A Bitcoin developer named Robin Linus has proposed a new method to enhance off-chain smart contracts on the Bitcoin network without the need for a soft fork. Linus introduced his concept, called BitVM, in an Oct. 9 white paper titled “BitVM: Compute Anything on Bitcoin.” This new approach would enable Turing-complete Bitcoin contracts without making any changes to the consensus rules of the network.
BitVM’s design is similar to Ethereum’s optimistic rollups, where the logic of Bitcoin contracts would be executed off-chain, while the verification would take place on the Bitcoin network itself. It is built upon fraud proofs and utilizes a challenge-response model. A “prover” can make claims, and a “verifier” can perform a fraud-proof to penalize the prover for false claims.
Currently, Bitcoin’s functionality is limited to basic operations such as signatures, timelocks, and hashlocks. However, with BitVM, Linus believes that Bitcoin can support a wide range of applications including games like Chess, Go, or Poker, as well as the verification of validity proofs in Bitcoin contracts. He also mentioned the potential to bridge Bitcoin to other chains, create prediction markets, or emulate novel opcodes.
Linus did acknowledge a limitation of the model, stating that it is limited to a two-party setting with a prover and a verifier. The execution of programs would require a significant amount of off-chain computation and communication.
The next milestone for Linus is to fully implement BitVM, along with Tree++, a high-level programming language specifically designed to write and debug Bitcoin contracts. It’s worth noting that BitVM is made possible by the Taproot soft fork, which took place in November 2021.
Several members of the Bitcoin community have responded to the BitVM proposal. Eric Wall, a prominent Bitcoiner, expressed his excitement about the concepts outlined in the white paper and looks forward to real-world experiments based on BitVM. Bitcoin analyst Dylan LeClair also praised the proposal, while Bitcoin Core contributor Adam Back urged caution and suggested that people shouldn’t get too excited just yet.
One builder in the blockchain space, “dotta,” pointed out that there is already a proof-of-concept of BitVM available on GitHub. Another user, Sam Parker, addressed concerns among Bitcoin maximalists by explaining that BitVM is an opt-in feature and won’t require users to lock their coins into Turing complete contracts.
Overall, BitVM is seen as an important development that could push Bitcoin’s capabilities forward and potentially have an impact on its price in the next bull market. Cointelegraph reached out to Robin Linus for further comment but has yet to receive a response.