Threshold Network (tBTC)
Decentralized BTC-pegged token on Ethereum-compatible chains. Uses threshold signatures with randomly selected signers rather than single custodian (like wBTC) or fixed federation.
Architecture
- Random signing groups of 100 nodes, drawn by sortition from the staked operator pool.
- t-of-n threshold ECDSA — 51-of-100.
EcdsaDkgValidator.solin keep-network/keep-core pinsgroupSize = 100,groupThreshold = 51,activeThreshold = 90; those constants are unchanged onmainas of September 2026. - Slashing: malicious nodes lose stake.
- Native token: T (Threshold).
Peg-in (BTC → tBTC)
- User submits SPV proof of BTC deposit to Ethereum tBTC contract.
- Random signing group verifies, mints tBTC.
- tBTC = ERC-20 on Ethereum, redeemable 1:1 for BTC.
Peg-out (tBTC → BTC)
- User submits redemption request on Ethereum.
- Signing group signs BTC release tx.
- BTC sent to user.
Compared to wBTC
| Aspect | tBTC | wBTC |
|---|---|---|
| Custody | Decentralized signers | BitGo (single custodian) |
| Trust | Threshold + slashing | Trust BitGo |
| Decentralization | Higher | Centralized |
| Status | Live | Live |
| TVL | ~$333M | ~$8.8B |
TVL figures are DefiLlama, 16 September 2026: wBTC is roughly 27x tBTC.
Compared to BitVM-based bridges
| Aspect | tBTC | BitVM2 (Citrea) |
|---|---|---|
| Verification | Threshold signers | Optimistic challenge |
| Liveness | Signers must be online | Challengers must be online |
| Withdrawal time | Quick (signing) | 24+ hours challenge window |
| Audit complexity | Standard | Complex |
Downstream: Mezo
Mezo, the Bitcoin-first chain from the same shop (Thesis), mainnet 28 May 2025, is a significant tBTC consumer: it bridges BTC in over tBTC, uses BTC for gas, and collateralises its MUSD CDP stablecoin with it. Two DefiLlama figures for scale, both 15 September 2026 — tBTC protocol ~$336.0M, Mezo chain ~$71.7M (not all of which is tBTC). So tBTC's signer assumptions now sit underneath a stablecoin as well as under EVM DeFi positions. See mezo/SKILL.md.
Use cases
- Bringing BTC to Ethereum DeFi (lending, AMMs).
- Cross-chain composition between BTC + EVM ecosystems.
- Collateral for Bitcoin-native credit markets (Mezo / MUSD).
Limitations
- Threshold trust — though distributed, still trust-based.
- Random group rotation complexity.
- Smaller TVL than wBTC despite better decentralization (UX).