Meet With BNB Chain Experts #2: Scale BNB Chain Into Next Level with zkRollup

Hey there BNB Fam!

Welcome to our all new Podcast series: Meet With BNB Chain Experts. For each episode we will invite experts in the BNB Chain ecosystem to discuss topics that will help projects and builders learn more about ‘how to build great Web3 Dapps’.

After discussing with ecosystem projects on soulbound tokens during our first episode, this time we touched on the topic of zkBNB - which reiterates our unwavering commitment to provide the most advanced and secure blockchain infrastructure for Web3 dApps.

We invited Jimmy from NodeReal, a one-stop blockchain infrastructure and services, along with Alvin and Arno, two intrinsic members of the BNB Chain team, to have an in-depth discussion on this exciting and promising technology.

Participants

Alvin Kan, Director of Business Operations, BNB Chain

Arno, Solution Architect, BNB Chain

Jimmy, Technology Solutions Director, NodeReal

Here is a summary of the 2nd episode. If you want to listen to the full content please click here.

1) Why zkRollup is needed in blockchain?

Web3 is still in a very early stage from the active user perspective. On the BNB Chain there are around 4 million addresses, compared with 2000 million global users of Facebook. If  we want to make Web 3  more accessible to common users the scalability problem must be solved. zkRollup as a L2 scalability solution is more flexible and has more chances to expand very quickly compared with L1 solution.

2) zkBNB is expected to reach 5-10k TPS in the future

Currently our testing is around 700 TPS. This is something we can expect to increase. We’re doing the optimization work for the proof algorithm.In the future we can consider hardware optimization as well to increase the efficiency of the algorithm. Our aim is to achieve between 5K and 10K TPS on our zkBNB.

3) zkBNB’s unique features

There is a built-in instant AMA swap and also built-in NFT marketplace, which is kind of our unique feature. We want to build the native solution for the NFT management marketplace, increase our usage as well as to provide the best experiences for the developers.

We also have a feature named “full exit” - you can request to withdraw all the funds if you don't trust it anymore, or for any kind of the reasons. I don't think I've seen this on any other chains before.

4) zkBNB has good user experience

We leverage very innovative technology to make the user experience even better. First in zkBNB we use wallet management technology that is compatible with the commonly-used wallets. We’re going to support the ECDSA signatures and EIP-7112, therefore most of the ethereum wallets can seamlessly support us. And we are ready for mass adoption. We are using the sparse Merkle Tree storage which is a persistent storage, while other rollup solutions just put the state tree in memory to make the data consistent.

5) Liquidity in zkBNB

It depends on the users in the community. We can call on our community to move the liquidity there because it’s more decentralized. But we cannot really make users do that. We just hope that it can work since it’s going to lower the transaction fees so if a decentralized exchange wants to be successful and attract more users they would want to use such a solution. AMM in zkBNB is very similar to the Uniswap version 2. Anyone can become a liquidity provider by just depositing equivalent value of each underlying token to the liquidity pool.

6) zkBNB is still decentralized

For zkBNB we don't have to worry about centralisation because it is just like the transaction execution engine: generating the snark proof and sending the data to L1. That's quite a different concept compared with the sidechain. We have multiple validators running the chain in the sidechain solution but there is no such concept in zkBNB: all the transactions are verified on the main chain. Besides, zkBNB code has been open-sourced so any developer can just go to our GitHub Repository and set up by themselves.

7) Decision metrics for projects moving to zkBNB

It’s always good to try and master new technology as soon as they are out because you never know how big your project can be. It will be too late if it begins to grow exponentially and then you get stuck down at this specific time. So the earlier you adopt the better. Another consideration is that if you want to use the natively embedded NFT marketplace or AMM exchange, the feature is already available and will reduce your workload. Last but not least, security is one of the key reasons why people would build on ZK.

We’re working with the GameFi partners together to make the zkBNB very suitable for the GameFi industry. And also lifestyle. I think it’s going to be a nice trend of footable loyalty tokens, or reward mechanisms leveraging our solution. It can have both a high throughput and lower transaction costs that potentially some projects might wanna look into.

8) Besides TPS, how fast can the finality go?

Currently it's around 5 minutes because the prover needs time to do the proof generation. If we want to make it faster, we can simplify the algorithm itself and use the optimization technique to reduce it even further. So there should be no limit to how fast we can. We want to make it in seconds. Even in milliseconds. This is something we want to do in the future.

9) The differences between BNB Application Sidechain and zkBNB

First, the sidechain is just like a chain running in parallel with the BNB Smart Chain. From BNB Smart Chain to the side chain we require a bridging solution to allow users transfer assets back and forth.  For zkBNB you can just lock your assets on the main chain and create your assets on zkBNB when you deposit your assets. And when you withdraw assets, the system will burn your assets on zkBNB and unlock your assets on the main chain. So this is something you can communicate with L1 and L2. We don’t need a bridging solution.

Second, BNB Application Sidechain is fully EVM-compatible. We can do a lot of customizations or optimizations for different users.We can create some special transactions with higher priority, , change the token economy design, or change the blocking reward mechanism, etc to meet different special requirements of different customers. But for zkRollup at this moment it is not possible. This is something we want to add in the future.

ZK rollup is maybe one of the best solutions for the scalability problem. If you want to move to zkBNB, feel free to contact our Growth Ops team. We’re more than happy to share our experiences and best practices and bring you to an exciting journey.

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