Quick look at Ethereum’s latest DenCun upgrade

Ethereum's latest DenCun upgrade overview.

On early morning today, Ethereum developers confirmed the upcoming major network upgrade, which is named Dencun. Dencun is a combination of Cancun and Deneb. Cancun is the name of the Ethereum execution layer upgrade, while Deneb is the name of the protocol layer upgrade. Therefore, the Cancun upgrade and the Deneb upgrade are collectively referred to as the Dencun upgrade.

This upgrade includes five EIPs aimed at adding more data storage and reducing costs. The upgrade is based on EIP-4844, which is intended to introduce a new transaction type that can accept “blobs” data that is short-term persistently stored on beacon nodes. This improvement can free up more space to scale the blockchain and is forward-compatible with the Ethereum expansion roadmap.

EIP-4844 is of far-reaching significance. Full data sharding takes a long time to implement and deploy, but based on rollup, sharding can be implemented at low cost. EIP-4844 is expected to reduce the cost of rollup by an order of magnitude. Developers believe that this feature can keep Ethereum competitive without sacrificing decentralization.

This upgrade is expected to reduce the gas fees of L2 rollup.

EIP-1153 introduces a temporary storage opcode. Using temporary storage, it will be discarded after each transaction is processed. The value of temporary storage will never be serialized to storage. The Optimism team explained the motivation behind this proposal, stating that it can save users up to an estimated $3 million in gas costs on Uniswap alone.

The benefits of this proposal include:

  • The temporary storage opcode is considered separately, so updating it does not inadvertently cause disruption.
  • Clients do not need to load the original value.
  • Storage slots do not need to be cleared after use.
  • Does not change the semantics of existing operations.

Simplify gas accounting rules.


EIP-4788 can improve the design of bridges and stake pools. This proposal will publish the beacon chain block root in the Ethereum virtual machine. The beacon chain block root (Roots of the Beacon Chain Blocks) is a cryptographic accumulator used to prove arbitrary consensus states.

After the introduction of this proposal, the EVM public beacon chain block root can allow access to the Ethereum consensus layer with minimal trust. Due to this feature, dApp use cases can improve their own trust assumptions, making the development of applications such as Staking Pools and smart contract bridges easier.


EIP-5656 introduces a new instruction that allows developers to copy specified memory regions.

This proposal makes changes to the code related to the Ethereum Virtual Machine. Memory copying is a basic operation in other production environments, but implementing this feature on the EVM would incur gas costs. This proposal will provide an efficient EVM instruction for copying memory regions in Ethereum, which is very useful for various computationally intensive operations (such as EVM 384), where memory copying is identified as a significant cost.


EIP-6780 changes the function of the SELFDESTRUCT opcode. Previously, this opcode would make significant changes to the state of an account, especially by removing all code and storage. Developers have considered removing the SELFDESTRUCT opcode in the past, but this proposal adopts a different solution.

EIP-6780 will attempt to keep some common uses of SELFDESTRUCT effective, while also reducing the complexity of EVM implementation changes from contract version control.

In terms of its ultimate effect, this proposal removes code that could terminate smart contracts.

There is currently no exact date for the upgrade, but it is expected to be launched at the end of 2023.