What are you building?

tBTC is a decentralized, permissionless, and censorship-resistant Bitcoin bridge. However, Bitcoin holders cannot leverage their BTC in the Optimism ecosystem in a trust-minimized way.

With the launch of tBTC v2 3 it’s now possible to bridge Bitcoin to Ethereum in a trust-minimized way. We propose a solution to bridge tBTC to Optimism in the near-term.

To make the user experience of bridging tBTC from L1 to Optimism as seamless as possible and to avoid the proliferation of non-compatible wrapped tBTC tokens resulting in fragmented liquidity, Threshold will implement a minter contract that delegates restricted minting authority to the native Optimism bridge, along with a short-list of ecosystem bridges (e.g. Wormhole, L0, etc.).

This contract will have a minting authority for TBTC on Optimism but can be paused by any one of n tBTC guardians (Threshold tBTC Guardians - General - Threshold Network), allowing avoidance of contagion in case of a chain- or bridge-specific incident.

Later, Threshold may implement the ability to mint tBTC directly from Bitcoin on Optimism, without Ethereum L1 as an interim step, if it is sensible to do so.