BNB Chain schedules Pasteur hard fork on BSC mainnet for Aug. 25

Mandatory client changes before activation

All BSC mainnet nodes are required to run v1.7.7 for the hard fork. Operators also need to remove Eth EnableBAL from config.toml, as the updated client will fail to start if that setting remains in place.

The release further says TxPool OverflowPoolSlots should be removed, although that field will simply be ignored by the client. It also notes that several command-line flags are now obsolete or inactive.

Bridge and validator rules are being tightened

One of the three proposals in Pasteur, BEP-682, changes how BSC validates blocks referenced in cross-chain transfers. Under the new rules, the network verifies validator signatures before accepting information from another chain, with the goal of confirming that the required voting threshold approved the block.

A second proposal, BEP-695, focuses on validator controls and governance. After the upgrade, an old consensus key will no longer keep administrative authority after a validator rotates keys. Pending slash evictions will also follow validators to new keys, which is intended to stop validators from avoiding penalties through key changes.

The same proposal also prevents blacklisted addresses from using signature-based governance voting methods to work around direct-vote restrictions. These changes apply at the protocol and system-contract level, so existing applications do not need migration, according to the release.

New block-submission path increased test throughput

Pasteur also includes BEP-675, which changes part of the block production workflow. It allows builders to submit blocks that have already been executed, while validators first check the proposal against consensus rules, sign and broadcast it, and then complete full verification outside the most time-sensitive production path.

In QANet testing, that approach lifted throughput to 2,324 transactions per second from 1,237 TPS. The reported test results did not involve changes to the 450-millisecond block interval, and finality lag also remained unchanged.

Builders that use this path will need to operate full nodes because they are expected to produce fully executed blocks. Legacy block bids will still be supported, although they will have less time available to fill blocks.

Testnet rollout is complete, mainnet impact remains to be seen

Pasteur has been running on the BSC testnet since July 21. The next confirmed step is the mainnet activation scheduled for Aug. 25 at 02:30 UTC.

After that point, operators and developers are expected to watch whether the gains seen on QANet appear under live network conditions. BNB Chain has not confirmed a comparable mainnet performance increase in advance, and the published throughput improvements remain limited to controlled testing so far.