BNB Chain activates Pasteur hard fork to enhance security and transaction capacity

The Pasteur hard fork integrates three key BNB Evolution Proposals (BEPs). BEP-682 specifically targets cross-chain light-block verification by rejecting duplicate validator entries. BEP-695 strengthens controls related to validator key rotation, slashing mechanisms, and governance voting processes. Furthermore, BEP-675 modifies the procedure for specialist builders submitting blocks to validators.

Collectively, these changes aim to prevent validators from being counted multiple times in bridge approvals, revoke authority from outdated validator keys, and restrict unauthorized addresses from participating in governance votes. The upgrade also seeks to accommodate more transactions within each block during periods of high network activity.

Under the previous block-building route, builders executed transactions before submitting a block, and validators re-executed them before signing. BNB Chain noted this redundant work consumed valuable time within the network's 450-millisecond block window, sometimes leading to underfilled blocks. The new route introduced by BEP-675 allows builders to submit blocks they have already executed. Validators then verify the proposed block against consensus rules, sign it, broadcast it, and perform full execution verification afterward. Builders retain the option to use the prior method.

Preliminary tests conducted on QANet, an environment designed to simulate BSC's validators, indicated that the new route could boost throughput by approximately 88%, from 1,237 to 2,324 transactions per second. Average gas usage per block also increased from 46.35 million to 84.15 million, with block intervals and the 100-million gas limit remaining constant. BNB Chain cautioned that these figures were derived from controlled tests and may not reflect actual mainnet performance.

The Pasteur hard fork follows previous upgrades focused on reducing block times, including the Maxwell hard fork which lowered the average block time to about 0.8 seconds in June 2025, and the subsequent Fermi upgrade which brought it down to 450 milliseconds.