“By implementing this limit, Ethereum can enhance its resilience against certain DoS [Denial of Service attack] vectors, improve network stability, and provide more predictability to transaction processing costs.”
The proposal aims to enforce a maximum limit of 16.77 million gas for any single transaction, nearly half of the 30 million gas limit proposed in EIP 7825. This limit, according to Buterin and Wahrstätter, will be applicable irrespective of the block gas limit set by miners or validators.
Implementation of this proposal will see transactions specifying a gas limit above 16.77 million gas get invalidated. This means that during transaction validation, transactions exceeding the gas limit will be rejected and excluded from the transaction pool. Similarly, during block validation, any block that contains a transaction that exceeds the set gas limit will become invalid.
Buterin and Wahrstätter’s chosen 16.77 million gas limit will provide a “balance between allowing complex transactions while maintaining predictable execution bounds,” as per the proposal. The authors added:
“This value enables most current use cases, including contract deployments and advanced DeFi interactions, while ensuring consistent performance characteristics.”
When implemented, the proposal will require users and decentralized applications (dApps) to split transactions with higher gas limits into smaller operations. However, Buterin and Wahrstätter expect the limit to impact a minimal number of users and dApps since most current transactions fall well below the proposed limit.
Ethereum’s current architecture allows transactions to theoretically consume the entire gas limit of a block. This architecture carries several risks.
For instance, allowing a single transaction to consume most or all of the block gas limit can make it easier for miscreants to execute DoS attacks. In DoS attacks, bad actors try to overwhelm a network through a barrage of spam transactions. This causes the network to fail to provide service to genuine users.
According to the proposal, the absence of a transaction gas limit can also lead to uneven load distribution and affect network stability.
Having variable gas usage can also cause an imbalance in load distribution across transactions in a block. Furthermore, high-gas transactions also cause longer block verification times, which can impact user experience.
According to Buterin and Wahrstätter, limiting the gas usage limit of single transactions can help reduce the risk of single-transaction DoS attacks. Essentially, the limit will set a guardrail that prevents malicious actors from using the network’s bandwidth through large spam transactions.
The limit would also ensure that gas is allocated fairly across transactions in a block, the proposal stated. The cap is also expected to make the validation of blocks “more predictable and uniform.”
The most important benefit, however, would be enhanced compatibility with zero-knowledge virtual machines (zkVMs). Encouraging transactions with hefty gas limits to be broken up into smaller chunks “allows better participation in distributed proving systems,” and enables “more predictable zkVM circuit design,” the proposal stated.
