Dencun Upgrade to be Activated on the Main Network at 21:55, only a few hours left before the upgrade. As the largest fork since the Ethereum Merge, this article aims to provide users with a 3-minute summary of the changes in the Dencun Upgrade.
Table of Contents:
1. EIP-4844: Ethereum Extension Solution Proto-Danksharding
2. EIP-1153: Temporary Storage
3. EIP-5656: MCOPY Opcode
4. EIP-6780: SELFDESTRUCT Opcode
5. EIP-7044/7055: Staking Improvement
Why is it called “Dencun”? Ethereum has two types of clients – execution clients and consensus clients, each with their own set of upgrade names. For example, there is the Cancun upgrade for execution clients and the Deneb upgrade for consensus clients. Combining them gives us the name Dencun.
Additionally, the Dencun upgrade includes 5 EIP proposals. This is a significant step forward for Ethereum scalability, which has been ongoing for 2 years and introduces “blob” as a way for Rollup to release transaction data, laying the foundation for future scalability.
The blob will reduce the cost of Rollup by 10-50 times (yet to be confirmed) as Rollup will no longer directly release data to the Ethereum block. Furthermore, as Rollup data will no longer compete for normal block space, the cost of other L1 transactions should also decrease.
Note: The blob is primarily used to reduce the cost of data storage on L2 (data storage costs previously accounted for over 90% of L2 transaction gas consumption), thereby reducing the gas fees on Ethereum L2, not directly reducing gas fees on the Ethereum mainnet.
This is a long-term proposed change by application developers (especially Uniswap), which adds a new type of storage in the EVM. Previously, data could be stored in short-term storage (cheap, in memory) or long-term storage (expensive), but EIP-1153 introduces the option of temporary storage.
This type of storage persists throughout the transaction but ceases to exist after the transaction is completed, making reentrancy attack protection cheaper and unlocking a new set of smart contract designs without increasing state bloat. Many applications/contracts are expected to use these opcodes, including Uniswap V4. Application developers have also widely requested the use of these opcodes as almost every contract uses memory copying and requires a significant amount of gas to complete. The opcode simplifies the process and reduces costs, making smart contracts more efficient.
The SELFDESTRUCT opcode was initially intended to reward developers for deleting state from the chain. However, this opcode brought more problems than benefits, so EIP-6780 restricts the functionality of the SELFDESTRUCT opcode to specific scenarios.
EIP-7044 makes staking withdrawal easier as the pre-signed exit messages will now be valid indefinitely. EIP-7045 extends the windows in which validators can provide proofs, speeding up block confirmation times (LMD-GHOST will be faster).
Overall, EIP-4844 is the biggest change in this hard fork so far, significantly reducing costs and providing a better user experience. Temporary storage and MCOPY will further reduce costs, especially on L1. Good luck to the core developers, and we look forward to a smooth upgrade.