SKN | BNB Chain Activates Pasteur Hard Fork to Strengthen Bridge Security and Boost Throughput

Key Points

• BNB Smart Chain activated the Pasteur hard fork, introducing changes targeting bridge verification, validator authorization and governance security.
• A new block-building mechanism increased throughput by about 88% in controlled QANet testing, from 1,237 to 2,324 transactions per second.
• The upgrade maintains BSC’s 450-millisecond block interval while seeking to use available block capacity more efficiently during periods of heavy demand.

BNB Smart Chain (BSC) activated its Pasteur hard fork on Tuesday, combining security changes with a new block-building mechanism designed to increase transaction capacity without shortening the network’s existing 450-millisecond block interval. The upgrade addresses vulnerabilities and inefficiencies across bridge verification, validator authorization and block production as BSC seeks to improve performance without altering its current block cadence.

The upgrade incorporates three BNB Evolution Proposals: BEP-682, BEP-695 and BEP-675. Together, they change how validators are verified in cross-chain operations, strengthen controls around validator keys and governance, and introduce a more efficient route for submitting already executed blocks.

Bridge and Validator Security Tightened

BEP-682 addresses duplicate validator entries during cross-chain light-block verification. The change is designed to prevent a validator from being counted more than once when bridge approvals are processed, strengthening the verification process used for cross-chain activity.

BEP-695 focuses on validator authorization, including key rotation, slashing and governance voting. The upgrade removes authority from outdated validator keys and blocks restricted addresses from participating in voting.

These changes target infrastructure that sits beyond ordinary transaction processing. Bridge security has become an important concern across blockchain networks because vulnerabilities in cross-chain verification mechanisms can create significant risks for assets moving between networks.

Pasteur therefore combines performance improvements with measures intended to reduce the possibility of unauthorized validator influence.

Pasteur Targets Fuller Blocks

The largest performance change comes through BEP-675, which modifies how specialist builders submit blocks to validators.

Previously, a builder executed transactions before submitting a proposed block, after which the validator executed those transactions again before signing and broadcasting the block. BNB Chain said this duplicated work consumed time within BSC’s 450-millisecond block window and could leave blocks underfilled.

Under the new mechanism, builders can submit blocks they have already executed. Validators verify the proposal against consensus rules before signing and broadcasting it, while completing full execution verification afterward.

Builders can still use the previous process, providing flexibility during the transition.

Controlled Tests Show 88% Throughput Increase

BNB Chain tested the new block-building route on QANet, an internal environment designed to replicate the geographically distributed nature of BSC’s validators.

The test produced a substantial increase in throughput. Transactions per second rose from 1,237 to 2,324, representing an increase of approximately 88%.

Average gas used per block also increased from 46.35 million to 84.15 million, while the block interval remained unchanged.

The results suggest that the upgrade could allow BSC to utilize more of its existing block capacity rather than relying solely on faster block production.

BNB Chain cautioned, however, that the figures came from a controlled workload and should not be interpreted as direct measurements of mainnet performance.

BSC Continues Its Push for Lower Latency

Pasteur follows a series of BNB Chain upgrades focused on transaction processing speed.

The Maxwell hard fork in June 2025 reduced BSC’s average block time from approximately 1.5 seconds to around 0.8 seconds. The subsequent Fermi upgrade brought the interval down to approximately 450 milliseconds.

Pasteur takes a different approach by preserving that 450-millisecond interval while attempting to increase the amount of useful transaction processing completed within each block.

That distinction could become increasingly important as blockchain networks compete not only on raw transaction speed but also on how efficiently validators and block builders use available computational resources.

Security and Capacity Remain Linked

The Pasteur upgrade illustrates BSC’s effort to address two pressures simultaneously: maintaining stronger controls over critical network infrastructure and increasing capacity without continually reducing block times.

For users, the immediate impact will depend on how the changes perform under real mainnet workloads. The controlled testing results provide an indication of potential gains, but actual throughput will vary according to transaction composition, network demand and validator behavior.

The broader test for BNB Chain will be whether the new architecture can deliver fuller blocks while maintaining reliable validation and stronger bridge and governance protections. If those objectives hold under sustained mainnet activity, Pasteur could give BSC additional capacity without requiring another reduction in its already short block interval.