Ethereum Abandons 8-Year-Old Cryptography Bet on Poseidon

The Ethereum Foundation has decided to abandon its eight-year-old cryptography bet on Poseidon due to recent advancements in proof systems. According to Ethereum researcher Justin Drake, new binary-field proof systems make SHA and BLAKE practical for use in future layer-1 designs. This shift is a reversal of the tradeoff that previously favored Poseidon's design.

Drake noted that Poseidon is not broken, but rather its performance advantage has been diminished by the improved proof systems. The Ethereum Foundation has issued no migration order or deployed fork, and users are advised to leave their wallets unchanged for now. Existing rollups and zkVMs will not require any changes.

The new binary-field proof systems, such as Binius research's construction, work naturally with 0s and 1s, closely matching Keccak's bitwise operations. This has led to significant improvements in hash throughput, with Flock's authors reporting that one M4 Max core can prove about 82,000 BLAKE3 compression evaluations per second.

The Ethereum Foundation plans to use SHA or BLAKE hashes instead of Poseidon for future L1 designs. This decision is part of a broader effort to simplify the network's design and reduce its attack surface. The shift to faster proofs also paves the way for the introduction of leanVM, which will aggregate larger data into compact proofs.