Ethereum’s Layer-1 cryptography roadmap is moving away from Poseidon, the specialized hash function long favored for zero-knowledge proof efficiency, toward established primitives such as SHA or BLAKE. In an August 13 post, Ethereum Foundation researcher Justin Drake said the change follows years of work on SNARK-friendly hashing. The shift represents a new research direction for Ethereum L1 rather than an immediate protocol replacement.
The decision fits into Ethereum’s broader post-quantum program, which now covers ECDSA account signatures, BLS validator signatures, KZG commitments and quantum-vulnerable ZK systems. Ethereum’s official quantum-resistance roadmap targets completion of core post-quantum infrastructure around 2029, while stressing that the proposed milestones remain planning targets. Full ecosystem migration could extend beyond that date.
Goodbye, Poseidon!
An epic 8-year, 8-figure rabbit hole in post-quantum cryptography reaches its dream conclusion. The Ethereum Foundation is abandoning Poseidon for L1, pivoting to SHA or BLAKE. This milestone unlocks ultimate security for lean Ethereum and foreshadows a golden…
— Justin Drake (@drakefjustin) August 13, 2026
Binary-field SNARKs change the hashing trade-off
Poseidon became attractive because traditional hashes such as SHA-256 rely heavily on bitwise operations that historically carried significant costs inside many SNARK architectures. New proof systems using binary fields are changing that equation. Instead of designing hashes around SNARK constraints, researchers can increasingly design SNARKs that process established hashes efficiently.
Recent research provides measurable support for that approach. The Flock paper, published in July, reports 42,000 SHA-256 compressions per second on one M4 Max core and more than 660,000 BLAKE3 compressions per second across 10 cores. It also reports SHA-256 proving more than nine times faster than Binius64 in its benchmarks. Standard hashing is becoming practical for workloads that previously favored specialized ZK-friendly primitives.
The security rationale is equally important. Conventional hash families have extensive histories of deployment and cryptanalysis, while newer specialized constructions require separate scrutiny. Moving Ethereum L1 toward established hashes could reduce reliance on newer cryptographic assumptions without abandoning efficient proof aggregation. Drake’s announcement does not require existing rollups or applications already using Poseidon to replace it.
Ethereum’s quantum migration remains multi-year
Ethereum’s roadmap proposes a staged transition rather than a single quantum-security fork. Milestone I* introduces a post-quantum key registry, J* adds post-quantum signature verification, L* targets quantum-safe validator attestations and real-time consensus proofs through leanVM, and M* moves toward full signature aggregation and quantum-safe blob commitments. The architecture is designed to replace vulnerable components incrementally while keeping the network operational throughout the migration.
The urgency also extends beyond blockchain. The U.S. National Institute of Standards and Technology says organizations should begin migrating to quantum-resistant cryptography now and intends to remove quantum-vulnerable algorithms from its standards by 2035. NIST’s transition framework reinforces the idea that cryptographic migration must begin years before practical quantum attacks become possible.
For validators, custodians and wallet developers, no immediate migration is required. Ethereum states that current quantum computers cannot break its cryptography today. The significance of the Poseidon decision is architectural: Ethereum increasingly intends to build high-performance proof systems around conservative, heavily studied hashes rather than designing specialized hashes around the limitations of older SNARK technology.
