Ethereum co-founder once again demonstrates that his true passion lies in cryptographic experiments, not market marketing. Vitalik Buterin has assembled a working prototype of an anonymous billboard with moderation, operating on the basis of zero-knowledge proofs. He jokingly noted that, as usual, he chooses curious side projects instead of directly promoting ETH.
Buterin described his approach with the term vibe coding: he formulated the task in simple words, and AI tools wrote a significant portion of the code for him. The project is built on Aztec, a privacy-focused blockchain using Ethereum's cryptographic infrastructure. This is not just a toy, but a fully functional prototype demonstrating how to combine anonymity of publications with the ability to censor unwanted content.
Return to the idea of privacy
The concept of an anonymous bulletin board with moderation was first described by Buterin back in 2022 in an essay on zero-knowledge proofs. The essence is simple: everyone posts anonymously, and moderators can remove violations without knowing the authors' identities.
Buterin regularly returns to the topic of privacy protection. Earlier this month, he warned that the revived EU initiative Chat Control threatens everyday cybersecurity by requiring checks of personal correspondence for prohibited content. He is convinced: privacy tools need to be protected more strongly, as relaxations will result in a loss of security. His large-scale Lean Ethereum roadmap is built on similar cryptographic principles.
How the billboard works
In the aztec_experiments repository on GitHub, there are three working prototypes: a token contract, an oracle for voting, and the billboard itself. The billboard relies on cryptographic "nullifiers" based on the poseidon2 hash function. They confirm the user's right to publish and block duplicate posts without revealing the author.
Before sending data to the blockchain, a private function checks with the associated token contract: does the user have the right to write? Buterin detailed the entire process in the first post of the thread. The term vibe coding was previously popularized by Andrej Karpathy, who recently joined Anthropic.
Buterin's usual style
A humorous post appeared on the demo version of the billboard: the author asked why Buterin is interested in curious projects instead of developing his own coin. There is a pattern in this joke. In 2026, Vitalik devoted almost all his time to third-party projects far from Ethereum's development path. Among them were a task for recognizing anonymous authorship, eventually solved by independent researchers, and the first chapters of a novel about decentralized governance.
Ethereum's price this year is noticeably lower than the peaks of the previous cycle, and Wall Street is much more willing to discuss ETH's bullish prospects than the co-founder's side projects. This does not seem to bother Vitalik: he finds cryptographic experiments more interesting than publicly supporting Ethereum.
Buterin has 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 the 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.
Analyst's opinion: While the market expects loud statements from Buterin about the price of ETH, he is methodically building the future of private computing. This prototype is not a distraction from the main task, but rather its essence. Ethereum is becoming a platform for confidential applications, and such projects are the best proof of that.