Why MPC beats multi-sig.
On-chain multi-sig announces your co-signer set — giving attackers a target list and raising gas costs with every signer added. Threshold MPC produces a single on-chain signature; the chain sees one key, while the key material lives shared across the cohort.
Threshold schemes we ship.
Cohort topologies
Pick the policy that matches your risk. Mix user devices, HSMs, and independent custodians.
2-of-3
Consumer wallet — user + iCloud/Google + recovery service
3-of-5
Treasury — CFO + COO + security + bank HSM + cold backup
16-of-N
Institutional custody — N independent co-signers, large-threshold quorum
t-of-n with roles
Policy-aware — trader can sign spot, CFO required for withdrawal
Protocol properties
What CGGMP21 gives you — and what to watch for.
UC-secure
Universally composable — security holds under arbitrary concurrent execution. Proven in the standard model.
Identifiable abort
If a cohort member cheats during signing, the protocol aborts and cryptographically names the attacker. No silent compromise.
Non-interactive refresh
Rotate shares without changing the public key. Compromised shares become useless at the next epoch.
Biased-range ZK
Paillier ciphertexts proven in range via low-overhead range proofs. Keeps signing latency < 300ms.
Batch-verifiable
Aggregate hundreds of threshold signatures into a single batch proof for audit.
Corona bridge
Same cohort can sign classical ECDSA and post-quantum ML-DSA. Migrate without redistributing shares.
Where it plugs in.
Lux MPC is the engine beneath our non-custodial bank. Every withdrawal, trade, and governance vote traverses a threshold cohort that includes the user device, validator nodes, and HSM-rooted backups.
Open source.
Lux MPC is built on github.com/luxfi/mpc — reviewed by Trail of Bits, formally modeled in Tamarin, and used in production for Lux Network validator keys and custody.
Your keys. Split.
Integrate Lux MPC or run your own cohort with our SDKs.