Bitcoin researchers are polishing a new open-source framework called BitVMX, which promises to allow complex applications and functions to be built and executed securely on Bitcoin’s base layer.

BitVMX, inspired by Robin Linus’s BitVM project, is backed by RootstockLabs, a major Bitcoin layer-2 protocol. The project aims to create an open-source, peer-reviewed, sidechain-agnostic framework for developing Bitcoin-based programs.

Cointelegraph spoke exclusively to RootstockLabs chief scientist Sergio Demian Lerner to unpack details of the BitVMX project and its potential impact on the Bitcoin ecosystem. The project is set to be officially unveiled at the Bitcoin++ Austin conference along with the publication of its white paper.

Lerner is best known for his research exploring patterns to identify what hardware Satoshi Nakamoto used to mine in the early days of Bitcoin, which Cointelegraph Magazine covered in 2021.

BitVMX wants to power programs on Bitcoin

On a technical level, BitVMX allows funds to be locked in an unspent transaction output (UTXO) with a spend condition that depends on the result of a program’s execution. Lerner said a program must be defined when the UTXO is created, but the program input does not need to be.

The scientist said the possibilities of the framework are broad and have the potential to power a variety of applications and functions:

“The incredible thing about BitVMX is that it essentially allows developers to run anything on Bitcoin, even Linux.”

Lerner said that BitVMX could power bridges to Bitcoin that allow the unilateral flow of BTC between the main chain and sidechains like Rootstock, where it can then be used to interact with decentralized applications (DApps) and other smart contracts.

Related: Bitcoin needs DeFi, consumer apps for mass adoption — L2 devs

Another use case would be building aggregator oracles that collect and verify data from various sources and store them on the Bitcoin network in an automated and decentralized way.

BitVMX will also support Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zk-SNARK) and Zero-Knowledge Scalable Transparent Argument of Knowledge (zk-STARK) verifiers directly on Bitcoin. This promises to open up new applications such as zero-knowledge contingent payments and autonomous bug bounty programs.

Bitcoin L2 criticisms

The Bitcoin community has been vocal about the increased affinity marketing ploys by startups promoting Bitcoin L2s that claim to operate natively on-chain.

Lerner stressed that BitVMX is not associated with any token sale and that the framework allows the creation of secure and more decentralized bridges that don’t rely on collateralization in foreign tokens.

The computer scientist also said that Rootstock Labs believes in simple criteria to define what constitutes a Bitcoin L2:

“It must use BTC as its native asset and as a settlement mechanism to enforce transactions and demonstrate a functional dependence on Bitcoin. Everything else is just affinity marketing.”

Lerner added that duplicitous projects claiming to be built on Bitcoin have marred every bull market. He adds that users should stick to battle-tested solutions like the Lightning Network, Liquid and Rootstock rather than “risking their sats on untested or unknown solutions with deep pockets and shiny marketing campaigns.”

Shifting the narrative for Bitcoin’s functionality

The BitVMX project openly credits the foundational work of Robin Linus’ BitVM framework. It looks to build on the theoretical approach of BitVM, which uses a complex combinatorial logic circuit approach relying on large Merkle trees for gate-level verification.

Instead, BitVMX touts a streamlined approach by executing central processing unit instructions directly using Bitcoin script opcodes. Lerner says this makes it better suited for real-world applications and unlocks use cases such as running sidechain light clients and verifying using zk-SNARKs.

The chief scientist explained that the framework brings disputable computation to Bitcoin in an “efficient and secure way,” which enables a range of new use cases.

Lerner briefly unpacked the paradigm of disputable computation. No computation is performed on-chain if all parties agree on a computation result.

However, if a party disagrees, an on-chain interaction begins to solve the dispute formally and efficiently. The worst-case scenario leads to a single disputed gate, wire or computation step being verified on-chain.

Related: Bitcoin L2 tokens surge double digits as BTC notches 25-month high

Lerner envisions BitVMX inspiring a new wave of Bitcoin builders by broadening the network’s functionality. He highlighted the framework enabling more complex spending constraints for Bitcoin’s base layer.

The computer scientist added that Bitcoin’s scripting language lacks key opcodes that could make BitVMX cheaper and more efficient.

“It will no longer be a question of should Bitcoin be able to do X?, but “how efficiently can Bitcoin do X,” Lerner said.

A shifting narrative could also accelerate changes to Bitcoin and the potential to bring back opcodes, including OP_MUL or OP_CAT.

Magazine: The value of a legacy: Hunting down Satoshi’s Bitcoin