Crypto Security Legend Adam Back Vindicated as Ethereum Pivots Away From Custom Hash Function
After eight years and substantial resources invested in the Poseidon algorithm, Ethereum is abandoning its experimental zero-knowledge hash function and returning to established cryptographic standards—a decision backed by influential computer scientist Adam Back.
Ethereum Reverses Course on Experimental Cryptography
Ethereum Foundation researcher Justin Drake has announced the platform’s decision to discontinue development of Poseidon, a specialized hash function designed specifically for zero-knowledge systems. This represents a significant strategic reversal for the network, which had devoted eight years and substantial resources to integrating the custom algorithm. Instead, Ethereum will move to conventional cryptographic standards such as SHA or BLAKE2s—the tried-and-tested algorithms that underpin most of modern computer security.
Industry Veteran Warns Against Unproven Algorithms
Adam Back, the renowned cryptographer behind Hashcash and current chief executive of Blockstream, has publicly embraced Ethereum’s shift toward conventional approaches. Back’s perspective carries weight in the industry, given his reputation for prioritizing time-tested security practices over newer experimental methods. He expressed concern that custom zero-knowledge-optimized algorithms had not undergone sufficient peer review by the broader cryptographic community before deployment. Back emphasized his long-standing principle of favoring well-established cryptographic functions, even when they carry higher computational costs, over immature or inadequately studied alternatives. His position—that technological reliability should supersede efficiency gains—has now been vindicated by recent advances in mathematics and computing.
Mathematical Breakthroughs Reshape Proof System Economics
The rationale for Poseidon has dissolved following innovations in binary-field mathematics. The emergence of the Binius proof system in 2023 and the Flook framework in 2024 fundamentally altered the computational landscape for zero-knowledge cryptography. These systems now enable conventional hash functions to process approximately one million operations per second with minimal performance degradation, even on standard computer hardware. This breakthrough eliminated the primary technical justification for custom, optimized hashing algorithms that had previously appeared necessary for practical zero-knowledge applications.
Ethereum’s transition will occur in phases, beginning with the deployment of the LeanVM virtual machine scheduled for 2027, with complete integration into the network’s base layer targeted for 2028. The pivot represents both a strategic correction and an acknowledgment that the conservative approach to cryptographic standards was ultimately the right path—a lesson that costs the network years of development effort but prevents far greater risks associated with deploying inadequately tested cryptographic innovations at scale.
Source: Ethereum Foundation, via U.Today. Not financial advice.
This shift underscores the importance of cryptographic fundamentals in blockchain reliability—the very foundation upon which institutional adoption and long-term network security depend.