BNB Smart Chain (BSC) has activated its Pasteur hard fork, introducing a series of changes aimed at strengthening bridge, validator and governance security while improving the network's transaction capacity.
BNB Chain confirmed the upgrade went live on the BSC mainnet on Aug. 25, combining three BNB Evolution Proposals (BEPs): BEP-682, BEP-695 and BEP-675.
According to BNB Chain, the upgrade is designed to improve cross-chain verification, validator key management and block-building efficiency without increasing BSC's current 450-millisecond block time.
Pasteur Hard Fork Strengthens BSC Security
The Pasteur upgrade introduces several changes targeting potential weaknesses in BSC's bridge and validator infrastructure.
BEP-682 changes cross-chain light-block verification by preventing duplicate validator entries from being counted more than once.
This is designed to make validator participation in bridge verification more robust and reduce the possibility of duplicate entries affecting approval calculations.
BEP-695 focuses on validator security and governance. The proposal tightens controls surrounding validator key rotation, slashing and governance voting.
Under the new rules, outdated validator keys lose their authority, while restricted addresses are prevented from participating in governance votes.
Together, these changes are intended to improve the security of BSC's validator and cross-chain infrastructure.
BEP-675 Targets Higher Transaction Throughput
The third component, BEP-675, changes how specialized block builders submit blocks to validators.
Previously, a builder would execute transactions before submitting a proposed block. The validator would then execute those transactions again before signing the block.
BNB Chain said this repeated execution could consume valuable time within BSC's 450-millisecond block window, potentially resulting in blocks that were not fully utilized.
Under BEP-675, builders can submit blocks that they have already executed.
Validators can then check the proposed block against consensus rules, sign and broadcast it, while completing full execution verification afterward.
Builders can still use the previous block-building method if required.
BNB Chain's official Pasteur hard fork announcement
BSC Test Shows 88% Throughput Increase
BNB Chain tested the new block-building mechanism on QANet, an internal environment designed to simulate BSC's geographically distributed validator network.
The test showed transaction throughput increasing from approximately 1,237 transactions per second to 2,324 TPS, representing an increase of about 88%.
Average gas used per block also increased from approximately 46.35 million to 84.15 million.
Importantly, the test maintained the same 100-million gas limit and block interval.
However, BNB Chain emphasized that these results came from a controlled test environment and should not be interpreted as actual mainnet performance.
Real-world throughput will depend on transaction types, network conditions, validator performance and block-builder behavior.
Pasteur Does Not Increase BSC's Block Speed
The latest hard fork is not designed to make BSC's block production faster.
Instead, BNB Chain is attempting to make better use of the existing 450-millisecond block window.
This distinction is important because BSC has already undergone several upgrades aimed at reducing block times.
The Maxwell hard fork reduced BSC's average block time from around 1.5 seconds to approximately 0.8 seconds in June 2025.
BNB Chain subsequently introduced the Fermi upgrade, which brought the block interval down to approximately 450 milliseconds.
Pasteur takes a different approach by improving how transactions are processed within that existing timeframe.
Why the Upgrade Matters for BNB Chain
Higher block utilization could become increasingly important as activity on BSC grows.
BNB Smart Chain hosts a large ecosystem of DeFi protocols, decentralized applications, stablecoins, games and token projects. Higher transaction capacity can help the network handle periods of increased demand without relying solely on shorter block times.
The security changes are equally significant.
Cross-chain bridges and validator infrastructure are critical components of blockchain networks. Weaknesses in validator authorization or bridge verification can potentially create risks that extend beyond a single application.
By preventing duplicate validator entries, removing authority from obsolete keys and restricting unauthorized governance participation, Pasteur aims to strengthen several layers of BSC's infrastructure.
BNB Chain official website
Three Key Changes in Pasteur
Upgrade | Main Focus | Expected Impact |
|---|
BEP-682 | Cross-chain verification | Prevents duplicate validator entries |
BEP-695 | Validator & governance security | Strengthens key rotation, slashing and voting controls |
BEP-675 | Block building | Improves block utilization and potential throughput |
The combination gives Pasteur a broader scope than a simple performance upgrade.
It addresses security, validator authorization, governance and transaction processing in a single BSC mainnet upgrade.
BNB Chain Continues Its Scaling Strategy
Pasteur follows a series of BNB Chain upgrades focused on improving BSC's performance.
The network has progressively reduced block times while working to increase transaction processing efficiency.
Rather than continuing to reduce the block interval, Pasteur focuses on optimizing the work performed during each block cycle.
If the improvements observed in controlled testing translate effectively to mainnet conditions, BSC could process significantly more transactions without requiring another reduction in its current block interval.
That could provide additional capacity for the network while maintaining its existing consensus timing.
What Comes Next for BSC?
The immediate focus will be on how Pasteur performs under real-world mainnet conditions.
The QANet results provide an indication of the potential benefits of BEP-675, but actual performance will depend on the workload and network environment.
Developers and validators will also need to monitor the security changes introduced through BEP-682 and BEP-695 as the updated rules operate on mainnet.
For BNB Chain users, the upgrade is primarily an infrastructure change rather than a new user-facing feature. Its effects should instead appear through improvements to network reliability, block utilization and security over time.
Final Thoughts
The Pasteur hard fork marks another significant infrastructure upgrade for BNB Smart Chain.
By combining BEP-682, BEP-695 and BEP-675, BNB Chain is addressing several areas at once: cross-chain security, validator authorization, governance protection and transaction processing.
The most notable performance result comes from controlled testing, where the new block-building route increased throughput by roughly 88% without changing BSC's 450-millisecond block interval or 100-million gas limit.
However, test results are not a guarantee of equivalent mainnet performance.
For the BSC ecosystem, the more important question now is whether Pasteur can deliver these efficiency gains under real network conditions while strengthening the security of bridges and validators.
If successful, the upgrade could give BNB Smart Chain additional room to handle growing DeFi, GameFi and dApp activity without relying solely on faster block production.
