BSC Implements Pasteur Upgrade to Enhance Cross-Chain Bridge Protection
The Pasteur hard fork goes live on BNB Smart Chain, addressing security vulnerabilities in bridges and validators while pushing for enhanced transaction throughput.
The Pasteur hard fork went live on BNB Smart Chain (BSC) this Tuesday, addressing critical vulnerabilities in bridge verification processes and validator authorization mechanisms while rolling out a fresh pathway designed to accommodate increased transaction volume within individual blocks.
Through a Tuesday announcement, BNB Chain validated that the Pasteur upgrade had been successfully deployed to the BSC mainnet. According to the development team, this enhancement fortifies security measures across the network's bridge infrastructure, staking mechanisms and governance protocols, simultaneously enabling blocks to handle greater capacity without modifying the existing 450-millisecond block generation interval.
The enhancement incorporates three distinct BNB Evolution Proposals into a single deployment. BEP-682 eliminates the possibility of duplicate validator entries throughout cross-chain light-block verification processes, whereas BEP-695 implements stricter oversight regarding validator key rotation procedures, slashing mechanisms and governance voting participation. Additionally, BEP-675 modifies the methodology through which specialist builders present blocks to validators for approval.
This comprehensive upgrade ensures validators cannot be tallied multiple times when approving bridge transactions, strips authorization from outdated validator keys and prevents restricted addresses from participating in voting activities, all while striving to maximize transaction inclusion in blocks during periods of high network activity.
Pasteur targets fuller blocks
Within BSC's former block-building methodology, a builder would execute transactions prior to submitting a proposed block, after which the validator would perform execution again before providing a signature. According to BNB Chain, this duplicated effort consumed valuable time that builders needed within the network's 450-millisecond block generation window, occasionally resulting in blocks that were not filled to capacity.
Through BEP-675, builders gain the ability to submit blocks that have undergone execution on their end. Validators then verify the submitted block against established consensus rules, append their signature and broadcast it across the network, subsequently completing comprehensive execution verification. Builders retain the option to utilize the previous methodology, wherein validators perform transaction execution prior to signing.
During testing phases conducted on QANet, an internal testing environment engineered to replicate BSC's geographically dispersed validator configuration, this innovative route delivered approximately 88% increased throughput, escalating from 1,237 transactions per second to 2,324 transactions per second. The average gas consumption per block climbed from 46.35 million to 84.15 million units while both the block interval duration and the 100-million gas limit ceiling remained constant.
BNB Chain emphasized that these performance metrics originated from a controlled testing workload environment and should not be interpreted as actual mainnet performance measurements.
The Pasteur upgrade builds upon earlier enhancements that prioritized block time reduction. The Maxwell hard fork implementation on BSC decreased the average block generation time from 1.5 seconds down to approximately 0.8 seconds in June 2025, whereas BNB Chain reported that the following Fermi upgrade successfully reduced it further to 450 milliseconds.