The team behind BitVMX are announcing today the first complete optimistic proving system available on Bitcoin.
The first implementation means that BitVMX isn’t just an idea on paper anymore—it’s a working version that developers can now use and test to build trustless bridges, games, and financial tools. Ultimately with BitVMX you can now compute anything on Bitcoin.
The execution transaction record is available on Bitcoin mainnet. It corresponds to the “Execution Challenge” and it is the first implemented proof followed by 11 others. This is a major milestone for the BitVMX project led by RootstockLabs and Fairgate, paving the way for the development of UNION, the world’s most secure and trust-minimized bridge to Bitcoin.
Components and Features of the Implementation
This implementation consists of two main components:
- A virtual RISC-V CPU to generate execution traces.
- A protocol builder library to create the challenge-response game, track it on the blockchain by reacting to counterparty messages, and publish the necessary scripts to automatically expose any malicious party.
The system validates the execution trace of an arbitrary program on Bitcoin (including 12 distinct challenges) under specific constraints. The program must:
- Be compiled to RISC-V,
- Accept a single input string (with no length limitation), and
- Complete execution in no more than 4 billion steps
Why Is This Important
BitVMX’s implementation represents the first complete optimistic proving system for Bitcoin with key innovations such as:
- On-chain Verification: Programs are validated on top of the Bitcoin blockchain mainnet, ensuring public and decentralized execution.
- Expanded Capabilities: By verifying arbitrary computations, BitVMX broadens Bitcoin’s utility beyond financial transactions to include computational tasks.
- Optimized Efficiency: The use of hash chains and n-ary search techniques reduces computational overhead, making it cost-effective.
What’s Next
While the implementation is not yet production-ready, this marks the first complete optimistic proving system available on Bitcoin, enabling anyone to start using it today. The code has been containerized with Docker for easy local execution.
Soon, the team will release a full demonstration of the protocol, showcasing the optimistic verification of a game on Bitcoin for the first time!
Stay in the know
To stay updated about the research and innovations regarding BitVMX, make sure to follow RootstockLabs on X or join the official BitVMX Builders telegram group to follow and contribute to the project’s progress.
Recommended reading
The first idea of Bitcoin Virtual Machine (BitVM) was brought by Robin Linus in October 2023, and has improved significantly since.
Explore the concept of BitVM and how it led to the discoveries in BitVMX in this series of research articles: