Bitcoiner drops BitVM paper — bringing Ethereum-like contracts to Bitcoin

cointelegraph.com:

A Bitcoin developer has proposed a new way to bring more expressive off-chain smart contracts to Bitcoin (BTC) without needing a soft fork.

Announced in an Oct.9 white paper titled “BitVM: Compute Anything on Bitcoin” by ZeroSync’s project lead Robin Linus, BitVM enables Turing-complete Bitcoin contracts without altering Bitcoin’s consensus rules.

"Any computable function can be verified on Bitcoin"https://t.co/Itf9UHos0C pic.twitter.com/CLQv49Ydsg

A Turing Complete system is one which can theoretically provide an answer to any computational problem.

With BitVM, the “logic” of Bitcoin contracts would be executed off-chain but verification would be made on Bitcoin — similar to Ethereum’s optimistic rollups.

BitVM’s architecture is based on fraud proofs and a challenge-response model where a “prover” can make claims and a “verifier” can perform a fraud-proof to punish the prover when false claims are made.

Linus explained that Bitcoin, in its current form, is limited to basic operations, such as signatures, timelocks, and hashlocks — but that can now be broadened with BitVM, which Linus says can compute a host of interesting applications.

“Additionally, it might be possible to bridge BTC to foreign chains, build a prediction market, or emulate novel opcodes,” said Linus.

Linus said a limitation of the model is that it is limited to a two-party setting with a prover and a verifier and that a significant amount of off-chain computation and communication is needed to execute programs.

Linus said the next “milestone” is to fully implement the BitVM in addition to Tree++ — a high-level programming language to write and debug Bitcoin contracts.

BitVM is enabled by the Taproot soft fork which took place in November 2021.

Linus cited