Ethereum core developers have officially removed the Poseidon hash function from their anti-quantum architecture design. Instead, the network is opting to take a step back and revisit established, time-tested names like the SHA or BLAKE algorithms. Ethereum Foundation researcher Justin Drake shared the announcement of this shift in direction on Thursday, August 14, 2026.
This transition is not due to code flaws, but is ironically driven by the network’s own innovation. Rapid progress in SNARKs technology - succinct cryptographic proof systems - has gradually erased all the performance advantages that initially drew attention to Poseidon. Previously, Poseidon was the leading candidate to power leanVM, a key infrastructure designed to enable Ethereum to efficiently verify massive volumes of blockchain activity.
This technical overhaul will not affect the Ethereum mainnet anytime soon. The entire design phase remains a long-term plan, continuing the outline of the quantum defense roadmap crafted by Vitalik Buterin. If followed, the new leanVM infrastructure is expected to enter the production-ready phase in 2027. A year later, specifically in 2028, the system will be integrated into the network’s three crucial layers - consensus, data, and execution - although this launch schedule remains tentative.
Why Revert to Old Standards
Reverting to conventional hash functions brings an invaluable asset: a proven track record. Eigen Labs CEO Sreeram Kannan noted that systems built on established hash functions have far fewer hidden attack vectors compared to alternative post-quantum approaches. Since standards like SHA and BLAKE have been tested and audited for years by the global cryptography industry, their implementation can be executed faster without navigating new risks.
This presents a sharp contrast when compared to Poseidon. Despite offering high efficiency on paper, Poseidon is still a nascent standard. Risking billions of dollars in daily transaction value on a new algorithm that has not stood the test of real-world hackers is seen as a blind gamble. Furthermore, post-quantum architecture demands a solid foundation with zero tolerance for exploit vulnerabilities.
Evidence from cross-entity collaboration shows that this conservative move is yielding tangible results. Kannan revealed that a partnership between the Ethereum Foundation, his company, and ZK-proof provider Succinct is now recording proving speeds that are 2.5 times faster. This unexpected efficiency was achieved because researchers optimized existing functions rather than building new ones.
Pragmatism Amidst the Quantum Threat
For the majority of users, the hash functions running in the background may never be visible on their crypto wallet screens. But for researchers carrying the burden of user asset security, the shift from Poseidon to SHA and BLAKE is a bold signal of pragmatism. Ahead of a future quantum computer era capable of breaking standard cryptographic security, using an old weapon that cannot break makes far more sense than forcing a new, untested sword into the actual battlefield.
As reported by Cointelegraph.
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Disclaimer: This article is for informational and educational purposes only, not financial advice. Cryptocurrency assets are highly volatile and carry significant risk. Always do your own research (DYOR) and never invest more than you can afford to lose.
