Author: imToken
In the traditional perception of many, Ethereum's core positioning has always been that of a "world computer" or "global settlement layer."
Over the past decade, it has indeed been responsible for executing smart contracts, supporting DeFi, and underpinning NFTs, effectively becoming a programmable financial and application execution layer.
But on March 12, Vitalik Buterin proposed a refreshingly novel perspective—the crypto industry may have overcomplicated the practical uses of blockchain. The most fundamental value of Ethereum might not be the smart contract functionality we have always emphasized, but an extremely simple primitive:
A cryptographically secure, globally shared "public bulletin board."
Many users might wonder: from "computer" to "bulletin board," is this a functional regression, or is there another angle to consider?
I. The "Global Shared Memory" Behind the "Bulletin Board"
The so-called "public bulletin board" is, as the name implies, centered on data availability.
It's simple to understand: imagine a giant bulletin board posted in a central square, readable by anyone, irrevocable, uncensored, and what is referred to here is simply a bulletin board on a global scale: users worldwide can confirm that the data indeed exists, even the most powerful government cannot erase it, and no administrator can prevent you from publishing compliant content.
Ultimately, many digital systems, such as secure online voting and software version control, have a core need not for complex financial transactions, but for an anti-censorship, publicly verifiable data publishing space. This is precisely the "bulletin board" long sought in the field of cryptography:
- Secure voting systems. Traditional electronic voting relies on centralized databases, which are at risk of tampering. Publishing voting records to Ethereum allows anyone to verify the results, while the privacy of the votes is protected by cryptography;
- Certificate revocation systems. Revocation lists for HTTPS certificates, software signing certificates, etc., need a publicly accessible, tamper-proof data source. Blockchain is naturally suited for this role;
- Multi-party coordination and governance. Open-source projects, decentralized governance, community funds—these scenarios require multiple parties to collaborate without trusting each other. Ethereum can serve as a neutral coordination layer to publish data and verify actions;
These scenarios share a common characteristic: they don't require Ethereum to "run" anything, only to "remember" something. Vitalik therefore gave a more precise ultimate definition: Ethereum is global shared memory.
Anyone can write to it, anyone can read from it, and no one can unilaterally erase it—not a company, not a government, not even Vitalik himself.
This positioning also corresponds to a clear technical path. The 2024 EIP-4844 (Blob data) was the initial scaling of this bulletin board. The full rollout of PeerDAS (Peer Data Availability Sampling) in 2026 expanded the "area" of the bulletin board a hundredfold. Ethereum is no longer fixated on the TPS of the main chain, but is committed to becoming the world's largest capacity, highest security notarization center, a foundational layer providing globally shared data availability.
II. AI is Here, Making the Public Bulletin Board More Necessary
Understanding the essence of the "bulletin board," and looking at the arrival of AI, reveals these are not two separate things, but two sides of the same coin.
Objectively speaking, the "bulletin board" line of thinking is actually quite related to the current impact of AI on Web3. Because increasingly, people's daily number of conversations with AI has surpassed conversations with any single human. But current AI services bind everything you ask, when you ask it, and how many times you ask it, to your real identity.
For example, using ChatGPT requires an email and credit card; calling the Claude API leaves clear billing records; every prompt is a digital trace pointing back to you.
Therefore, Vitalik and the Ethereum Foundation's AI lead, Davide Crapis, jointly proposed ZK API Usage Credits in February 2026, aiming to use zero-knowledge proofs to enable anonymous calls to AI large models. The logic of the proposal is clear:
A user deposits funds (e.g., 100 USDC) into a smart contract, which records this deposit in an encrypted list on-chain. Thereafter, each time the user calls an AI API, they do not need to expose their identity; they only need to generate a zero-knowledge proof proving "I have the right to use this credit" to complete the call.
What does this scheme require? Precisely a public bulletin board, a publicly verifiable, immutable data layer, to record "who has how much credit," without recording "who is who."
Simultaneously, the proliferation of AI Agents brings another new problem: how can these automatically running programs achieve economic collaboration amongst themselves? When one AI Agent needs to call the service of another, it needs to pay, establish credit, handle disputes—but it has no bank account, no legal identity, and no "real-name information" trusted by centralized platforms.
Ethereum, as an economic coordination layer for AI Agents, provides a natural answer. Agents can initiate transactions on-chain, stake collateral, establish verifiable reputation records—all of this built upon the transparent data layer provided by that "bulletin board."
In a broader framework, this positioning of the relationship between Ethereum and AI is even one of integration—as AI's capabilities grow stronger, the needs for privacy protection, verifiability, and decentralization become more rigid.
Therefore, Ethereum is not competing with AI; it aims to become the most needed infrastructure in the AI era: a public data layer that anyone can write to, anyone can trust, and no one can shut down.
III. Is the "Smart Contract" Narrative No Longer Enough?
Perhaps in Vitalik Buterin's vision, the majority of future Ethereum users might not be "humans," but AI Agents.
So this shift in positioning from "world computer" to "bulletin board," while easily misinterpreted as lowering expectations, is actually the opposite in understanding.
"World computer" is a narrative from an internal perspective, asking "what can our technology do?" while "bulletin board" is a perspective from external demand, asking "what does the world truly need?"
This perhaps also benefits from the people Vitalik encountered at cryptography conferences—those voting system researchers, certificate protocol designers, privacy tool developers. They had no interest in blockchain or Ethereum, but the things they needed were exactly what Ethereum could provide.
Therefore, the author believes Ethereum is indeed gradually becoming more realistic, as this is the proper stance of a mature technology: it no longer tries to define application scenarios, but instead refines itself into a sufficiently reliable piece of infrastructure, waiting for the scenarios that truly need it to naturally grow.
Just as TCP/IP does not explain what the internet can do, but without TCP/IP, the internet can do nothing.
From this perspective, this is perhaps Ethereum's moment of "looking inward when actions don't yield results" (行有不得, 反求诸己).
After all, the core, most irreplaceable value of blockchain has always been that truth which does not shift according to anyone's will. This means that no matter how fast AI evolves, no matter how blurred the line between reality and illusion becomes, as long as this bulletin board remains, humanity will have a place to store "truth."
This, perhaps, is Ethereum's most honest act of self-positioning.
