Announcing B² Hub: Unlock the Bitcoin DA Layer
B² Network has been a pioneering solution for verifying zero-knowledge proofs (zk proofs) on Bitcoin since its launch. Back in the early days, when we were designing the infrastructure of the B² Network, this was our most significant challenge. With the introduction of B² Hub, B² Network can now share the DA layer with other Bitcoin rollups, thereby realizing Bitcoin rollup-as-a-service.
ZK proof can’t be verified on Bitcoin directly
The primary reason Bitcoin struggles to verify zk proofs directly lies in its inherent design philosophy and blockchain security.
1. Design Philosophy:
Bitcoin’s design philosophy emphasizes decentralization and security. Thus, Bitcoin has opted for a relatively simple yet secure scripting language, limiting Bitcoin’s smart contract and complex verification capabilities. Zero-knowledge proofs typically involve intricate mathematical operations that may exceed the capabilities of Bitcoin’s scripting language.
2. Computational and Storage Resources
Verifying zero-knowledge proofs requires significant computational and storage resources. The design of the Bitcoin network implies that nodes must have sufficient resources to verify all transactions, but directly verifying zk proofs may surpass the performance requirements of network nodes. This design ensures Bitcoin’s decentralization and security but makes it challenging to accommodate more complex verification mechanisms.
3. Network Consensus:
Bitcoin’s consensus algorithm (proof-of-work) is designed to ensure that all nodes reach consensus on transaction order and state. Introducing complex verification mechanisms may lead to consensus issues, as different nodes may achieve varying degrees of proficiency in verification, affecting the overall security of the network.
Current Bitcoin zk rollup solutions simply upload zk proofs onto the Bitcoin blockchain through inscription, lacking the crucial process of verification on the Bitcoin network. This absence of verification poses potential security issues. Consider a scenario where a rollup provider initiates a transaction from your wallet, and if the result is not verified by Bitcoin, your wallet could be emptied without detection.
B² Network innovatively uses zk proof commitment to verify the proofs on Bitcoin
After months of exploration, we have finally devised a method to verify zk proofs on Bitcoin. The workflow is as follows:
1️⃣ The zk proofs’ verification commitments are transformed into taproots.
2️⃣ B² submits the taproots onto the Bitcoin blockchain.
3️⃣ Challengers (Validators), incentivized by BTC rewards, can raise challenges if any issues are detected.
4️⃣ The zk proofs undergo verification on the Bitcoin network.
This process operates under the B² Challenge-Response protocol, a mechanism that ingeniously enables B² rollup verification on the Bitcoin blockchain, ensuring that the B² Rollup is as secure as Bitcoin.
The Next: Launching B² Hub and making B² Rollup as a service
The proliferation of Bitcoin rollups is poised to significantly alter the landscape of the Bitcoin ecosystem. We eagerly anticipate witnessing the emergence of more robust applications and innovations within this space. As a result, we have decided to introduce B² Hub, an expansion stemming from both B² Nodes and our Challenge-Response protocol.
How B² Hub Works:
- Any Bitcoin rollup can leverage the B² Hub for verification on the Bitcoin network, saving time and reducing costs.
- B² Hub will compile aggregated batch and proof data into tapscript, submitting the zk proof verification commitment as the taproot to Bitcoin collectively.
The modular DA layer has proven successful and effective in various ecosystems. Currently, we are collaboratively constructing the BTC ecosystem alongside several RaaS participants. We believe that by sharing our solution for verifying zk-proof on Bitcoin, the Bitcoin ecosystem can benefit and undergo accelerated growth.
About B² Network
B² Network is the most Practical Bitcoin Layer-2 Network, building the first EVM-compatible Rollup based on zero-knowledge proof verification commitment on Bitcoin.
