# Ethereum Foundation Abandons Poseidon for Conventional Hashes in Its Post-Quantum Plan

Justin Drake says better proof systems made SHA and BLAKE fast enough, ending an eight-year research effort and reshaping the design assumptions of the zero-knowledge industry.

- Published: 2026-08-14T05:52:13.666Z
- Canonical: https://polylog.news/crypto/2026-08-14/ethereum-foundation-abandons-poseidon-for-conventional-hashe
- Publisher: Polylog (Crypto desk)
- Section: crypto
- Sources: [Polylog editors](https://polylog.news), [Justin Drake (X)](https://x.com/drakefjustin/status/2087905684180418733), [Cointelegraph via TradingView](https://www.tradingview.com/news/cointelegraph:94d0d54b3094b:0-ethereum-foundation-pivots-away-from-poseidon-in-post-quantum-plan/), [Cryptonews](https://cryptonews.net/news/ethereum/33293789/)

Justin Drake, a researcher at the Ethereum Foundation, [announced that the foundation is dropping the Poseidon hash function](https://t.me/cointelegraph/71605) for Ethereum's base layer and will use SHA or BLAKE instead. He called the decision a milestone for post-quantum security on Ethereum.

Poseidon belongs to a family of hash functions designed to be cheap to prove inside a succinct non-interactive argument of knowledge (SNARK), the compact proof that lets one party confirm a computation without repeating it. Conventional hashes such as SHA-2 and BLAKE were considered too expensive to prove at the volumes a hash-based post-quantum design would require, so the foundation spent years on the alternative. Drake described the effort as ["an epic 8-year, 8-figure"](https://x.com/drakefjustin/status/2087905684180418733) programme in post-quantum cryptography, and summarised the reversal by saying the answer turned out not to be proof-friendly hashes but hash-friendly proofs.

The practical argument is that SNARK performance improved faster than the cryptanalysis of new hash designs settled. Conventional hashes have decades of public attack effort behind them. Poseidon and its relatives are newer, use algebraic structure that makes them fast inside proofs, and have a thinner cryptanalytic record. Choosing the older primitive trades raw proving speed for a security assumption that far more researchers have tried and failed to break.

The change applies to Ethereum's future base-layer architecture, not to code running today. [Rollups, virtual machines and applications that already use Poseidon are not required to replace it](https://www.tradingview.com/news/cointelegraph:94d0d54b3094b:0-ethereum-foundation-pivots-away-from-poseidon-in-post-quantum-plan/) because of the roadmap decision. Drake put a production-ready leanVM, the minimal proof-oriented virtual machine at the centre of the lean Ethereum plan, at 2027, with deployment across the consensus, data and execution layers targeted for 2028. Those are long timelines, and Ethereum roadmap dates have moved before.

For the wider zero-knowledge sector the signal is commercial as much as cryptographic. Proving teams, hardware accelerator projects and rollup designers have optimised around algebraic hashes for years. If the largest smart-contract platform standardises on SHA or BLAKE at layer one, the performance targets that matter for future proving hardware change with it.

## What this means

Ethereum is choosing a more conservative design at the base layer, accepting a heavier proving workload in exchange for a hash function with a long public attack record. That shifts where proving performance has to come from: better proof systems and hardware rather than exotic primitives. The parties affected are zero-knowledge infrastructure teams and accelerator projects that tuned their roadmaps to algebraic hashes, and holders of assets on chains whose long-term security depends on quantum-resistant designs shipping on schedule. Watch the 2027 and 2028 dates rather than the announcement, because a slipped leanVM pushes post-quantum protection at layer one into the next decade.

## What to watch

- Whether major rollups and zero-knowledge virtual machine teams follow Ethereum to conventional hashes or keep algebraic ones, which determines whether proving hardware converges on a single target.
- Published proving benchmarks for SHA and BLAKE inside current proof systems, the number that decides whether the conservative choice costs users higher fees or nothing at all.
- Whether the Ethereum Foundation's post-quantum team restates the 2027 leanVM target at its next roadmap update, the clearest signal of whether the schedule is real.