Ethereum Abandons Poseidon Hash Function for SHA2 and BLAKE2s

The Ethereum Foundation has made a strategic shift in its cryptographic approach for the network's layer-one (L1) blockchain, moving away from Poseidon hash function and towards established hash functions such as SHA2 and BLAKE2s.

This decision is driven by recent advancements in Succinct Non-Interactive Arguments of Knowledge (SNARK) technology, which has dramatically increased the speed at which proofs can be generated for traditional hashes. According to the foundation, SNARK proof performance for these standard functions now reaches approximately 1 million operations per second.

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