Ethereum Abandons Poseidon for SHA and BLAKE in Quantum Resistance Push
The Ethereum Foundation has abandoned its pursuit of Poseidon hash as the backbone of its Layer 1 (L1) cryptography in favor of established, time-tested hash functions like SHA and BLAKE. This decision marks a significant milestone in Ethereum's ongoing quest to stay ahead of the looming threat posed by quantum computers.
Poseidon was designed to overcome the inefficiencies of traditional hashes when used inside zero-knowledge proof systems (SNARKs), but recent advances in binary field SNARKs have made it possible to use these well-audited, widely trusted hashes without a performance penalty. The Ethereum Foundation will continue to see Poseidon's use in existing zero-knowledge systems.
The foundation plans to complete the development of its quantum-resistant system, LeanVM, by 2027, with sequential deployment across Ethereum's consensus, data, and execution layers slated for 2028. However, Justin Drake emphasized that these dates are targets, not guarantees.