After eight years of investment, why did Ethereum abandon Poseidon?
Author: ChandlerZ, Foresight News Original title: After eight years of sharp turns, why did Ethereum suddenly abandon Poseidon? On August 13, Ethereum researcher Justin Drake wrote on X that the Ethereum Fund decided to abandon the SNARK-friendly hash algorithm Poseidon at the L1 layer and instead use traditional hash functions such as SHA2 or BLAKE2. Behind this decision is eight years of research, the accumulation of tens of millions of dollars, and a major revision to the post-quantum cryptography roadmap. Since its launch in 2019, Poseidon has been regarded as an ideal hashing scheme for applications such as zkRollup and zKVM. Its structure makes it cheaper and more efficient than traditional binary-based hash functions in SNARK circuits. But when post-quantum security became a hard requirement for Ethereum, Poseidon's limitations began to be exposed. Justin Drake said that this shift is due to groundbreaking SNARK design progress, that is, the performance of traditional hash functions in SNARK circuits is comparable to that of Poseidon, which was previously designed specifically for SNARK optimization. A single laptop can verify about 1 million traditional hash calls per second. According to the article, Poseidon has been the mainstream SNARK-friendly hashing scheme since its launch in 2019, providing security guarantees for applications such as zkRollup and zKVM. Justin Drake said that the plan shows that production-grade LeanVM is expected to be launched in 2027, the relevant deployment of the consensus layer, data layer and execution layer is expected to be completed in 2028, and the quantum team is also accelerating research related to the binary domain after the Ethereum Foundation. Why now? Traditional hashes have been difficult to enter SNARK for a long time, and the main obstacle comes from differences in computational languages. SHA2, BLAKE2s, and Keccak make extensive use of Boolean operations such as XOR and shift. Traditional SNARK usually processes arithmetic on large prime numbers, and simulating every bit operation can incur high constraint costs. Poseidon is designed directly around prime field arithmetic, with fewer constraints in exchange for higher proof speed. The cost is that the algorithm has a short history and requires continuous cryptographic analysis. The binary domain switches the underlying math to the smallest element domain containing only 0 and 1, and uses the binary domain extension to carry larger data. As a result, bit computation can directly enter the proof system. SNARK began to adapt to traditional hashes, and the technical focus changed from designing SNARK-friendly hashes to designing hash-friendly SNARKs. Binius, proposed by Jim Posen and Benjamin Diamond in 2023, shows the binary tower domain SNARK path. The Flock paper by Benedikt Bünz, Ron Rothblum, and William Wang was uploaded to arXiv on July 29, 2026. Its M4 Max benchmark is that a single core proves 82,000 times of BLAKE3 compression and 42,000 SHA- cycles per second With 256 compression and 30,000 Keccak replacements, the 10-core BLAKE3 has a throughput of over 660,000 times. According to Drake, the laptop can prove about 1 million traditional hash calls per second, which is about 100 times the cost of native CPU Boolean calculations; SNARK.fast reached 1.8 million BLAKE3 per second on M3 Max a few days ago. LeanVM in 2027, the 2028 three-tier deployment Another key reason for the abandonment of Poseidon is that the post-quantum security timeline is accelerating. “The Quantum Threat to Blockchains - 2026 Report” published by Project Eleven points out that the rapid development of quantum computers poses a serious threat to blockchain security. Once a “cryptographics-related quantum computer” (CRQC) appears, the Shor algorithm can quickly crack asymmetric cryptography such as ECDSA (used by Bitcoin and most public chains) and RSA. It is expected that Q-Day (quantum decryption day) may be between 2030 and 203...