- Ethereum Foundation abandons Poseidon hash for standard SHA-2/BLAKE in its base layer, citing advances in SNARK proofs.
- Justin Drake announced the decision on August 13, ending an 8-year research effort into SNARK-friendly hashes.
- New binary-field proof systems like Binius and Flock make traditional hashes as efficient as Poseidon in zero-knowledge circuits.
- Deployment timeline targets a production-grade leanVM by 2027 and consensus, data, and execution layer rollouts by 2028.
The Ethereum Foundation has made a pivotal move in its long-term security strategy by stepping away from the Poseidon hash function, a custom-built cryptographic primitive once favored for its efficiency in zero-knowledge proofs. The shift, confirmed by researcher Justin Drake, signals a broader industry trend toward conservative, battle-tested algorithms as the threat of quantum computing looms larger. Instead of relying on specialized hashes, Ethereum will now lean on established standards like SHA-2 and BLAKE, which have decades of scrutiny behind them.
Drake announced the decision on August 13, describing it as the culmination of an eight-year research journey that began in 2018 when the Foundation started funding “SNARK-friendly hashes.” Poseidon, introduced in 2019, quickly became the dominant choice for optimizing zero-knowledge circuits. However, recent breakthroughs in proof systems have rendered the original rationale for such specialized hashes obsolete. As Drake put it, “traditional off-the-shelf hash functions like SHA2 and BLAKE2s can now match Poseidon in a SNARK. Looking back, the key wasn’t SNARK-friendly hashes, but hash-friendly SNARKs.”
Why Poseidon Lost Its Edge
The core reason behind this reversal lies in the evolution of proof systems built on binary fields. Earlier systems relied on large prime numbers, making it expensive to represent the bit-level operations of standard hashes. But innovations like Binius, introduced by Benjamin Diamond and Jim Posen in 2023, and the more recent Flock design, have changed the game. These systems work directly with binary operations, allowing traditional hashes to be verified with remarkable efficiency. According to Drake, these designs can process around one million hash calls per second on a laptop, only about 100 times slower than native CPU computation—a performance level that was previously exclusive to specialized hashes like Poseidon.
This performance parity means Ethereum no longer needs to rely on experimental cryptography to achieve scalability and security. The decision also simplifies the protocol’s architecture, making it easier to audit and maintain over the long term. For a network that handles billions of dollars in value, reducing complexity is a significant advantage.
Security Over Innovation
Drake framed the move as a bet on minimal assumptions. By using simple, well-understood hashes, Ethereum gains a foundation that can be trusted for decades. He also pointed to recent failures in more exotic cryptographic structures. “As AI becomes exceptional at cryptanalysis, the contrarian bet of avoiding riskier structures like lattices and isogenies is paying off,” he said. “The last few weeks have been brutal. Lattice-based signature schemes like HAWK and isogeny-based SQIsign, both in NIST Round 3, have suffered setbacks. Sources I trust say more problems are coming.”
The shift also eliminates the need to wait years for Poseidon to withstand cryptanalysis, accelerating Ethereum’s post-quantum roadmap. The plan now targets a production-grade leanVM by 2027, with deployments across consensus, data, and execution layers scheduled for 2028. This timeline gives developers ample room to integrate the new hashes without disrupting existing projects.
Broader Context and Industry Support
The decision has drawn praise from notable figures, including Adam Back, inventor of Hashcash and a respected cryptographer. Back publicly endorsed Ethereum’s move, highlighting its importance for the entire blockchain industry. His support underscores a growing consensus that quantum resistance is no longer optional but a necessity for any serious decentralized network.
Vitalik Buterin’s recent roadmap updates also reflect this priority, placing post-quantum security alongside privacy and AI-assisted verification. While AI is being explored to help developers verify protocol correctness, Buterin has made it clear that AI will not replace proof systems—it will only assist in building them. This pragmatic approach ensures that Ethereum remains both innovative and resilient.
For everyday users, nothing changes in the short term. Transactions, staking, and dApps will continue to function as before. The real impact lies in the network’s long-term durability. By choosing standard hashes, Ethereum is betting on simplicity and proven security over flashy but risky alternatives. This is a mature decision that could influence other blockchains still relying on SNARK-friendly hashes.
As the industry watches, the next major test will come in 2027 and 2028 when these changes are implemented in production. If standard hashes maintain their performance as systems scale, Ethereum will have made a simpler, and likely more durable, bet for its post-quantum future.