Build on Bitcoin adds ZK-proofs in upgrade toward decentralization

July 24 2025, Build on Bitcoin (BOB) introduced a key upgrade that adds ZK fraud proofs to its optimistic rollup framework, marking a major step toward full decentralization and inclusion on L2Beat rankings.

Build on Bitcoin implements ZK fraud proofs

Layer-2 protocol Build on Bitcoin has deployed a zero-knowledge fraud proof system, replacing the traditional dispute resolution methods of optimistic rollups with a faster and more secure ZK-based process.

This change allows network challenges to be resolved in minutes instead of hours or days, significantly reducing friction for participants and lowering the barrier for validators to contribute to securing the network.

The Kailua upgrade targets L2Beat decentralization

BOB co-founder Alexei Zamyatin confirmed that this technical milestone advances BOB to stage 0 in L2Beat’s decentralization framework, with plans to move swiftly toward stages 1 and 2.

L2Beat evaluates decentralization by reviewing features like fraud proof systems, external security councils, and upgrade delays. With the Kailua upgrade delivering a working proof mechanism, BOB now meets a key requirement.

Only two layer-2s ZK.Money v1 and Honeypot PRT have reached stage 2 under L2Beat’s classification. BOB is now positioned to join that shortlist once its security council implementation is complete.

Build on Bitcoin unlocks ZK verification for Bitcoin

Zamyatin also revealed that the upgrade enables BOB to support ZK verification directly on Bitcoin through BitVM. This paves the way for a Bitcoin-native bridge and DeFi infrastructure with smart contracts verifiable on the Bitcoin base layer.

According to Zamyatin, BOB is evolving into a gateway for Bitcoin DeFi, providing secure access to native BTC, programmable assets, and institutional applications.

Bitcoin DeFi ambitions and future outlook

BOB has long positioned itself as the protocol to bring Ethereum-style DeFi to Bitcoin. Zamyatin has previously stated that Bitcoin DeFi will one day surpass Ethereum and Solana, attracting over 300 million users.

With ZK fraud proofs and BitVM-based bridges in progress, BOB’s roadmap aligns with its goal of offering a fully decentralized, Bitcoin-secured layer-2 that scales both DeFi access and smart contract utility.