Vitalik Buterin has built a prototype for an anonymous billboard on the Aztec Network. The project combines zero-knowledge proofs, ETH deposits, and AI moderation. Buterin described the work as a 'vibe coding' exercise, and the details were published today on Crypto Briefing.
How the billboard works
The prototype lets anyone post a message anonymously — but not for free. Users deposit ETH to submit content, and a zero-knowledge proof verifies the deposit without revealing the sender's identity. An AI moderation layer then checks the message for obvious spam or abuse before it goes live. The whole thing runs on Aztec, a privacy-focused layer-2 for Ethereum that supports ZK-SNARKs.
It's a simple idea with a few moving parts. The ETH deposit acts as a spam deterrent — posting costs something, even if no one knows who you are. The AI filter handles the moderation side, though Buterin hasn't detailed how strict that filter is or what happens to rejected posts.
Why Aztec
Aztec Network is built for exactly this kind of use case. It's a layer-2 rollup that natively supports private transactions and smart contracts using zero-knowledge proofs. That makes it a natural fit for an anonymous billboard where the whole point is to separate the message from the messenger. Buterin has been a vocal supporter of privacy tech on Ethereum, and this prototype is a hands-on example of what that looks like in practice.
The choice also sidesteps the congestion and cost of Ethereum mainnet. Deposits on Aztec are cheaper and faster, which matters for a billboard that could see a lot of small transactions.
The 'vibe coding' approach
Buterin called this a 'vibe coding' project — his term for building something quickly without a formal spec or roadmap. It's not a polished product. It's a prototype that shows what's possible when you stitch together ZK proofs, a payment layer, and AI moderation. The code is presumably rough around the edges, but the concept is clear.
This isn't the first time Buterin has tinkered with privacy tools. He's previously discussed anonymous voting systems and private DAO participation. The billboard feels like a natural extension of that thinking — a public square where identity is optional.
Right now it's just a prototype. Buterin hasn't announced any plans to deploy it on mainnet or open it up for wider use. The Crypto Briefing post doesn't mention a timeline or a repository. That leaves the project in a familiar place for many of Buterin's experiments: a proof-of-concept that could either fade into a blog post or spark something bigger.
Whether the anonymous billboard ever goes live depends on community interest and whether someone picks up the code and runs with it. For now, it's a neat demo of what ZK tech can do when you let yourself just build.
