Ethereum Hash Function Debate Shifts Focus to Security and Speed
Ethereum developers are reevaluating their hash function choices after Flock, a new post-quantum proof system, removed the need for circuit-friendly designs. The debate focuses on security and speed rather than efficiency within zero-knowledge circuits.
The five leading candidates are SHA-2, SHA-3/Keccak, BLAKE2, BLAKE3, and a modified SHA-2 variant. Each has its strengths and weaknesses: SHA-2 is fast but vulnerable to length-extension attacks; SHA-3 offers high security margin but runs slower than SHA-2 or the BLAKE family.
BLAKE2 is one of the fastest hash functions available, with a provably indifferentiable compression function. However, it has fewer cryptanalysis papers compared to SHA-2 and SHA-3. BLAKE3 pushes performance further by reducing design rounds but strips away the indifferentiability proof, breaking compatibility with prior cryptanalysis.