Ethereum L1 transitions from Poseidon to SHA2 or BLAKE2 for post-quantum cryptography

Odaily Planet Daily reports that Justin Drake has posted that Ethereum L1 will no longer use the Poseidon hash function, which has dominated since 2019, and will instead transition to traditional hash functions such as SHA-2 or BLAKE2s. This shift is driven by advancements in the field of SNARK design, moving the focus from “SNARK-friendly hashes” to “hash-friendly SNARKs.” By natively aligning with binary field operations used in traditional hashes, the proof performance of traditional hashes in SNARKs has reached one million proofs per second, with an overhead of approximately 100x. Research initiatives such as Binius and Flock have contributed to these advancements. The Ethereum Foundation’s post-quantum team is advancing this roadmap, which includes deploying a production-grade leanVM by 2027 and implementing it across the consensus, execution, and data layers by 2028. Justin Drake also noted that enhanced AI capabilities in cryptanalysis have recently undermined lattice-based schemes like HAWK and isogeny-based schemes like SQIsign, prompting the adoption of hash-based schemes for post-quantum blockchain signatures. The open-source automated research trend is also accelerating progress—SNARK.fast has already achieved 1.8 million BLAKE3 proofs per second.