Written by: imToken
In many people's traditional understanding, Ethereum's core positioning has always been "world computer" or "global settlement layer".
Over the past decade, it has indeed been responsible for executing smart contracts, hosting DeFi, and supporting NFTs, essentially becoming a programmable financial and application execution layer.
However, on March 12th, Vitalik Buterin offered a refreshing perspective—the crypto industry may be overcomplicating the practical applications of blockchain. Ethereum's fundamental value might not be the smart contract functionality we've been emphasizing, but rather an extremely simple primitive:
A globally shared "public bulletin board" in a cryptographic sense.
Many users may wonder whether the change from "computer" to "bulletin board" is a functional regression or a result of other considerations.
I. The "Global Shared Memory" Behind the "Bulletin Board"
The term "public bulletin board" is self-explanatory; its core meaning refers to data availability.
It's easy to understand. Imagine a giant bulletin board posted in a city center square. Anyone can read it, it can't be retracted, and no one can censor it. But here we're talking about a bulletin board in a global sense: users around the world can confirm that the data actually exists, even the most powerful government can't erase it, and no administrator can stop you from posting compliant content.
Ultimately, the core requirement of many current digital systems, such as secure online voting and software version control, is not complex financial transactions, but rather a censorship-resistant and publicly verifiable data publishing space—precisely the "bulletin board" that the cryptography field has long sought.
- Secure voting system. Traditional electronic voting relies on centralized databases, which are vulnerable to tampering. By publishing voting records on Ethereum, anyone can verify the results, while the privacy of the ballots is protected by cryptography.
- Certificate revocation system. The revocation list for HTTPS certificates and software signing certificates requires a publicly verifiable and tamper-proof data source. Blockchain is a natural fit for this role;
- Multi-party coordination and governance. Open source projects, decentralized governance, community funds—these scenarios require collaboration among multiple parties without mutual trust. Ethereum can act as a neutral coordinating layer to publish data and verify actions.
These scenarios share a common characteristic: they don't require Ethereum to "run" anything, but only to "remember" something. Vitalik therefore offered a more precise ultimate definition: Ethereum is global shared memory.
Anyone can write to it, anyone can read it, and no one can unilaterally erase it—not a company, not a government, and not Vitalik himself.
This positioning also corresponds to a clear technological path. EIP-4844 (Blob Data) in 2024 was the first expansion of this bulletin board, and PeerDAS (Peer Data Availability Sampling), which was fully implemented in 2026, increased the "area" of the bulletin board by a hundredfold. Ethereum is no longer obsessed with the TPS of the main chain, but is committed to becoming the world's largest and most secure evidence storage center, a foundational layer that provides global shared data availability.
II. With the advent of AI, public bulletin boards have become even more necessary.
Once you understand the essence of "bulletin boards," you'll see that the arrival of AI is not two separate things, but rather two sides of the same coin.
Objectively speaking, the idea behind "bulletin boards" is actually quite related to the impact of AI on Web3. This is because more and more people are now interacting with AI more often than they interact with any other person each day. And now, with AI services, what you ask, when you ask it, and how many times you ask it are all tied to your real identity.
For example, if you use ChatGPT, you need an email address and credit card; if you call the Claude API, your billing records are clear, and every prompt is a digital trace pointing to you.
Therefore, in February 2026, Vitalik and Davide Crapis, the lead AI engineer at the Ethereum Foundation, jointly released a proposal called ZK API Usage Credits, which aims to enable anonymous calls to large AI models using zero-knowledge proofs. The logic of the proposal is also very clear:
When a user deposits funds (e.g., 100 USDC) into a smart contract, the contract records the deposit in an on-chain encrypted list. Subsequently, each time the AI API is called, the user does not need to expose their identity; they only need to generate a zero-knowledge proof demonstrating "my right to use this amount" to complete the call.
What does this solution need? It needs a public bulletin board, a publicly verifiable and tamper-proof data layer, to record "who has how much credit limit", but not "who is who".
At the same time, the proliferation of AI agents has brought about another new problem: how can these automated programs cooperate economically with each other? After all, when an AI agent needs to call the services of another AI agent, it needs to make payments, build trust, and handle disputes, but it has no bank account, no legal identity, and no "real-name information" that can be trusted by a centralized platform.
Ethereum, as the economic coordination layer for AI agents, provides a natural answer. Agents can initiate transactions, stake collateral, and establish verifiable reputation records on the chain, all of which are built on the transparent data layer provided by that "bulletin board".
Within a larger framework, the relationship between Ethereum and AI is even one of integration—as AI becomes more powerful, the need for privacy protection, verifiability, and decentralization becomes more rigid.
Therefore, Ethereum is not trying to compete with AI, but rather 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.
3. Is the narrative of "smart contracts" insufficient?
Perhaps in Vitalik Buterin's vision, most future Ethereum users may not be "humans," but rather AI agents.
Therefore, this shift in positioning from "world computer" to "bulletin board" may be easily misinterpreted as lowering expectations, but in reality, the understanding is the opposite.
"World Computer" is a narrative from an internal perspective, asking "What can our technology do?" while "Billboard" is a perspective from an external perspective, asking "What does the world really need?"
This may also be thanks to the group of people Vitalik met at the cryptography conference—those researchers of voting systems, designers of certificate protocols, and developers of privacy tools. They had no interest in blockchain and Ethereum, but Ethereum could provide exactly what they needed.
Therefore, I believe that Ethereum is indeed becoming more realistic step by step, because this is the attitude that mature technology should have. Instead of trying to define application scenarios, it is polishing itself into a sufficiently reliable infrastructure and waiting for the scenarios that truly need it to grow naturally.
Just like TCP/IP doesn't explain what the internet can do, but without TCP/IP, the internet can't do anything.
From this perspective, this could be seen as a case of "when things don't go as planned, look inward for the cause."
Ultimately, the core and irreplaceable value of blockchain lies in its authenticity, which is independent of anyone's will. This means that no matter how fast AI evolves, and no matter how blurred the line between reality and illusion becomes, as long as this bulletin board exists, humanity will have a place to store the "truth."
This may be Ethereum's most honest self-positioning to date.
