Confium Threshold
Confium Threshold is the threshold-signing product: replace a single private key with T-of-N distributed shares. No single party can sign alone. Compromising any T-1 parties doesn’t compromise the key.
Algorithms
| Algorithm | Curve / Group | Rounds | Status |
|---|---|---|---|
| CMP20 | P-256 | 3 | Shipped |
| GG18 | P-256 | 4 | Shipped (legacy; prefer CMP20) |
| FROST | P-256 | 2 | Shipped |
| FROST | Ed25519 | 2 | Shipped |
| MuSig | Schnorr | 2 | Skeleton |
| BLS | BLS12-381 | 2 | Skeleton |
| Threshold ElGamal | P-256 | N/A (encryption) | Shipped |
Crates
confium-tc-core— session primitives, share interface, registryconfium-tc-keys— key lifecycle, HSM/KMS, BIP-32confium-coordinator— multi-round orchestration serviceconfium-tc-cmp20— CMP20 threshold ECDSAconfium-tc-gg18— GG18 threshold ECDSAconfium-tc-frost-p256— FROST over P-256confium-tc-frost-ed25519— FROST over Ed25519confium-tc-bls— Threshold BLS (skeleton)confium-tc-elgamal-p256— Threshold ElGamal encryptionconfium-signerd— production signing daemon
Concepts
These topics are specified in the specs repo:
- Threshold signing fundamentals
- Distributed key generation (DKG)
- Share refresh & proactive security
- Reshare: changing T or N without re-keying
Multiplicative-to-Additive (MtA) via Paillier is described in the
CMP20 spec and implemented
in confium-crypto-vss::paillier.
How-to
Practical recipes live in the Cookbook:
- Threshold-sign-with-CMP20 — 2-of-3 sign ceremony
- Refresh shares without re-keying — Herzberg proactive security
- Backup and restore shares — disaster recovery
- Deploy signerd on Kubernetes
- Monitor Confium with Prometheus
Reference
- Rust API
- Threshold session spec
- CMP20 spec
- GG18 spec
- FROST-P256 spec
- FROST-Ed25519 spec
- ElGamal-P256 spec
In this section
- Concepts — threshold signing, DKG, share refresh, MtA
- How-to — run a local DKG, sign a message, refresh shares
- Reference — CLI, crates
Cross-links
- Confium architecture — engine, plugin loader
- Bindings parity matrix — what’s available per language
- Confium Threshold on the website