The Ethereum Fusaka hard fork is scheduled for late 2025.
The launch of the Ethereum Fusaka hard fork is expected in late 2025, and Ethereum core developer Tim Beiko has ruled out including the controversial EVM Object Format (EOF) upgrade.
The Ethereum Fusaka hard fork is expected in the third or fourth quarter of this year, according to an Ethereum Foundation official.
In a post on April 28, Tomasz Kajetan Stańczak, co-executive director of the Ethereum Foundation, stated that the foundation aims to deploy the upgrade of the Ethereum Fusaka network in the third or fourth quarter of 2025. However, the exact launch schedule has not been determined yet.
Stanczak stated that the controversial implementation of the EVM Object Format (EOF) for the Ethereum Virtual Machine (EVM) was expected to be part of the Fusaka network upgrade, which was later ruled out by core Ethereum developer Tim Beiko.
Beiko stated in a GitHub post on April 28: "EOF has been removed from the Fusaka network upgrade today," clarifying in a GitHub post that Ethereum developers decided there was technical uncertainty regarding its impact and risked delaying the launch of Fusaka.
Source: Tomasz Kajetan Stańczak
EVM is the program that runs Ethereum smart contracts. EOF will implement a series of protocol changes, known as Ethereum Improvement Proposals (EIPs), with profound implications for its operation mechanism. EOF offers an expandable container format and classified for different versions of the smart contract bytecode, which is verified once upon deployment, separating code from data to improve efficiency.
Related: Researcher proposes to increase the Ethereum gas limit by 100 times over 4 years.
Wrap, seal once, send.
Bytecode is a set of low-level embedded instructions. Smart Solidity contracts must be compiled into bytecode before the EVM can execute them.
EOF defines a container unit for the smart contract bytecode, replacing the current free bytecode blocks with a better-defined structure. These objects consist of:
A header starting with the hexadecimal value 0xEF00, followed by a one-byte version number to ensure upgradeability.
A section table that provides metadata about the contents of the container. Each entry consists of one byte for the entry type and two bytes for the entry size.
Sections containing the actual content, with at least one section of code and any necessary data sections — more section types can be added through future EIPs.
This structure simplifies the operation of value-added machines (EVM), allowing for higher efficiency and lower processing costs. This update will lead to a smoother development environment and easier-to-understand implemented smart contracts.
Don't jump, jump instead!
EIP-4200, one of the EIP protocols for the end file, provides an alternative to the JUMP and JUMPI instructions, allowing the program to transfer execution to any arbitrary byte offset. This type of execution chain leads to hard-to-detect errors (the value of JUMP errors may be hard to predict in some cases), and makes it easier to hide malware in data blocks and transfer the execution pointer to them.
This practice is known as dynamic jumping, and the EIP-4750 project (under review) proposes to prohibit the use of dynamic JUMP/JUMPI within smart contracts after the end of the file, and to reject it entirely during a later stage of its deployment. In its current form, this EIP project replaces these operations with CALLF (function call) and RETF (return) instructions. These new instructions ensure that destinations are encoded fixedly in the binary code, but old smart contracts before the end of the file will not be affected.
Developers who choose to use JUMP or JUMPI after the upgrade will be subject to validation of their binary code during deployment, ensuring that data or mid-instruction cannot be accessed. This validation is done through the code validation rules in EIP-3670, along with the transition table (EIP-3690), so that all destinations are verified.
As an alternative to these functions, EOF implements the RJUMP and RJUMPI functions, which require destination encoding to be fixed in the binary code. Nevertheless, the application of EOF is still not welcomed by everyone.
EOF has its haters.
EOF is an application of 12 integrated development plans (EIPs) with profound implications on how smart contract developers operate. Its proponents see it as more efficient and elegant, facilitating updates later.
However, its critics argue that it is over-engineered and adds additional complexity to an already complicated system like Ethereum. Pascal Cafersatio, an Ethereum developer, expressed his regret in a blog post on 'Ethereum Sorcerers' on March 13, stating that 'the end process is too complex', as it adds two new semantics and removes and adds more than a dozen operational codes. He also argued that it is unnecessary.
He said that all the benefits could be applied through 'incremental and less intrusive updates'. He added that the old electronic voting system would also need maintenance, 'perhaps indefinitely'.
Cafersatio also clarified that EOF requires an upgrade of the tools, threatening the emergence of new security vulnerabilities due to the large attack surface. He added that 'EVM contracts are becoming more complex due to the headers', while the weight of empty contracts is currently only 15 bytes. Another developer raised a separate point in this discussion:
Perhaps, as a key point, there appears to be a disagreement over whether major changes to the value-added machines are generally desirable. A stable virtual machine, in which people can invest to build excellent tools and applications with confidence, is much more valuable.
It seems that Cafersatio strongly supports the EOF upgrade. A dedicated poll on the ETHPulse platform for Ethereum polls showed that 39 voters holding approximately 17,745 Ether (ETH) oppose the upgrade. Only seven holders of less than 300 Ether voted in favor.
