Ethereum (ETH) Ends 8-Year Poseidon Push for Standard Hashes

Ethereum News

As of Aug. 14, 2026, Ethereum (ETH) has ended its eight-year effort to integrate Poseidon, a hash function built for zero-knowledge systems, and is returning to established SHA and BLAKE2s standards at layer 1. The decision, disclosed by Ethereum Foundation researcher Justin Drake, closes one of the network's most persistent cryptographic experiments and redirects engineering work toward algorithms that have already survived years of public review. The reversal underscores how quickly engineering assumptions can change when proving systems mature. Earlier, custom hashes were viewed as necessary to reduce proving overhead; now the priority is audit history, not narrow efficiency gains. That does not remove zero-knowledge technology from the roadmap, but it changes which primitives are considered safe enough for base-layer use. It also reduces dependence on code that has not been stress-tested across multiple independent implementations. The foundation coordinates core research across the Ethereum ecosystem, so the shift carries weight beyond a single client team. Poseidon was pursued because early zero-knowledge proving systems treated conventional hashing as expensive, but the technical case has weakened as binary-field mathematics improved. The Binius proof system appeared in 2023, and Flook followed in 2024, creating a path for ordinary hardware to process conventional hashes with far less overhead. The stated benchmark says a standard laptop can now handle as many as one million conventional hash operations per second with minimal extra load. That changes the cost-benefit calculation for Ethereum: instead of relying on a specialized, less-reviewed hash, developers can accept standard hashes while keeping proof generation practical. The move is also a protocol-cryptography decision, not a commercial event; it is unlike an airdrop or a race toward an all-time high. For builders, the immediate signal is that future zero-knowledge workloads should be planned around mature primitives. For the foundation, it means writing off years of Poseidon-specific development cost and re-centering the roadmap on security assumptions that external researchers can audit more easily.

Adam Back, the Hashcash creator and Blockstream CEO, moved quickly to endorse the pivot, giving Ethereum (ETH) a public validation from one of cryptography's most conservative voices. Responding to Drake, Back said he had never trusted custom zero-knowledge-optimized hashes because they had not received sufficient global scrutiny. He framed prover-friendly designs as likely to become unusual and under-reviewed constructions, adding that his own principle has always been maximum reliability. In his telling, even before general-purpose provers became common, he preferred to pay the higher proving cost associated with standard hash algorithms rather than rely on immature code. He also suggested that the industry should have moved away from experimental algorithms earlier, positioning the Ethereum decision as a delayed correction rather than a sudden reversal. The public exchange between Back and Drake matters because it turns a technical roadmap adjustment into a broader lesson about cryptographic governance. When base-layer security is at stake, the default should be broad review and conservative assumptions, especially in systems intended to support long-lived value and programmable settlement. That stance now looks better aligned with the network's new direction. The technical validation came from binary-field breakthroughs rather than ideology: Binius in 2023 and Flook in 2024 reduced the penalty for using conventional hashes, removing the main practical reason Poseidon had been pursued. The result is a rare case where a long-running engineering bet is abandoned not because of a security incident, but because the performance argument collapsed. For Ethereum, the endorsement matters because Back represents a proof-of-work and cypherpunk lineage that often emphasizes caution over novelty. For the wider zero-knowledge field, it may encourage teams to revisit custom primitives that were adopted mainly for efficiency. The change is also distinct from market mechanics such as automated market maker liquidity or atomic swap execution; it is about the cryptographic foundation under future scaling tools. The approved schedule now puts the emphasis on delivery rather than experimentation.

COINOTAG's analysis ties both developments to one arc: Ethereum (ETH) is trading specialized efficiency for auditable cryptography. The Ethereum Foundation's approved roadmap text functions as the changelog for this pivot: it halts Poseidon at layer 1, returns hashing to SHA and BLAKE2s, starts post-quantum protection with LeanVM in 2027, and targets full base-layer completion in 2028. For node operators, the announced impact is a shift in expected proving and hashing stacks from Poseidon-specific paths to standard-hash-compatible workloads, with dates rather than a specific activation block currently defining the schedule. This makes security review the controlling constraint for the next phase of AltVM and zero-knowledge deployment.