Ethereum Foundation pivots to traditional hashes for post-quantum L1 roadmap

The Ethereum Foundation is abandoning the specialized Poseidon hash function for its Layer 1 (L1) roadmap, pivoting instead toward established standards like SHA and BLAKE. Announced by researcher Justin Drake on August 13, 2026, the move signals a major strategic shift in how the network will handle zero-knowledge proofs in its transition to a post-quantum architecture.

The decision comes as the Foundation moves away from "SNARK-friendly" hashes in favor of traditional hash functions. This pivot is made possible by recent breakthroughs in binary-field SNARKs, specifically systems such as Binius and Flock. These advances allow traditional hashes to be proven more efficiently than previously possible, effectively erasing the performance advantages that once made Poseidon necessary for zero-knowledge proofs.

The shift to hash-friendly SNARKs

Poseidon was developed in 2019 to reduce the computational overhead of processing hashes within zero-knowledge proofs. Traditional binary-based hashes, such as SHA-256, were historically expensive to prove, leading researchers to create specialized primitives like Poseidon that were designed specifically to be compatible with SNARKs.

However, the emergence of binary-field SNARKs has inverted this requirement. As Justin Drake noted, the key to efficiency was not creating "SNARK-friendly hashes," but rather developing "hash-friendly SNARKs." By evolving the proof system itself to accommodate existing hashes, Ethereum can now utilize cryptographic primitives that have undergone far more rigorous, long-term scrutiny by the global security community.

Security and industry implications

This transition represents a fundamental change in ZK design philosophy. By relying on heavily vetted standards like SHA and BLAKE, Ethereum reduces its dependence on newer, less-tested cryptographic primitives. This approach enhances the network's long-term security posture and simplifies the broader transition to a quantum-resistant architecture without sacrificing the performance required for L1 operations.

For the wider ecosystem, this shift clarifies the path toward a post-quantum future. While the L1 roadmap is changing, the move is focused on the core protocol level; the Foundation's current plan focuses on the underlying architecture rather than forcing a migration for all existing applications.

Roadmap to 2028

The Ethereum Foundation has established a clear timeline for the implementation of these changes. The first major milestone is the development of a production-grade "leanVM"—a minimal zero-knowledge virtual machine—which is targeted for release in 2027. Following the deployment of the leanVM, the Foundation plans to integrate these changes into L1 layer deployments by 2028.

As the network moves toward this quantum-resistant future, the industry will be watching the performance of binary-field SNARKs in production environments to ensure that the theoretical efficiency gains of Binius and Flock translate to the scale of the Ethereum mainnet.