Hook
Poseidon, the ZK-friendly hash function, was supposed to be Ethereum’s computational edge. In 2023, it was the darling of the Rollup economy—embedded in the circuit logic of zkSync, StarkNet, and Polygon zkEVM. Then a rumor hit my desk: Ethereum had abandoned Poseidon after eight years of development. The source was a flash news piece with no citations, no official announcement, and a timeline that simply did not align with the cryptographic history I know. The ledger remembers what the market forgets. And here, the ledger was screaming: this narrative is broken.
Context
Let me ground this in verifiable data. Poseidon is a hash function designed specifically for zero-knowledge proof systems. It was introduced in 2019 by a team including StarkWare researchers—not by the Ethereum Foundation. The function reduces circuit constraints by up to 90% compared to SHA-256, making it essential for the efficiency of zk-Rollups. Ethereum’s role was as an evaluator and potential adopter: the Foundation funded research into ZK-friendly primitives, and Poseidon was one of several candidates for the Verkle Trie and SSZ serialization. But the narrative of ‘eight years of investment’ is a conflation of Ethereum’s broader ZK exploration (which began around 2017 with early zk-SNARKs work) with the specific lifespan of Poseidon. The hash function itself is only six years old. The difference matters.
Core
I ran a cross-reference across three sources: the Ethereum Foundation’s blog, the ethresear.ch forum, and the EIP GitHub repository. There is no official statement—zero, nil—abandoning Poseidon. There is a 2024 discussion thread about security margins, but it’s an open debate, not a decision. The core technical insight is this: Poseidon’s algebraic structure is simpler than SHA-256, which invites cryptanalysis. The community has published concerns about its long-term security, but the Ethereum Foundation has not issued a policy change. The ‘abandonment’ is likely a misreading of a specific proposal—perhaps a rejection of Poseidon for a particular EIP—blown into a general panic.
Let me put my own skin in the game. In 2017, I audited ERC20 contracts for Zeppelin. I saw integer overflow bugs that the market ignored. In 2020, I built a delta-neutral strategy on Uniswap V2 while others chased yield. The pattern is the same: the market amplifies noise, but the code tells the truth. Here, the code of every major L2 still uses Poseidon. The migration cost to, say, Rescue Prime or Monolith would be immense—hundreds of developer-years. No rational actor abandons a deployed primitive without a clear replacement. The absence of a proposed alternative in the rumor is the red flag.
Contrarian
The mainstream take is that Ethereum wasted eight years on a flawed hash function. That’s emotional, not structural. The contrarian view: Poseidon’s retirement—if it happens—is a sign of engineering maturity. Cryptography is iterative. The SHA-1 to SHA-2 migration took a decade. The transition from Keccak to Poseidon for ZK is still in its early innings. The real risk is not the abandonment, but the over-reliance on a single hash function across the entire ZK ecosystem. If Poseidon is found to have a weakness, the entire L2 market could face a systemic security freeze. That’s the tail risk the rumor obscures.
Smart money waits. FOMO money pays. The market reaction to this rumor—if it spreads—will be a short-term dip in ZK tokens (STRK, ZK, MATIC). But the structural reality is that Ethereum’s protocol layer is not dependent on Poseidon. It’s an optional optimization. The panic is a narrative liquidity event, not a fundamental change.
Takeaway
The rumor is a test. It tests whether the market can distinguish between a technical discussion and a final decision. The answer will be revealed in the first official EIP or Ethereum Foundation blog post. Until then, I treat the story as noise. Time decays options; patience decays noise. The next time you see ‘eight years of investment abandoned,’ ask: where is the evidence? The ledger remembers what the market forgets. Audit trails are the only true alpha in chaos. Structure survives where sentiment collapses.