Why did BNB Chain launch the new Layer2 network opBNB?

Author: Nianqing, bayemon.eth, ChainCatcher

Last night, BNB Chain announced the launch of the opBNB testnet, which is an L2 scalability solution compatible with the Ethereum Virtual Machine (EVM) based on the OP Stack. It is reported that opBNB will support over 4,000 transactions per second, with an average cost of less than $0.005 per transaction. The mainnet is expected to launch in the third quarter of this year.

As early as April this year, BNB Chain mentioned in its first-quarter technical roadmap update that it planned to launch the opBNB testnet in mid-May and the zkBNB mainnet on June 1. Clearly, with the delay of the opBNB testnet, the zkBNB mainnet may also be launched later.

Why is BNB Chain launching opBNB at this juncture?

As crypto giants like Coinbase and ConsenSys are laying out their Layer 2 strategies, is opBNB Binance's response in the Layer 2 arena? In fact, BNB Chain launched the zkBNB testnet last September, but it is well known that while zk technology has great potential, its development difficulty and challenges in achieving full EVM compatibility have slowed the progress of the zkBNB ecosystem.

If the launch of opBNB is intended to respond to competition, then BNB Chain's biggest threats come from L2 solutions like Arbitrum and Optimism. According to DefiLlama data, Ethereum still dominates the public chain competition, with BSC's TVL at $3.35 billion ranking third, but the gap with Arbitrum is gradually narrowing.

BNB Chain's Senior Solutions Architect Arnaud Bauer stated in an interview with The Block that the reason for launching opBNB is that zkBNB is not EVM compatible, and EVM compatibility is crucial for further ecosystem expansion and easier application deployment for developers.

So, what is the functional positioning of opBNB within the entire BNB Chain ecosystem?

Currently, the BNB Chain ecosystem includes Layer 1 chain BSC, BSC application sidechain, storage chain BNB Greenfield, and Layer 2 chains zkBNB and opBNB.

This article will systematically review the history of BNB Chain's scalability and the unique functions and positions of each chain within its ecosystem.

Binance Smart Chain (BSC)

Binance Chain is the starting point of the entire BNB ecosystem. On April 18, 2019, the mainnet of Binance Chain officially launched, marking the early development phase of Binance Chain in 2019, which attracted some attention and users through its mainnet and key components like Binance DEX.

To further expand the functionality of the ecosystem, Binance launched Binance Smart Chain (BSC) in 2020. BSC is an Ethereum Virtual Machine (EVM) compatible smart contract platform that provides developers with a technical environment to build DApps. In February 2022, Binance Chain was renamed BNB Beacon Chain, and Binance Smart Chain was renamed BNB Smart Chain, evolving into a unified modular system called BNB Chain. When the two blockchains merged, the Beacon Chain became a dedicated layer for governance (staking and voting), while the BNB Smart Chain became a dedicated layer for EVM consensus and execution.

At the beginning of 2022, BNB Chain began its ecosystem expansion journey under its new name and established the goal of developing the MetaFi concept, aiming to become the infrastructure provider for the virtual world economic system.

Currently, BSC operates at approximately 2,000 TPS, with an average transaction cost of about $0.109. According to the crypto data platform RootData, BNB Chain still focuses primarily on DeFi and infrastructure, but there are 163 active gaming projects, which is higher in both proportion and number than other public chains.

Chart ++-++ Rootdata

BSC Application Sidechain (BAS)

At the beginning of last year, amidst the rising narrative of multi-chain and application chains, BNB Chain announced the launch of the BSC Application Sidechain (BAS) and a new version of its cross-chain bridge. A sidechain essentially operates as an independent blockchain separate from the main blockchain (BSC) but is connected to the BSC mainnet through a bi-directional bridge.

BNB Chain aims to create an open platform based on BSC, integrating various public chains with unified standards, and plans to expand large-scale applications in areas such as GameFi, SocialFi, and the metaverse.

Layer 2: zkBNB and opBNB

1. zkBNB

However, cross-chain solutions need to consider security issues. After launching the sidechain, BNB Chain began laying out its Layer 2 strategy. In September last year, the zkBNB testnet went live, with officials stating that the asset security of L2 is higher than that of cross-chain solutions, as it can not only overcome network scalability issues but also facilitate secure communication between BSC and BSC-compatible sidechains. Thus, the zkBNB architecture based on zero-knowledge rollups was introduced.

According to the introduction, zkBNB features include: support for rapid integration of payments and atomic transactions, utilizing innovative built-in AMM exchanges and liquidity pools for DeFi use cases, allowing digital assets to be traded automatically without permission; built-in NFT marketplace and API services; and built-in domain name services.

In terms of security, zkBNB achieves equivalent security to BSC due to the guarantees of completeness and fairness provided by SNARK. Regarding transaction costs and speed, gas fees on zkBNB have been reduced to one-tenth, and it can support hundreds of millions of addresses while processing up to 10,000 TPS simultaneously.

Additionally, zkBNB was designed with chain games and social media projects in mind. At the end of March, the zkBNB NFT marketplace was launched on the testnet, featuring functionalities such as NFT series creation, NFT trading, bidding, and marketplace creation.

2. opBNB

As mentioned earlier, the development difficulty of zkBNB and the challenge of achieving full EVM compatibility led BNB Chain to launch opBNB.

The scalability and EVM compatibility of opBNB significantly optimize the experience for developers in creating and running applications, as well as simplifying the migration and expansion of Ethereum chain applications to BSC. The enhancement of functionality and assurance of security provide more opportunities and innovations for the entire BNB Chain ecosystem.

BNB Greenfield

Another important initiative for BNB Chain this year in terms of scalability is the launch of BNB Greenfield. Greenfield's testnet went live on April 11, providing a scalable and efficient data availability layer for dApp developers, with the mainnet expected to launch in the third quarter of this year.

BNB Greenfield aims to serve as the data and storage layer for the BNB Chain ecosystem, integrating with smart contracts hosted on the BNB chain at launch to support storage needs in gaming and social media. The BNB Greenfield testnet has received support from community development teams such as Amazon Web Services and will continue to use BNB as the native token for staking, trading, and governance.

Ben Zhang, co-founder of the main development team NodeReal, stated in an interview with ChainCatcher that BNB Chain is continuously expanding its block size, and it may currently have the world's largest block, with a very large amount of data that each block can store. Such a massive amount of data urgently requires suitable decentralized storage solutions. Directly adopting solutions like Filecoin and Arweave presents issues with performance, seamless integration, and privacy and access control. In the absence of suitable solutions, BNB Chain decided to build an infrastructure that can provide one-stop services for applications in the on-chain ecosystem, such as gaming and the metaverse.

Related Reading: “Interview with NodeReal Co-founder Ben Zhang: Currently, Few Service Providers Can Truly Reach the Core of 'Web3 Version of AWS'”

Conclusion

After reviewing the formation and expansion of the BNB Chain ecosystem, it is not difficult to see that the launch of each chain in BNB Chain is not coincidental but follows a relatively clear logic and trajectory. Although BSC's performance is already high compared to L1 solutions like Ethereum, from the perspective of its MetaFi and GameFi ecosystem positioning, opBNB seems to be a proactive layout for the next explosion in gaming and social applications, providing developers with more convenience in infrastructure.