BNB Smart Chain Mainnet Planck Upgrade Announcement

BNB Smart Chain Mainnet Planck Upgrade Announcement

BNB Smart Chain mainnet is expected to have a scheduled hard fork upgrade named Planck at block height 27,281,024. The current block generation speed forecasts this to occur around 12th April 2023 at 05:30 AM (UTC). The validators and full node operators on mainnet should switch their software version to  v1.1.21 before 12th April 2023.

1. Background

1.1 Who is Max Planck?

Max Planck (1858-1947) was a German physicist who is best known for his work on quantum theory. He is considered to be the founder of quantum mechanics, a branch of physics that describes the behavior of matter and energy at the atomic and subatomic level.

Planck received many honors and awards throughout his career, including the Nobel Prize in Physics in 1918.

1.2 What is a hard fork upgrade?

A hard fork is an upgrade that is not compatible with the previous release because some breaking changes are introduced in the latest release. A hard fork in BNB Smart Chain requires more than half of all validators to successfully upgrade to keep making blocks. If the existing full nodes in the network do not upgrade, they will not be able to receive and execute further blocks normally after the hard fork block height.

1.3 What happens during a network upgrade?

Logic changes will occur at block height 27,281,024 for this upgrade. After the activation of the upgrade, the blockchain is able to handle a series of new features and bug fixes.

2. How does this upgrade affect me?

2.1 As a full node operator, what do I have to do?

This release is breaking and you need to switch to  v1.1.21 . Upgrade instructions are (all the below should be done before the hardfork block height):

  1. If your node is already synced with the network, please download and compile the latest version
  2. Stop the geth process and restart it with  v1.1.21 .

2.2 What will happen if I forget to upgrade my full node in time?

If you cannot upgrade your software, you cannot sync with the upgraded BNB Smart Chain peer/validator nodes. You will not be able to connect or send transactions.

How to recover?

  1. Download and compile the latest version v1.1.21 .
  2. Stop the geth process and restart it with v1.1.21 .

2.3 As a developer, what do I have to do?

There are no changes to the EVM module. You do not need to do anything.

3. Upcoming Changes

3.1 BEP-171 Security Enhancement for Cross-Chain Module

This BEP introduces several security enhancements for the cross-chain bridge between BNB Beacon Chain and BNB Smart Chain.

To further eliminate the pervasive effects of potential issues in cross chain module, it proposes the following enhancements:

  • Upgrade IAVL proof verification to ICS23 spec.
  • Apply timer lock to massive funds cross-chain transfer.
  • Cross chain channels can be automatically paused by forged proof detection.
  • Cross chain channels can be paused by any validator in an emergency.

3.2 BEP-172 Network Stability Enhancement On Slash Occur

This BEP introduces an update for Parlia consensus to improve the stability of the network. It changes the timestamp and delay setting for offturn validators. When the validator inturn missed its turn to commit a block, the block mined by the offturn validator selected randomly would be committed as soon as possible(4 or 3 seconds).

3.3 Other Notable Changes


  • #1322 `–diffsync` is deprecated
  • #1261 debug API callTracer would have an option `withLog` to collect logs emitted during each call.


  • #1356 fix: crash on nil access when TxPool shutdown
  • #1354 fix: add some boundary check for security
  • #1377 miner: add fallthrough for switch cases