Ethereum co-founder Vitalik Buterin has built a small anonymous billboard demo using zero-knowledge proofs and Aztec, a privacy-focused network that runs on Ethereum's underlying cryptography. According to reports from CoinDesk, Buterin called the project 'vibe coded', describing the intended behavior in plain language and letting AI tools write much of the code. The GitHub repository, named aztec_experiments, holds three working prototypes including a token contract, a voting oracle, and the billboard itself. As reported by CoinDesk, the demo was shared on July 19 and combines zero-knowledge proofs, ETH deposits, and AI-powered content moderation into a single experimental application built on the Aztec Network.
The billboard relies on cryptographic nullifiers built with a hashing method called poseidon2, which confirm a poster's right to post and block double-posting without revealing an identity. As reported by CoinDesk, a private post function checks eligibility against a linked token contract before anything reaches the chain. The new prototype layers several components together, with users making ETH deposits to participate, creating a financial disincentive against spam and abuse. An AI system then scans posts for policy violations, and the zero-knowledge proof architecture ensures that even when the AI flags something, the poster's identity stays cryptographically shielded. This approach echoes vibe coding, a term popularized by Andrej Karpathy before he recently joined Anthropic.
Buterin sketched the anonymous billboard concept in a 2022 essay on zero-knowledge proofs for privacy, imagining a message board where anyone could post anonymously while a moderation system could still block rule violations without learning who posted what. According to reports from CoinDesk, Buterin keeps returning to this privacy theme, earlier this month warning that the EU Chat Control revival threatens everyday cybersecurity. He argued that private tools need stronger protection, not weaker rules, with his broader Lean Ethereum roadmap leaning on similar cryptographic building blocks. The broader context matters, as privacy in crypto has been a contentious topic, particularly after US regulators sanctioned Tornado Cash in 2022 and pursued legal action against its developers.
The billboard's demo carried a joke asking why Buterin is always doing fun things instead of pumping his own coin, fitting a pattern where Vitalik spent much of 2026 on side projects unrelated to Ethereum's price. As reported by CoinDesk, these included an anonymous authorship challenge that outside researchers eventually solved, plus early chapters of a decentralized governance novel. The timing sharpened the joke as Ether has traded well below its prior cycle highs this year, with Wall Street's bull case for ETH drawing far more attention than any single side project. Buterin described the project as a rapid 'vibe-coded' experiment and acknowledged the demo contains 'nontrivial' functionality but stressed it remains under active development.
Whether the billboard demo grows beyond a prototype remains unclear, but Buterin's GitHub history suggests these side projects are not slowing down. According to reports from CoinDesk, Buterin has even mentioned writing a fantasy novel under a verified pseudonym, stating he would do this if his authorship could someday be proven the same way without exposing his real identity. The cryptography experiments continue to demonstrate his focus on privacy and decentralized technologies over traditional marketing approaches for Ethereum promotion. There are no plans for a production deployment or a token launch for this particular project.
