).
- How do Safe Smart Accounts work?. Safe documentation (Safe Smart Account overview).
- Multi-Party Threshold Cryptography (MPTC) project. US National Institute of Standards and Technology (NIST), Computer Security Resource Center.
General education built from the publicly available sources listed above. Not financial, legal, tax or investment advice. Naming a company, project or regulator is not an endorsement either way. Last checked 2026-10-22. Terms and disclaimer.