Ethereum Foundation Abandons Poseidon, Shifts to Established Hash Functions

The Ethereum Foundation is making a significant change to its base-layer design, moving away from Poseidon as a planned hash function. This decision comes after advances in proof systems operating over binary fields have changed the trade-off between conventional hashes and specialized SNARK-friendly hashes like Poseidon.

According to Justin Drake, Ethereum Foundation core researcher, newer binary-field proof systems can handle the operations used by conventional hashes more efficiently. These systems can prove roughly 1 million conventional hash computations per second on a laptop, about 100 times slower than native CPU computation.

The proposed shift would allow Ethereum to rely more heavily on established hash functions while taking advantage of advances in zero-knowledge proof systems. A production-grade leanVM is targeted for 2027, with consensus, data, and execution-layer deployments targeted for 2028.