Ethereum Foundation abandons Poseidon in post-quantum cryptography shift

The Ethereum Foundation has abandoned its post-quantum cryptography plan centered on the Poseidon hash function, citing advancements in compact proofs that have eliminated its performance edge.

Researcher Justin Drake, a core developer at the foundation, stated that recent improvements in zero-knowledge proof systems have rendered Poseidon’s efficiency gains obsolete. The shift reflects a broader reassessment of post-quantum cryptographic strategies within Ethereum’s roadmap.

Poseidon, a zk-SNARK-friendly hash function, was initially selected for its compact circuit design and suitability for blockchain applications. However, Drake noted that emerging proof systems now offer comparable or superior performance without Poseidon’s constraints. The foundation has not yet specified a replacement cryptographic method but confirmed ongoing research into alternative post-quantum solutions.

The decision underscores the dynamic nature of cryptographic research in blockchain, where rapid advancements in zero-knowledge proofs and post-quantum algorithms can quickly alter optimal pathways. Ethereum’s roadmap has increasingly emphasized scalability and security enhancements, with post-quantum cryptography viewed as a critical component for long-term resilience.

The foundation did not provide a timeline for the transition or details on how the change may impact existing development milestones. Further updates are expected as research progresses.