BNB Chain Implements zk-Fault Proof for opBNB
BNB Chain has recently introduced zero-knowledge (zk) fault proofs to enhance the performance and robustness of the blockchain. This development aims to reduce challenge periods and improve operational efficiency, as detailed on the BNB Chain Blog.
Understanding zk-Fault Proof
Optimism initiated a Foundation Mission Request last year to develop the Op Stack Zero Knowledge Proof (ZKP) for validating fault-proof programs. The ZKP’s primary goal is to expedite the challenge period while simplifying verification processes by funding proposals from various organizations.
- Risc Zero, O(1) Labs, and the ETH Storage team were funded by Optimism to compile fault-proof programs into generic instruction sets like RISCV, WASM, or MIPS.
- These instructions are verified using zkVMs such as zkRISCV, zkWASM, or zkMIPS, contrasting with the typical custom circuit approach.
Development and Integration Process
Recently, Polygon Zero developed a highly efficient type1 zkEVM, meeting BNB Chain’s criteria for tailoring a custom circuit for opBNB’s fault-proof program. Thus, BNB Chain created a proof of concept (PoC) based on Polygon Zero’s type1 zkEVM to demonstrate the advantages over the generic VM approach.
- The current fault-proof design for Optimism comprises off-chain and on-chain components that incur high gas costs and make the system prone to censorship attacks.
- The zk-fault proof intends to streamline the process, enabling challengers to submit a single on-chain transaction, thus reducing gas costs and shortening the challenge period.
Architecture of zk-Fault Proof
The zk-fault proof design involves several critical components:
- Optimism Block Execution Circuit: Processes L2 blocks based on the Optimism state transition protocol.
- Optimism Block Derivation Circuit: Derives L2 blocks from L1 data, ensuring the correctness of the derived block.
- Fault Proof Circuit: Validates the execution and derivation proofs for consistency.
- zkFaultProofVerifier Contract: Located on the L1 chain to validate the ZK fault proofs submitted by challengers.
Challengers can generate a zk-fault proof for disputed L1 blocks and submit it to the zkFaultProofVerifier contract for verification, thus enhancing the overall system security.
Performance Analysis
BNB Chain conducted performance tests comparing the opBNB custom circuit with Zeth developed by Risc Zero, with the former showcasing superior efficiency. The custom circuit required significantly fewer ZK cycles and operated 5-6 times faster than Zeth, presenting a cost-effective solution for opBNB.
Future Roadmap
The ongoing development of the type1 zkEVM includes features like continuations to enhance proof generation efficiency. BNB Chain plans to contribute to these enhancements, expecting substantial performance improvements for the opBNB custom circuit approach.
- Future tasks include implementing additional components like the block derivation circuit, fault-proof circuit, and the zkFaultProofVerifier contract for Optimism or opBNB.
- Upon completion, the opBNB team aims to enhance the security and performance of the multi-proof system by contributing their work to the Optimism ecosystem.
Hot Take: Enhancing Blockchain Performance 🚀
As a savvy crypto enthusiast, the integration of zk-fault proofs by BNB Chain signifies a significant step towards optimizing blockchain performance. With a focus on efficiency, security, and cost-effectiveness, this innovative approach is poised to transform the landscape of blockchain operations, ensuring a seamless and robust user experience. Stay tuned for further developments in the realm of fault-proof programs and their impact on enhancing blockchain functionality!