According to Odaily, Arbitrum has integrated with BitcoinOS (BOS) to introduce its Layer 2 scaling solution to the Bitcoin network. This integration allows Arbitrum One to function as a hybrid rollup, leveraging Bitcoin's security and Ethereum's scalability. By utilizing BitcoinOS (BOS), the network gains trustless cross-chain capabilities and Bitcoin finality assurance through the BOS Grail bridge. The development team believes this reduces counterparty risk compared to existing Bitcoin interoperability solutions. The BOS framework employs zero-knowledge proofs (ZK) to enable Bitcoin transactions to interact with other ecosystems. This integration is expected to provide Bitcoin holders with broader access to DeFi applications and smart contracts.