The Ethereum Foundation is dropping the Poseidon hash function from its post-quantum security roadmap, according to researcher Justin Drake, who announced the shift on Thursday.
Established Alternatives Replace Poseidon
Drake said the foundation is turning to well-established alternatives such as SHA or BLAKE to replace Poseidon in its planned quantum-resistant architecture. A hash function converts data into a fixed digital fingerprint, allowing computers to verify that information has not been tampered with.
Poseidon had previously been considered a candidate for future post-quantum systems, including leanVM, a proposed mechanism designed to help Ethereum verify large volumes of blockchain activity efficiently. That system has not yet launched on mainnet.
SNARK advances erased Poseidon’s edge
Drake attributed the decision to rapid progress in SNARKs, which are compact cryptographic proofs that confirm computations without re-executing the underlying work. He said those advances now allow conventional hash functions to perform efficiently enough that Poseidon’s earlier performance advantage no longer applies.
The pivot reflects an engineering reassessment rather than a security failure in Poseidon itself. As proof systems improve, the case for specialised cryptographic primitives weakens against standards that have already been through years of public scrutiny.
Timeline targets set for 2027 and 2028
Drake outlined a preliminary schedule tied to the architecture shift. A production-ready leanVM is targeted for 2027, with broader deployments across Ethereum’s consensus, data, and execution layers planned for 2028. Both dates remain tentative.
Eigen Labs CEO backs the direction
Sreeram Kannan, founder and CEO of Eigen Labs, endorsed the move toward hash-based alternatives. Kannan said established hash-based systems carry fewer known attack surfaces than other post-quantum approaches, and can be deployed faster because they have already been subjected to years of public scrutiny.
Kannan also disclosed that joint work involving the Ethereum Foundation and zero-knowledge proof company Succinct had boosted proving speeds by 2.5 times, a performance gain that directly supports the case for moving away from specialised hash functions like Poseidon.
