BNB Chain Activates Pasteur Hard Fork to Boost Security and Capacity

BNB Chain has activated its Pasteur hard fork on the BNB Smart Chain (BSC) mainnet. The upgrade aims to strengthen the network's bridge, staking, and governance security while increasing block capacity without altering the 450-millisecond block time.

The Pasteur hard fork combines three BNB Evolution Proposals: BEP-682, which rejects duplicate validator entries during cross-chain light-block verification; BEP-695, which tightens controls involving validator key rotation, slashing, and governance voting; and BEP-675, which changes how specialist builders submit blocks to validators.

According to BNB Chain, the upgrade prevents validators from being counted more than once in bridge approvals, removes authority from old validator keys, and restricts voting from addresses that have been blocked. It also introduces a new route for block submission, allowing builders to submit already-executed blocks.

In tests conducted on QANet, an internal environment designed to mirror BSC's geographically distributed validators, the new route increased throughput by about 88%, from 1,237 to 2,324 transactions per second. The average gas used per block rose from 46.35 million to 84.15 million.

BNB Chain cautioned that these figures came from a controlled test workload and were not mainnet measurements. The Pasteur hard fork follows previous upgrades centered on reducing block times, including the Maxwell hard fork in June 2025 and the Fermi upgrade, which brought BSC's average block time down to 450 milliseconds.