A Quick Look at Ethereum’s Dencun Upgrade

In the early hours of this morning, Ethereum developers have confirmed the upcoming comprehensive upgrade of the network. This upgrade is named Dencun.

The word Dencun is a compound word formed by Cancun (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 called the Dencun upgrade.

This upgrade includes five EIPs aimed at adding more data storage and lowering fees. The upgrade takes EIP-4844 as the core, in addition, it also includes four improvement proposals of EIP-1153, EIP-4788, EIP-5656, and EIP-6780.

EIP-4844

EIP-4844 is at the heart of this upgrade, an improvement commonly referred to as proto-danksharding. This proposal introduces a new transaction type to Ethereum that can accept "blobs" of data stored on beacon nodes for short periods of time. This improvement frees up more room to scale the blockchain and is forward compatible with the Ethereum scaling roadmap.

The implications of EIP-4844 are profound. Complete data sharding takes a long time to complete and deploy, but based on rollup, sharding can be realized at low cost. And EIP-4844 promises to reduce rollup fees by an order of magnitude. Developers believe the feature will allow ethereum to remain competitive without sacrificing decentralization.

This upgrade is expected to reduce the gas cost of L2rollup.

EIP-1153

EIP-1153 introduces temporary storage opcodes. Temporary storage is used, which is discarded after each transaction. Values stored temporarily are never serialized to storage.

The Optimism team once explained the motivation for this proposal. On Uniswap alone, this proposal can save users an estimated gas cost of up to $3 million.

The benefits of this proposal include:

Temporary storage opcodes are considered separately, so making this update can't inadvertently break things.

The client does not need to load the original value.

Storage slots do not need to be cleared after use.

The semantics of existing operations are not changed.

Simplify gas accounting rules.

EIP-4788

EIP-4788 improves the design of bridges and stake pools. The proposal would expose the beacon chain block root in the Ethereum Virtual Machine. Roots of the BeaconChainBlocks are cryptographic accumulators used to prove arbitrary consensus states.

Following the introduction of this proposal, the EVM exposes the beacon chain root to allow trust-minimized access to the Ethereum consensus layer. Due to this feature, dApp use cases can improve their own trust assumptions, so the development of applications such as StakingPools, smart contract bridges, etc. will be easier.

EIP-5656

EIP-5656 introduces a new instruction through which developers can copy specified memory regions.

This proposal introduces changes to code related to the Ethereum Virtual Machine. In other production environments, memory copying is a basic operation, but implementing this function on the EVM will incur gas overhead. This proposal will provide Ethereum with an efficient EVM instruction that can be used to copy memory regions. This instruction is useful for various computationally intensive operations (e.g. EVM384) where memory copying is identified as a significant overhead.

EIP-6780

EIP-6780 changes the functionality of the SELFDESTRUCT opcode. Previously, this opcode made extensive changes to the state of the account, notably removing all code and storage. In the past developers have considered removing the SELFDESTRUCT opcode, but this proposal takes a different approach.

EIP-6780 will attempt to keep some common uses of SELFDESTRUCT alive while reducing the complexity of EVM implementation changes from contract versioning.

In its net effect, the proposal removes code that could terminate a smart contract.

There's no firm date for the upgrade yet, but it's expected to go live by the end of 2023.