Vitalik Buterin Names How Ethereum Avoids DoS Risk

Ethereum (ETH) founder Vitalik Buterin has explained how the blockchain prevents denial-of-service (DoS) attacks. Buterin’s explanation comes as a response to a question from a user who expressed frustration with the contract size limit on Ethereum.

Network stability depends on data efficiency

According to Buterin, the limit on Ethereum exists as a safeguard to prevent DoS attacks. Notably, very large contracts are expensive to store in nodes, transmit or process. Thus, if there is no limit, a malicious attacker could easily deploy huge contracts that deliberately slow down the network.

Once the network is destabilized, it could give the attacker ample time to carry out fraudulent acts on-chain. Buterin is emphasizing that the size limit is not an arbitrary rule but a safety and scalability constraint to protect users.

The Ethereum founder, however, hinted at a possible change in the future. This will depend on improvements to the Merkle Patricia Trie, which currently has efficiency limitations.

“When we change the tree…we will be able to fix this and potentially have unlimited size contracts,” he stated.

Buterin suggests that plans are on to change how Ethereum stores its data to the EIP-7864’s unified binary tree upgrade. This will make state access and storage more efficient while reducing the DoS risk caused by large contracts.

This is different from the EIP-7907, which has increased the contract size limit by about 10 times the original size.

Ethereum gas costs will apply despite future upgrades 

It is worth pointing out that even when the size limit is resolved, users will still have to deal with gas costs. For clarity, deploying a contract costs gas per byte of code. The cost, as per Buterin’s explanation, is approximately 82kb.

This signals that if users get an “unlimited contract size” on Ethereum, it does not mean that it would be free. The developers might have to rethink deployment gas pricing to fit the new reality.

Meanwhile, the blockchain is already planning the next upgrade for 2026, termed “Hegota. Part of the key focus of the upgrade will include state management, execution-layer optimization, and Verkle Trees.