BNB Chain Tech Roadmap 2023 - Binance Chain

Key Takeaways

As the most actively used L1 blockchains (~1M DAU), BNB Chain focuses on the mass adoption infra.
Scalability will be the long term target. BNB Chain will work with the Ethereum community together to build the best performant EVM compatible client for BSC, and it will also leverage emerging technologies, such as ZKP and Optimistic Rollups and modular blockchains, to provide cheaper, scalable and secure solutions for decentralized applications that targets millions of users.
BNB Chain will take a more pragmatic approach and introduce a new Storage network – BNB Greenfield to solve data ownership and empower a data economy, such as personal data market, user generated content (UGC) exchange, and digital publishing, etc.
BNB Chain will continue to improve user experience, including introducing better cross-chain solutions, strengthening security via AvengerDAO 2.0, and building smart wallets via MPC and Account Abstract with community partners.
BNB Chain will not stop further decentralization, expanding validators from 40 to 100 (slowly but surely.)

Theme	2022 So far	Goals starting from 2023
Scalability	BSC Block gas limits 140M (2.2K TPS)Parallel EVM 2.0 Fast Node and increased the syncing efficiency by ~30%Erigon client	BSC Block gas limits to 300M (5K TPS)Rust based BSC Node ClientParallel EVM 3.0State-offload to reduce data footprint
Decentralized Data Economy		BNB Greenfield
Multi-chain Solutions	BNB SideChain*ZkBNB (testnet)	Multiple ZKP rollup based L2 (not zkEVM) for applications with massive users and pre-defined logic.Multiple optimistic rollup based L2 (EVM equivalence) for applications that want to build their own tokenomics and open platform for their own ecosystems.Support EIP 4844
Security	AvengerDAO 1.0	AvengerDAO 2.0Cross Chain Security
Non-stop Further Decentralization	Open sourced BNB Beacon chain. Optimized the block mining logic in 1.1.18 (fair mining)BEP131: Introduced Candidate Validators Onto BNB Smart Chain, and already Expanded BSC validators from 21 to 26BEP-127 Temporary Maintenance Mode for Validators to improve the network stabilityBEP153: Native Staking	New Validator Reward model (balanced mining)Validiator reputation systemsIntroduce Incentive Model for Beacon Chain validatorsExpand BSC/BC total validator to 150, active validators from 29(BSC) + 11(BC) to 100
BNB Mass Adoption Infra	Wallet Servicesdecentralized StorageOraclesDAO ToolingData IndexingRPC Services	Account Abstraction (Social Login, Gasless)Identity SolutionHybrid ApplicationCommunication layerGaming Infra

*BNB Sidechain: Only for Hybrid Solution and Build your own ecosystem. Only suitable for big names people may trust, e.g., game studios, financial service companies or Web2 giants.

Scalability

Performance is an important factor to consider when it comes to blockchain technology. Because blockchain is a decentralized system that relies on a network of nodes to process and validate transactions, the speed at which transactions are processed can have a significant impact on the overall efficiency and effectiveness of the system. One of the main limitations of blockchain technology is its performance, or the ability to process transactions reliably and quickly.

Increased Block Gas Limit

One factor that can limit the performance of blockchain technology is the block size, for EVM compatible blockchains. We express the block size as Block Gas Limit.

Gas is the EVM network’s measurement of the computing effort needed to carry out a transaction. In a network with a high gas limit per block, each block can carry more transactions. We started 2022 with an 80M gas limit and gradually increased to 140M – approximately 4.6 times higher than the Ethereum network, the largest among all EVM compatible networks. Such a high gas limit enables BNB Smart Chain to handle over 2K transfer transactions per second (TPS).

A high gas limit poses a bigger challenge to the efficiency of block processing and to storage. This is why the BNB Chain Community implemented Parallel EVM, which boosts performance by allowing transactions to be executed simultaneously, and worked actively on providing Fast Node implementation to separate processing and state verification.

In 2023 we plan further increase in block gas limit towards 300M. This will allow BNB Chain to support up to 5K transactions per second (TPS) and solidify the already leading performance position among public L1s.

Parallel EVM

In its origin, the EVM was designed to be single-threaded, meaning that it can only execute one instruction at a time.

Parallel EVM is an extension to the EVM that allows it to execute multiple instructions in parallel, which improves the performance of the network. However, implementing parallel execution in the EVM is challenging. Starting in May 2022, the NodeReal and BNB Chain core teams designed and deployed several iterations to the BSC mainnet and are continuously looking for even more improvements to the parallel engine in 2023.

For more information regarding on parallel EVM contributed by NodeReal:

With Parallel EVM versions 1 and 2, we’ve focused on the foundation, architecture, and to set up the workflows. In 2023, Parallel EVM 3.0 will apply parallel to validator mode. The current implementation is very complicated. Rather than adding more code, it would be better to take a break and rethink it.

BSC Client

BSC client requires a specific hardware configuration to maintain a chain node and participate in network security, especially on the storage part. This can make the BSC client heavy on hardware resources.

Fast Node

One way to reduce the hardware requirements of a BSC node is to use more efficient protocols by separating processing and state verification. Separating the processing and verification of transactions helps improve client performance and scalability. Two types of nodes make full use of different storage: one is called fast node and the other is called verify node. The fast node will do block processing with a flattened key-value database and all verification against blocks except the state root. The verify node receives diffhash from the fast node and then responds to the Merkle Patricia Trie (MPT) root to assist with the state root verification.

The fast node can slow down the storage growth by 60% to ~90%, according to different settings, and increase syncing efficiency by about 30%. Also, in case 100% state consistency is not needed, the newly introduced none mode can assist in such a scenario.

If you want to learn more about this feature, please refer to the docs.

Erigon Client

While the Fast Node allows users to trade consistency versus performance for the cases where eventual consistency is sufficient, Erigon client provides an improved performance and sync speed for full-featured nodes.

During 2022 we’ve added support for Erigon clients. Erigon is based on Geth and the team made some fundamental changes to the full sync algorithm and the storage system, allowing you to sync an BSC archive node much faster and using less disk space.

Erigon pioneered “Staged Sync” architecture, as well as introduced MDBX as the database of choice. When Geth synchronizes a full node, it downloads the blocks’ data. Then, it replays the transactions while working on other operations, for instance, retrieving the senders of the transactions from the private signatures or verifying the block headers. As a result, the process is less efficient since many things are happening simultaneously. Erigon instead breaks down the process into different stages and completes them in sequence; this means that the program will first complete a stage before moving on to the next, making the overall process faster.

In 2023, We aim to provide improved performance across every vertical, including CPU, RAM and disk space. We also plan to provide configurable profiles allowing users to explore the tradeoffs between different modes, depending on the usage profile.

Fast Finality

Currently, on the BNB Smart Chain, all full nodes and validators need to wait until enough blocks have been produced to ensure a probabilistic finality. According to the whitepaper, with 44 validators full nodes and validators can wait 1/2*21+1=11 blocks (33seconds) to ensure a relatively secure finality. This can be considered quite a long time for some critical applications, especially for cross-chain in our multi-chain strategy. This time will increase even more as the chain grows and more and more validators join.

In 2023, the Fast Finality feature will be a paramount milestone for blockchain security. Once the block is finalized, it would not be reverted anymore. The fast finality feature is very useful. Users can make sure they get accurate information from the latest finalized block, then decide what to do next, instantly. This reduces the time for bridges to wait to confirm cross-chain packages.

Scalability Through Multi-chain Strategy

In 2022, BNB Smart Chain (BSC) was able to handle 2.2K TPS (theoretically) and will be increasing its capacity to 5K TPS in 2023. BSC is the most active chain with the largest daily active users (~1M DAU even in the 2022 bear market) and most active DEX as well.

BNB Smart Chain will position as Hubs and Settlement layers of the BNB Chain multi-chain architectures. DeFi projects with low/medium transactions volumes may still prefer to stay in BNB Smart Chain to enjoy the comprehensive DeFi Lego and much better liquidity. At the same time, BNB Smart Chain will become a critical Hub of all of these different L2s for their security and settlements as well.

BSC does have some challenges on higher gas fees. Games and other dApps with large daily active users usually introduce gasless solutions and implement a lot of computation intensive on-chain logics (tx with very high gas fees) – they are looking for a cheaper scalable platform with the same security as BSC and keep enjoying the largest liquidity of BSC as well.

In 2022, BNB Chain introduced BNB Sidechain. However, there are some limitations: the Sidechain solution is not secure yet and only suitable for big names people may trust with solid infra partners, like FNCY Chain with NodeReal.

In 2023, BNBChain will embrace more diverse scalable solutions pragmatically through ZkBNB (Mainnet 2023 H1) and new Optimistic Rollup (mainnet 2023 H1), which will provide more options for different business cases.

A high level comparison and business case requirements are listed as initial thoughts in the below table.

Metrics	BSC	ZkBNB	Optimistic Rollup	BNB SideChain
Mainnet	Ready	H1, 2023	H1, 2023	Ready
Gas Token	BNB	BNB	BNB	App Specific Token
VM	EVM	Application specific logics	EVM	EVM
TPS*	2.2K (Target 5K in 2023)	5K in 2022	5-10K	>5K
Gas Fee/Gasless	~$0.3Expensive	Cheaper	Cheaper	A lot cheaper based on the application’s own decision.
Withdraw/Finality	33 seconds (6 secs after fast finality)	2-3 Minutes	<7 days	3 seconds
Security	Secure	Secure/Elegant Exit	Secure/Elegant Exit	Decided by Network operator
Validators	50 (21 cabinet, 8 candidates, and 21 inactive)	1	TBD	Usually Permissioned/Consortium blockchain
Recommendation	DeFi Hub and LegodApp with <1M DAU	More suitable for NFT and Token transactions, e.g., Gaming, and high frequent derivatives (DyDx or LoopRing). More suitable for applications with massive users but focused and dedicated functions that can be translated to efficient ZKP circuits. Great chain for Web2 devs since they only have to use SDKs. zkBNB is very suitable for games that want smooth user experience and that do not require smart contracts to be deployed in their ecosystem.	More suitable for Applications that want to be an open platform & ecosystem but still enjoy the similar security level as L1 and an easy way to exit running. Game studios & engines might prefer Optimistic rollup over zkBNB because it allows them to create an ecosystem of developers, smart contracts and project to build on top of their chain. This is not the case with zkBNB.	Only for Hybrid SolutionBuild your own ecosystem, target customers: Web2 game studio or financial service companies. However, App Sidechain solution is not secure yet and only suitable for big names people may trust.

*TPS will be calculated based on the “Token Transfer” Transaction (not complex one, e.g., AMM).

BNB SideChain

In 2022, BNB Sidechain introduced a modular framework for the PoSA side chain, which was contributed by Ankr and NodeReal. The purpose of BNB Sidechain is to enable large scale companies to build their own ecosystem. It comes with full Ethereum compatibility (EVM) and operates on the PoSA consensus. It is very suitable for the permissioned and consortium blockchain. There have been some pilots in the community in 2022, such as Ankr’s MetaApes, and FNCY Chain – supported by NodeReal. However, the App Sidechain solution is not secure yet and lacks enough liquidity. It is a common issue in all L1s with sidechain solutions, including Avalanche subnets, Polygon supernets, etc. Sidechain solutions have not been strongly adopted by communities, so far.

Based on existing successes, such as FNCY Chain or ApeCoin Chain, Sidechain will be more suitable for big names or brands that people may trust that have strong network operation experience with partners.

zkBNB

The BNB ZkRollup (zkBNB) is built on ZK Rollup architecture. ZkBNB bundles (or “rolls-up”) hundreds of transactions off-chain and generates a cryptographic proof. These proofs can come in the form of SNARKs (succinct non-interactive argument of knowledge), which can prove the validity of every single transaction in the Rollup Block. ZkBNB started its development based on Zecrey’s initial version. With contributions from Zecrey, Nodereal and BNB Chain Core team, zkBNB currently is in the testnet phase, and is targeting mainnet in Q1 2023.

The short term objective of zkBNB is not to try to build an EVM compatible zk rollup. Instead zkBNB will focus on building dedicated functions, such as NFTs and Token Transactions, that can be translated to efficient ZKP circuits that will be more suitable for gaming in ImmutableX or high frequency derivatives (like DyDx or LoopRing). zk-EVM will be the future of ZK Rollup. However, current algorithms and implementations need a little bit of time to optimize performance to really meet high performance expectations here (i.e., target 100K TPS).

opBNB

Before the readiness of zkEVM, Optimistic Rollup is a more realistic and secure solution to provide a purely EVM-equivalent scalable solution. In 2022, Optimism and Arbitrum demonstrated strong adoption in the Ethereum ecosystem.

At the same time, EIP-4844 (Proto-danksharding) will introduce a new transaction type: blob-carrying transaction.

A binary large object (blob) is a big piece of data that is cheaper to publish and store on-chain than calldata. By using blob-carrying transactions, rollups can upload all their data to Ethereum. After implementing EIP-4844, we could see a 10-100x decrease in transaction fees in both optimistic and ZK-rollups, which will make the optimistic rollup >20K TPS (in theory).

In 2023, BNBChain should expect to see more Optimistic rollup solutions. Game studios and engines might prefer Optimistic rollup over zkBNB because it allows them to create an ecosystem of developers, smart contracts and projects to build on top of their chain, which still enjoy the similar security level as BNBChain. While BSC may support EIP-4844 as well, BNB Greenfield also provides another candidate for the data availability solution.

BNB Storage – BNB Greenfield

The crypto industry has already picked up financial assets: tokens, stablecoins, and DeFi cover many economic scenarios. On the other hand, NFTs implement arts and collectibles. But there are plenty of items that are not innovated well enough. One such area is data.

The value of a data asset is not self-evident when it is just held by one person. Data becomes much more valuable when it is shared and used. However in the current economy it’s locked by centralized storage and social platforms.

We foresee the need to create a new Web3 infrastructure for data. So, we’ve decided to create a new BNB Chain side blockchain and relevant infrastructure to enable permissioned data sharing and monetization, spurring various business use cases and enriching the blockchain ecosystem. With this new infrastructure, users can “login”, create, own, and trade their data assets at another level of freedom, and what is more, embrace another level of transparency on how their data is owned and used.

Our plan is for BNB Storage to be an economically self-sustained, service-oriented ecosystem. The real power of the ecosystem will lie in that the platform is not only designed to store the data, but also to support the creation of value based on the data assets and its related economy.

You can get more details from this whitepaper.

BNB Chain Security

AvengerDAO

AvengerDAO aims to protect users from financial losses and malicious contracts. To achieve this, the initiative has partnered with top global security providers and blockchain applications to deter malicious actors and raise awareness on safety and security in the ecosystem. AvengerDAO is a collaboration of Web3’s leading security firms and the early adopters of blockchain technology. Founding members include, Certik, Go Plus, SlowMist, Zokyo, BlockSec, Hashdit, Verichains, Pessimistic, CoinMarketCap, TrustWallet, PancakeSwap, BSCtrace(NodeReal), BSCscan, MathWallet, DappBay, Coin98, and Opera.

Three innovative services have been designed and “Meter” has already deployed to the BNB Chain mainnet.

Meter will allow applications to request security ratings on smart contracts, domains, and addresses, and will send back alerts when users interact with potentially malicious entities. Watch warns subscribers in real time when security exploits occur and Vault assists the safe passage of funds between parties.
Watch is an active API stream that sends out active alerts to subscribers when malicious contracts, domains, or entities are detected. External applications can join the API stream that consolidates active security issues,then alerts the subscribers.
Vault is a service that locks up funds for clearing according to the providers’ internal rules. When a transaction is triggered, it allows funds to be locked until certain pre-set conditions are met, such as a security scan being completed and verified or a prescribed time limit being reached.

In 2023, “Watch” and “Vault” will be implemented and we plan to improve the quality and quantity of AvengerDAO services to support increased interest from the community and rapid growth of usage.

Besides these three key security services, a comprehensive security and risk management framework will also be introduced in 2023 to standardize the software development life cycle (SDLC) process across blockchain projects, including best practices covering smart contract and infrastructure development, deployment procedures, privilege (private key) management, financial risk management, and incident response process, etc. All projects will have good references to implement these best practices on security and risk control, and it will improve their security and maturity to the next level.

Reducing the risk for the users, connecting projects, and overall ecosystem should be “Priority One” in BNB Chain.

Improved Cross Chain Security

Having secure cross-blockchain communication is of paramount importance because it ensures that information and assets can be securely transferred between different blockchain networks. This can help to prevent tampering, fraud, and other security breaches, which can damage the integrity and trustworthiness of the blockchain ecosystem.

In 2022, cross-chain between BNB Beacon Chain and BSC was exploited because of Zero Day vulnerabilities in the Cosmos SDK. The hotfixes (1.1.15 and 1.1.16) are implemented with almost zero direct impact on users and dApps.

In 2023 we plan to further tighten and improve BNB Chain cross-component security including migration to generic merkle proof specification (ICS23), introducing additional sequence verification, and improvement around relayer candidate management.

Progressive Decentralization

There were 21 active validators and several inactive validators on the BNB Smart Chain. The absence of rewards for idle validators weakened the incentive for node operators to maintain high-quality nodes and for BNB holders to delegate their tokens. Inactive validators are as vital as active nodes, as they are able to replace an active validator if one goes to jail.

In 2022, BNB Smart Chain introduced “candidate validators” in order to increase decentralization and enhance the network’s reliability and accessibility. This boosted resistance to censorship and increased the network’s resilience against outages or attacks. Even if more than 50% of the validator set is blocked or taken offline, the network can still function.

At the end of 2022, BNB Smart Chain had 29 active validators (21 cabinet validators plus 8 candidate validators) including top infra providers like Coinbase Cloud, Figment, InfStones, Ankr, HashKey, NodeReal, and more.

There are several ways in which a blockchain network can be decentralized, and the specific steps that a network can take to expand its decentralization will depend on its current design and the goals of its developers.

Here are some strategies that BNB Chain community will use to expand decentralization:

Increase the number of validator operators: One way to promote decentralization is to increase the number of nodes on the network. This is done by allowing more nodes to participate in the consensus mechanism. Increasing our active validators seats from 29 to 100 by the end of 2023 will bring more robustness for the BNB Chain network. The more nodes there are on the network, the more resilient it will be.
Introduce more consensus mechanisms: Another way to expand decentralization is to use multiple consensus mechanisms, rather than relying on a single algorithm. This can help to distribute power and influence more evenly across the network, making it less susceptible to control by any one group of users. For this reason Beacon Chain will open to validators to the community. Because Beacon Chain is the underlying chain where all voting and staking is happening, it is necessary to increase the decentralization within Beacon Chain.
Increase on-chain governance: Decentralized networks often use on-chain governance mechanisms, such as voting or on-chain decision-making, to allow validators to have a say in the direction and operation of the network. This can help to promote decentralization by giving validators a greater ability to influence the network and its rules.

BNB Beacon Chain is kept safe by a group of validators who are trusted and have already been approved. The current validator set controls how a validator gets in and out of a validator seat. Even though this system has a lot of bandwidth, its immutability is questioned because censorship and blacklisting are easy to do.

For this reason, BEP-159 is proposed. In 2023, anyone will be able to run for validator and have an equal chance of being elected. After 24 hours, the most staked nodes will be elected as a new set of validators. A new block will be generated by the validators chosen at the election. The community will decide the total seats of the validator set. It will encourage greater decentralization and community participation.

BNB Mass Adoption Infrastructure

BNB Chain kept its status as the number one active blockchain in 2022. One of the key drivers for this ranking is offering the right toolkits to developers for ease of development. BNB Chain is home to numerous gaming projects and all of these projects are working together to improve their infrastructure and UX. Some of the important categories like Oracles, Decentralized Storage, Blockchain Access Services and Data Indexing, Soul Bound Token, are dramatically improved.

In 2023 the BNB Chain community is committed to making sure public infrastructure is top-notch and provides foundational building blocks for large scale applications. Mass adoption Infra will be very important here including (but not limited to):

Web2 developer-friendly toolings:
Account abstraction (AA) and Wallet services would enable users to transact with greater privacy and security as there is no longer a need to directly connect wallets, social recovery of user wallets, micro-transaction, significantly reduce gas costs, batching of transactions etc.
Web3 Identity will become a key infrastructure part by supporting “almost” web2 native user experience for web3 dApps (through authentification services). That will help with scaling Web2 users onboarding to Web3, through allowing custom user settings including social recovery, supporting social interactions in Web2 way. Another use case is attestation of all kinds: physical (POAP), digital (verified credentials, KYC, and proof of personhood) that find their application in unlocking use cases across all verticals with gated/controlled access and regulatory compliance.
We want to enable a messaging/communication layer such that any user can tap into messaging service and request on-chain tech support. This could increase trust and boost confidence for end users to use dApps and conduct transactions.
Blockchain Data Indexing and Query:
Gaming infrastructure: To improve overall game development experience, top gaming studios and game engines may need to work together with BNB Chain core team to build easier SDKs and development tooling.
Hybrid applications are becoming super critical. These are the applications that are not entirely on-chain, taking advantage of both blockchains and other systems to improve their trust models. Hybrid applications could be supply-chain projects, governance voting, auditing, invoice forwarding, loyalty programs, medical records, educational records etc. The BNB Chain community is prioritizing infrastructure required for hybrid applications. To enable such applications on a public network, the basic requirement is data and access management.

We believe these upgrades and the development of new infrastructure can enable mass adoption of this technology.