Ethereum Abandons Poseidon Hash in Favor of Standard Functions

The Ethereum Foundation has made a significant change to its cryptographic approach for the network's layer-one blockchain. The foundation is moving away from the Poseidon hash function, which was specifically designed for use with Succinct Non-Interactive Arguments of Knowledge (SNARKs), and will now prioritize established hash functions such as SHA2 and BLAKE2s.

This decision is driven by recent advancements in SNARK technology. The Ethereum community has focused on designing specialized hash functions to optimize SNARK efficiency, but breakthroughs have increased the speed at which proofs can be generated for conventional hashes. According to the foundation, SNARK proof performance for standard functions like SHA2 and BLAKE2s has reached approximately 1 million operations per second.

This shift in approach is significant because SHA2 and BLAKE2s are battle-tested, widely implemented hash functions with a long track record of security analysis. By relying on these established primitives, Ethereum can leverage years of cryptographic scrutiny, potentially reducing the risk of vulnerabilities that might be present in newer, specialized functions.