In the past few months, the core developers of Ethereum have been working on upgrading the London network. It is an upgrade after the Berlin upgrade (forked on the mainnet in April). Although the upgrade block height of each network has not yet been determined, the EIP included in the London upgrade has been determined. According to the upgrade specification, the EIP is as follows:
- EIP-1559: Eth1.0 fee market changes
- EIP-3198: BASEFEE opcode
- EIP-3529: Reduce gas return
- EIP-3541: Reject new addresses beginning with 0xEF bytes
- EIP-3554: Difficulty bomb delayed until December 2021
Now look at the details of each EIP!
EIP-1559: Eth1.0 fee market changes
EIP-1559 is one of the most anticipated changes in the history of Ethereum, and it is also the EIP that brought the biggest changes in the London upgrade. This EIP will introduce a “basic fee ( basefee)” in the network block. It will track the gas price, which comes from the transaction that the network will accept based on the demand for block space. This means that wallets and users will be able to more easily predict the price of their transactions. In addition, EIP-1559 adds a new transaction type. Users can specify the maximum amount they are willing to pay. When they send this maximum fee to the miner, they will get the maximum fee minus the sum of the basic fee and the miner tip. The difference is refunded. Finally, this EIP will also cause some transaction fees to be burned, which is considered by most of the community to be an important improvement measure in the economics of the Ethereum network.
A simple article cannot cover the mechanism, benefits and impact of EIP-1559. This list summarizes all aspects of this EIP. There is also an issue of PEEPanEIP on EIP-1559, this is the complete video.
EIP-3198: BASEFEE opcode
This EIP is matched with EIP-1559. It simply adds an BASEFEEopcode, it returns to perform the exchange in blocks of basic expenses. This will allow smart contracts to access this value on the chain, which helps to submit fraud proofs and create trustless gas price derivatives. Through this issue of PEEPanEIP lectured by Ratan Rai Sur, readers can have a comprehensive understanding of this EIP.
EIP-3529: Reduce gas return
Another major change introduced in London is canceled opcode SELFDESTRUCTgas and reduce the return of the opcode SSTOREgas returned. Although the original intention of setting up the return was to encourage developers to clear the state when possible, the reality is that this led to the appearance of Gas Token, which increased the size of the state instead. Using these returned gas, the Gas Token can be filled up when the gas price is very low, and then get a refund for executing these transactions when the gas price rises.
In addition, gas return will also cause changes in block execution time. Before the London upgrade, up to 50% of the returned gas could be further calculated in the same block. In other words, in practice, the largest block capacity can reach 1.5 times the gas limit. EIP-2539 lowered the “Execution Gas Return” from 50% to a maximum of 20%. This change will help offset the additional block size changes introduced by EIP-1559, because EIP-1559 allows blocks to use twice the current gas limit.
EIP-3541: Reject new addresses beginning with 0xEF bytes
EIP-3541 is a simple change that lays the foundation for more extensive EVM improvements in the future. I would like to see EIP-3540. This EIP will make it impossible to deploy new contracts beginning with the 0xEF bit. Existing contracts will not be affected. After the London upgrade of the main network, the shortest byte sequence starting with 0xEF does not match the starting sequence of the existing contract, and they can be reserved as a way to identify contracts that are semantically consistent with EIP-3540. Please note: EIP-3540 will require an additional network upgrade to deploy. It is worth noting that if EIP-3540 has never been deployed, the first byte retained by EIP-3541 is also used in other schemes.
EIP-3554: 2021 difficulty bomb delayed to December 2021
EIP-3554 Delayed difficulty bomb, also known as the Ice Age. The difficulty bomb or Ice Age is a mechanism introduced by Ethereum to “freeze” mining when the network transitions to proof of stake. Since the transition of proof of stake is not yet ready, we need to postpone the bomb’s “explosion” time. This was in the past It has been carried out three times: in Metropolis (EIP-649), Constantinople (EIP-1234) and Muir Glacier (EIP-2384).
Although the previous delays were quite long, this time the core developers chose a shorter delay and postponed the difficulty bomb to December 2021. At that time, the network will either undergo a transition to proof of equity or another network upgrade.
This is the entire list of changes included in the London upgrade. The upgraded block height of the testnet and the related client release version will soon be published on the Ethereum Foundation blog.