tBTC relaunches, renewing effort to create a trustless Bitcoin-to-Ethereum bridge

tBTC, an open-sourced project from Keep, Summa, and the Cross-Chain Group, relaunched on Monday after a paused launch in May.

tBTC allows a 1-to-1 exchange of Bitcoin for TBTC, which is an ERC-20 token that can be used in Ethereum DeFi apps. According to a statement from Keep, tapping liquidity between Bitcoin and DeFi apps is required for the long-term growth of the cryptocurrency economy. But to do so, the Bitcoin, Ethereum bridge must be safe and reliable, which is what tBTC hopes to provide.

Previously, tBTC had to pause its May launch after the team found a “a significant issue in the redemption flow of deposit contracts was identified that put signer bonds at risk in certain situations,” tBTC said in a statement. Now, one BTC held in reserve fully backs and matches every TBTC token.

tBTC uses a random beacon to select “signers” responsible for depositing BTC so that the company can remain trustless. Those who exchange TBTC to BTC face no intermediary sign-off. Users must perform three steps to mint TBTC on the tbtc.network and track their Bitcoin.

Those behind the project said that tBTC has been the subject of two additional audits following one that took place in March. "tBTC has been tested rigorously and has undergone an unprecedented three audits. tBTC concluded its first security audit, by ConsenSys, in March. In June, we concluded a second audit by Trail of Bits, and in August we completed a new Bitcoin audit," they wrote, writing later:

"The alpha launch of tBTC — known as rc.0 — went live on mainnet in May after a public audit from ConsenSys Diligence. While user funds were never at risk, our team discovered an issue and immediately paused accepting new funds while the problem was addressed. rc.1 resolves the issue, and launched with unprecedented security measures in place. tBTC, which uses the highest standard of cryptography, threshold ECDSA, is fully audited, open-source, and with protections for funds."