BNB Smart Chain has activated the Pasteur hard fork, introducing upgrades aimed at strengthening cross-chain security, tightening validator controls and improving block-processing efficiency.
The upgrade went live on mainnet at 02:30 UTC on Aug. 25, while BSC continued operating with its existing 450-millisecond block interval. No major disruption was reported immediately following activation.
Pasteur brings together BEP-682, BEP-695 and BEP-675 under the broader BEP-673 upgrade framework. The changes had previously been tested on BSC’s Chapel testnet.
Stronger protection for cross-chain bridges
One of the key changes, BEP-682, improves how BNB Smart Chain verifies light blocks used in cross-chain infrastructure.
Previously, validator lists submitted during verification could contain duplicate entries. This created a potential risk because the same validator could theoretically be counted multiple times when determining whether a block had enough support.
Under Pasteur, duplicate validators are rejected before the network calculates the required approval threshold. As a result, every counted approval must come from a separate validator.
BNB Chain has not indicated that the issue was previously exploited or linked it to any known asset losses. The update is designed as a preventive security measure.
Validator key changes receive tighter controls
BEP-695 introduces additional safeguards around validator key rotation, penalties and governance participation.
When a validator changes its operator key, the previous key will no longer retain management authority. Pending penalties also remain attached to the validator, preventing operators from potentially avoiding sanctions simply by switching keys.
The upgrade also strengthens governance restrictions. Previously restricted addresses could potentially sign governance votes and have another account submit those signatures. The updated system checks the original signer before accepting a delegated vote, preventing restricted accounts from bypassing governance controls.
New block-processing method could increase throughput
The third major component, BEP-675, introduces an optional block-submission mechanism for specialized builders.
Under the traditional process, both block builders and validators execute transactions before a validator signs the proposed block. That repeated execution can consume valuable time within BSC’s short block interval.
The new approach allows builders to submit blocks that have already been executed. Validators can first verify the proposed block against consensus requirements, sign and distribute it, and then complete full execution checks.
Builders can continue using the existing process, while the new method must be activated through the network’s RPC interface.
Testing showed a potential 88% throughput increase
BNB Chain’s internal testing suggested that the new block route could substantially increase transaction throughput.
On QANet, an environment designed to simulate geographically distributed validators, throughput increased from 1,237 transactions per second to 2,324 TPS.
Average gas consumption per block also increased from approximately 46.35 million to 84.15 million, while the network’s 100-million gas limit remained unchanged.
BNB Chain has emphasized that these figures came from controlled testing rather than live mainnet conditions.
Mainnet adoption will determine the real impact
Pasteur does not raise BSC’s block gas limit or alter its 450-millisecond block production interval. Any improvement in practical capacity will therefore depend heavily on whether builders and validators adopt the new BEP-675 workflow.
Node operators were required to upgrade to client version 1.7.7 before the hard fork and remove the deprecated EnableBAL configuration field. Nodes running incompatible software risked losing synchronization with the mainnet.
The most important data now will come from real-world operation. Block utilization, transaction throughput, missed blocks and validator performance will determine whether the gains observed in testing translate into sustained improvements on BNB Smart Chain.
Pasteur therefore represents more than a routine protocol upgrade: it combines stronger bridge verification, tighter validator governance and a new path toward higher transaction capacity, while leaving actual performance gains to be demonstrated on mainnet.
