Vitalik Buterin warns against overloading Ethereum consensus

Ethereum co-founder Vitalik Buterin has published a lengthy blog post warning of the dangers of “stretching” Ethereum’s consensus past its core functions of validating blocks and securing the network. 

Ethereum consensus is the process whereby blocks are validated by the proof-of-stake mechanism implemented in September 2022 with “the Merge.”

In a May 21 blog post titled “Don’t overload Ethereum’s consensus,” Buterin warned that using Ethereum’s network consensus for other things could bring “high systemic risks to the ecosystem and should be discouraged and resisted.”

The Ethereum co-founder was essentially promoting the preservation of the blockchain’s minimalism.

Don’t overload Ethereum’s consensus:https://t.co/07tzyCrZcJ

— vitalik.eth (@VitalikButerin) May 21, 2023

Buterin noted that over the years, a number of proposals or ideas had floated around that suggested using the Ethereum social consensus for other purposes, such as price and data oracles, re-staking initiatives, and using layer-1 soft forks to recover layer-2 projects should they have issues.

“There is a natural urge to try to extend the blockchain’s core with more and more functionality because the blockchain’s core has the largest economic weight and the largest community watching it, but each such extension makes the core itself more fragile.”

However, Buterin said that a certain subset of these techniques could bring “high systemic risks” to the ecosystem such as bugs or an intentional 51% attack.

Some high-risk examples include creating ETH/USD price oracles in which ETH holders or validators can be bribed to vote on, which may result in a “fork out the bad participants’ money” if there is disagreement.

He however acknowledged a need for better oracles, proposing a case-by-case approach because various problems are “inherently so different” from each other.

Overall, Buterin said that any expansion of the “duties” of Ethereum’s consensus increases the costs, complexities, and risks of running a validator.

Related: Buterin weighs in on zk-EVMs’ impact on decentralization and security

Application-layer projects “taking actions that risk increasing the “scope” of blockchain consensus to anything other than verifying the core Ethereum protocol rules,” should be treated with caution, he said before summarizing:

“We should instead preserve the chain’s minimalism, support uses of re-staking that do not look like slippery slopes to extending the role of Ethereum consensus, and help developers find alternate strategies to achieve their security goals.”

The Ethereum consensus mechanism switched from proof-of-work to proof-of-stake in September last year. Additionally, staked Ethereum has only just been released for withdrawal with the Shapella upgrade on April 12. This explains the increased scrutiny of validator roles and security risks on the world’s largest smart contract network.

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