Vitalik Buterin returns to "crypto experiments": anonymous billboard on Aztec instead of ETH marketing
Ethereum's creator surprises the community once again. This time, Vitalik Buterin has assembled a working prototype of an anonymous billboard with moderation based on zero-knowledge proofs (ZK-proofs). The project is built on Aztec — a private blockchain cryptographically compatible with Ethereum. Buterin himself jokingly noted that he once again chose a "curious side project" instead of promoting ETH.
He called his development approach vibe coding: he described the task in simple terms, and AI tools wrote most of the code for him. The aztec_experiments repository on GitHub already contains three prototypes: a token contract, an oracle for voting, and the billboard itself.
How does the billboard work? It uses cryptographic "nullifiers" based on the Poseidon2 hash function. They confirm a user's right to publish and block duplicate posts without revealing the author's identity. Before sending to the blockchain, a private function checks against the linked token contract — whether the user has the right to write. Buterin detailed the entire process in the first post of the thread.
The concept of an anonymous message board is not new: Vitalik described it back in a 2022 essay on zero-knowledge proofs and privacy. He then proposed a board where everyone posts anonymously, and moderators can remove violations without knowing the authors' identities.
The return to the topic of privacy is no coincidence. At the beginning of the month, Buterin warned: the revived Chat Control initiative in the EU threatens everyday cybersecurity. The new bill requires checking personal correspondence for prohibited content. Buterin is convinced: privacy tools need stronger protection, as concessions will result in a loss of security. His large-scale Lean Ethereum roadmap is built on the same cryptographic principles.
Buterin's usual style is to dive into "side" projects far from Ethereum's development path. In 2026, he devoted almost all his time to external endeavors: the task of recognizing anonymous authorship (which was ultimately solved by independent researchers) and the first chapters of a novel about decentralized governance. Ethereum's price this year is significantly lower than the peaks of the last cycle, and Wall Street is much more eager to discuss ETH's bullish prospects than the co-founder's side projects. Vitalik doesn't seem bothered by this: he finds cryptographic experiments more interesting than publicly supporting Ethereum.
Buterin even suggested that he might one day release a fantasy novel under a pseudonym: the same cryptography would prove that he wrote the book, but no one would know his name. Whether the billboard will remain a prototype is unclear. Judging by the history of changes on GitHub, Buterin continues to experiment just as actively.
My analysis: Another "side" project by Buterin is not just a genius's hobby. It's a signal to the market: the founder of Ethereum is systematically developing privacy infrastructure that could become the foundation for a new generation of decentralized applications. Investors who ignore these "strange" experiments risk missing the next big trend in the crypto industry.