An in-depth interpretation of opBNB, what potential will Layer 2 bring to BNB Chain?

On the evening of June 19, BNB Smart Chain (BSC) announced the launch of a new expansion solution, opBNB, and launched the opBNB test network. In 2020, when the Ethereum network was congested, the launch of BSC provided users and developers with a fast, secure, and low-cost decentralized application environment.
However, with the surge in transaction volume such as GameFi, BSC has also faced network congestion and high gas fees at certain times, and the original design and architecture have been unable to meet scalability requirements. In this case, opBNB emerged as the times require, providing new possibilities to solve the scalability problem of BSC.
 The implementation principle of opBNB
opBNB is a two-layer extension solution built on BSC. It is also compatible with EVM and is implemented based on the Bedrock version of OP Stack. Bedrock is the first official version of OP Stack. It contains a set of free, open source modular components, which allows the settlement layer to be replaced by chains such as BSC, thus creating opBNB.
Similar to the working principle of Bedrock, opBNB processes transactions off-chain and then publishes transaction data on the chain. In this way, on-chain data compression is achieved, thereby improving scalability. Specifically, users interact with the opBNB network through applications or directly through contracts on opBNB; Sequencers aggregate transactions, calculate state transitions and submit them to the rollup contract on BSC; Provers generate cryptographic proofs, Prove the validity of these state transitions; verifiers check the proofs to verify the correctness of the opBNB state.
Unlike Optimism and Coinbase’s second-layer solution Base, opBNB is built on BSC (not Ethereum). The performance of BSC itself is better than that of Ethereum. Therefore, the performance of opBNB is not only better than BSC, but also better than Optimism and other expansions. plan.
According to the official description, opBNB’s block time is 1 second, the gas fee for transfers is as low as $0.005, and the number of transactions per second (TPS) it can handle exceeds 4,000. Its performance is better than existing expansion solutions.
 Key features after capacity expansion and upgrade
Compared with BSC and the expansion plan on Ethereum, opBNB will have some key features to greatly reduce user costs, retain the security of BSC, and become one of the smart contract platforms with the best performance and scalability.
opBNB is still EVM compatible, which allows dApps and smart contracts on other EVM-compatible chains such as Ethereum, BSC, Polygon, etc. to be seamlessly migrated to opBNB without any code changes. This not only reduces developers' development costs, but also greatly improves application portability.
opBNB can inherit the security of BSC. It ensures the security of state transitions and transactions through sequencers, provers and verifiers, and rollup is protected through the settlement chain, which is BSC. BSC is one of the most secure public chains. High TVL is also one of the indicators that users are willing to believe in the security of the public chain. opBNB will be able to inherit the security of BSC.
Compared with the original OP Stack, opBNB will be more flexible and can add some customized functions. Although opBNB is implemented based on OP Stack, it does not mean that it is the same as other solutions that also use OP Stack. OP Stack provides a modular and replaceable design, so that more flexible updates can be achieved according to opBNB's own needs and the BSC ecosystem, such as changing the key parameters of opBNB and increasing the interaction with the blockchain. , change the data availability layer, etc.
opBNB is built on BSC and transaction costs will be lower. The three main costs of processing transactions on the blockchain include: execution costs, storage costs, and data availability costs. Rollup can move part of the cost from the first floor to the second floor, thereby reducing the overall cost. However, the calldata cost of publishing data to the first layer is still much higher than the computing and storage costs of the second layer. On the one hand, the main network corresponding to opBNB is BSC, which is cheaper than the corresponding Ethereum such as Optimism; on the other hand, opBNB can also use BNB Greenfield as the storage layer to further reduce costs. Therefore, opBNB’s transfer cost can be as low as $0.005.
opBNB is also one of the smart contract platforms with the best performance and scalability. In the blockchain system, Gas is used to measure the computing resources required to execute transactions. For blockchain, the gas limit of each block is fixed, which means that the total amount of transactions and calculations that each block can process is limited. opBNB uses both a shorter block time (1 second) and a higher block gas limit (100 million Gas) than other solutions, so it can achieve a capacity of 100 million Gas per second and TPS of more than 4,000.
 opBNB shows new possibilities
Relying on the existing strong products and communities of the BNB ecosystem, combined with opBNB’s low cost and high scalability features, opBNB may show new possibilities in the competition between Layer 1 and Layer 2.
 1. Binance’s user base
Binance is the largest cryptocurrency exchange, has the most users, and hosts a large amount of user funds. Binance’s users have a need to access decentralized products, applications and tools. Under regulatory pressure, Binance also has the need to build decentralized products. Binance’s huge user base is expected to provide a rich foundation for the development of opBNB, attracting more developers and users to use opBNB, and projects in the opBNB ecosystem may also receive more support from Binance.
 2. The ecological foundation of BSC
Since its launch, BSC has developed a complete decentralized ecosystem. BSC’s TVL has long been among the top three among all Layer 1 and Layer 2. As of June 21, it has recently had approximately 1.3 million daily active addresses and a daily transaction volume of approximately 3.8 million. Because opBNB is also compatible with EVM, applications, funds and users on EVM-compatible chains such as BSC can be easily migrated to opBNB. This is much easier than educating users on new public chains from registering wallets.
According to Messari’s summary report for the first quarter of this year, BSC’s TVL (including borrowings in the lending agreement, excluding the pledge amount of the liquidity pledge agreement) on March 31 was US$5.7 billion, ranking second among all public chains. Compared with the previous quarter, it increased by 10.2%.
 3. Application of BNB greenfield in opBNB
The second-layer solution needs to ensure that transaction data can be accessed and verified by anyone, which is also an important part of transaction costs. opBNB separates the data availability (DA) layer and execution layer to solve data access issues, allowing a variety of DA options to be selected. In the future, opBNB may use BNB Greenfield, the storage infrastructure in the BNB ecosystem, as the DA layer, which can not only increase BNB usage scenarios, promote the development of the BNB ecosystem, but also further reduce costs.
 4. Convenient cross-chain channel
Although Layer 2 such as Arbitrum and Optimism can also provide a low-cost interactive environment, except for stable coins and a few native tokens supported by exchanges, deposits and redemptions of other assets still need to be carried out through the Ethereum main network, which is unavoidable High gas fees. opBNB in ​​the BNB ecosystem has a unique advantage in this regard. In a centralized environment, Binance is very likely to support the withdrawal of major stablecoins from exchanges to opBNB; in a decentralized environment, through opBNB’s official Gas fees for deposits and redemptions across cross-chain bridges are also relatively cheap, and BSC is also one of the major cross-chain hubs. Most cross-chain bridges support BSC's cross-chain, and may also support opBNB in ​​the future.
 5. Support new application scenarios to meet the large-scale application needs of Web3
Compared with existing expansion solutions, opBNB has significantly increased the ability to process transactions quickly, efficiently and at low cost, and can meet the needs of large-scale Web3 applications in games, social networks, metaverse, high-frequency trading and other scenarios. For example, the blockchain game Crypto Blades, which once had more than 300,000 daily active users and nearly 8 million transactions per day, would make BSC congested, but it can run normally on opBNB.
 summary
The combination of BSC and OP Stack makes opBNB show strong competitiveness in terms of cost, performance, scalability and other aspects. Its implementation principle and modular design also allow it to have broad room for upgrades in the future, such as increasing the use of BNB greenfield.
The existing users of Binance and BSC and the potential support for opBNB are also conducive to the cold start of opBNB. The low-cost, high-performance opBNB may meet the large-scale application needs of Web3 in games, metaverse and other scenarios in the future.