As a dispute has emerged over the priority of lattice cryptography versus hash-based cryptography in Ethereum’s shift to quantum resistance, Ethereum co-founder Vitalik Buterin (비탈릭 부테린) and Zcash co-founder Eli Ben-Sasson (엘리 벤사손) have lent support to a hash-based approach. The idea is to design the core consensus structure around hash-based signatures and proof aggregation, while allowing lattice cryptography at the account and wallet layer if its security is proven.

According to blockchain outlet U.Today on Oct. 19, discussions continued on X, formerly Twitter, over the strengths and weaknesses of the two cryptographic approaches for Ethereum’s next-generation signature structure. The debate intensified after Silicon Valley venture capital firm a16z crypto raised questions about Ethereum’s hash-based signature aggregation design.

a16z crypto pointed to Ethereum’s hash-based signature system under review as relying on the recursive structure of SNARK, a zero-knowledge proof. It argued this could increase system complexity and raise coordination costs and bug risks, and that security has not been sufficiently verified. It suggested lattice cryptography should be considered as an alternative.

Gabriel Shapiro, head of legal at Delphi Labs, said it would be better to keep the current hash-based approach. He argued that if lattice cryptography’s resistance to AI-related attacks is sufficiently proven, it could be introduced in the account and wallet area through precompiles. He said the default path should remain hash-based.

Buterin agreed with that idea. He proposed a method in which users generate the signatures they want locally, process them with STARK proofs, and include them in an aggregation device. He described it as an approach through so-called EIP-8288 that can support various signature methods while reducing the burden of on-chain data input and the need to add new precompiles.

Ben-Sasson also voiced support for that direction. As a result, public discussion has increasingly favored keeping hash-based cryptography and proof aggregation at the center rather than applying lattice cryptography directly to the core consensus structure, with other cryptographic methods supported in separate layers.

At the center of the debate is how Ethereum should replace its existing signature system to prepare for advances in quantum computers. Ethereum currently uses BLS signatures to bundle validators’ signatures into one. This allows efficient processing of signatures from a large validator set, but BLS is not considered safe against quantum-computer attacks. Among known quantum-resistant signature methods, there are few alternatives that support efficient aggregation in the same way as BLS.

Buterin has proposed using recursive signatures and proof aggregation at the protocol layer to address this. Account abstraction is also a key pillar. Native account abstraction through EIP-8141 is aimed at giving accounts flexibility in transaction verification and gas payment methods, creating a foundation for accommodating various signature algorithms.

Ultimately, the debate is seen as a process of finding a balance among Ethereum’s security, scalability and implementation complexity, rather than simply choosing a single cryptographic algorithm. Still, public remarks alone do not finalize the design. A key point to watch is whether hash-based signature aggregation will become the default structure after implementation and security verification, and how lattice cryptography would be introduced in parallel.