In the traditional perception of many people, the core positioning of Ethereum has always been the "world computer" or "global settlement layer."

In the past ten years, it has indeed been responsible for executing smart contracts, hosting DeFi, and supporting NFTs. It has essentially become a programmable financial and application execution layer.

But on March 12, Vitalik Buterin made a refreshing point - the encryption industry may have overcomplicated the actual use of blockchain. The most fundamental value of Ethereum may not be the smart contract function we have been emphasizing, but an extremely simple primitive:

A "public bulletin board" shared globally in a cryptographic sense.

I believe many users will also have questions. From "computer" to "bulletin board", is this a degradation of functionality, or is there another consideration?

1. The "global shared memory" behind the "Bulletin Board"

The so-called "public bulletin board" is exactly what the word means, and the core refers to data availability.

It is also very simple to understand. We can imagine a giant bulletin board posted in the city center square, which is readable by anyone, irrevocable, and uncensored. What this refers to is just a bulletin board in a global sense: Users around the world can confirm that the data does exist, even the most powerful government cannot erase it, and no administrator can prevent you from publishing compliant content.

In the final analysis, the core requirement of many current digital systems, such as secure online voting, software version control, etc., is not complex financial transactions, but a censorship-resistant, publicly verifiable data release space. This is the "bulletin board" that the cryptography field has long sought:

• Secure voting system. Traditional electronic voting relies on centralized databases and is at risk of tampering. Publish voting records to Ethereum, anyone can verify the results, and the privacy of the votes is protected by cryptography;

• Certificate revocation system. The revocation list of HTTPS certificates and software signing certificates requires a publicly verifiable and non-tamperable data source. Blockchain is naturally suitable for this role;

• Multi-party coordination and governance. Open source projects, decentralized governance, community funds - these scenarios require multiple parties to collaborate without mutual trust. Ethereum can serve as a neutral coordination layer to publish data and verify behaviors;

These scenarios have a common feature, they do not require Ethereum to "run" anything, they only require Ethereum to "remember" something. Vitalik therefore gave a more precise ultimate definition, that is, Ethereum is global shared memory.

Anyone can write, anyone can read, and no one can unilaterally erase it, not a company, not a government, not Vitalik himself.

This positioning also corresponds to a clear technical path. EIP-4844 (Blob data) in 2024 is the first expansion of this bulletin board. PeerDAS (Peer Data Availability Sampling), which will be fully implemented in 2026, will expand the "area" of the bulletin board a hundred times. Ethereum is no longer obsessed with the TPS of the main chain, butis committed to becoming the world's largest capacity and highest security certificate storage center, a basic layer that provides global shared data availability.

2. AI is coming, public bulletin boards have become more necessary

After understanding the nature of the "bulletin board" and looking at the arrival of AI, you will find that these are not two things, but two sides of the same thing.

Objectively speaking, the idea of ​​"bulletin board" is actually closely related to the current impact of AI on Web3. Because more and more people now have more conversations with AI every day than with any other person. But with today’s AI services, what you ask, when you ask, and how many times you ask are all tied to your true identity.

For example, if you use ChatGPT, you need an email address and a credit card; if you call Claude API, the billing record will be clear, and every prompt will be a digital trace pointing to you.

Therefore, Vitalik and Davide Crapis, head of AI at the Ethereum Foundation, jointly released a proposal ZK API Usage Credits in February 2026, aiming to use zero-knowledge proof to implement anonymous calls to large AI models. The logic of the plan is also very clear:

The user deposits a fund (such as 100 USDC) into the smart contract, and the contract records the deposit in the on-chain encrypted list. Every time the AI ​​API is called thereafter, the user does not need to reveal his identity. He only needs to generate a zero-knowledge proof to prove "I have the right to use this quota" to complete the call.

What does this plan require? It is a public bulletin board, a publicly verifiable and non-tamperable data layer used to record "who has how much quota" but not "who is who".

At the same time, the popularity of AI Agents has brought about another new question, that is, how can these automatically running programs complete economic cooperation with each other? After all, when an AI Agent needs to call the services of another AI Agent, it has to pay, establish credibility, 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 of AI Agents, provides a natural answer. Agents can initiate transactions on the chain, pledge deposits, and establish verifiable reputation records, all of which are based on the transparent data layer provided by the "bulletin board".

In the larger framework, the relationship between Ethereum and AI is even integrated - as AI becomes more capable, the requirements for privacy protection, verifiability and decentralization become more rigid.

So, Ethereum does not want to compete with AI, but to become the piece of infrastructure most needed in the AI era, a public data layer that anyone can write to, anyone can trust, and no one can turn off.

3. Is the narrative of “smart contracts” not enough?

Perhaps in Vitalik Buterin's vision, most of the future Ethereum users may not be "people", but AI Agents.

So this positioning from "World Computer" to "Bulletin Board" can easily be misinterpreted as lowering expectations, but in fact this understanding is the opposite.

"World Computer" is a narrative from an internal perspective, asking "what can our technology do", while "Bulletin Board" is a perspective from external needs, asking "what the world really needs."

This may also benefit from the group of people Vitalik met at cryptography conferences, those voting system researchers, certificate protocol designers, and privacy tool developers. They have no interest in blockchain and Ethereum, but what they need, Ethereum can provide.

Therefore, the author feels that Ethereum is indeed becoming more realistic step by step, because this is what a mature technology should look like. It no longer tries to define application scenarios, but polishes itself into a sufficiently reliable infrastructure, waiting for the scenarios that really 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 may not be a case of Ethereum's "doing something you can't do, but seeking for yourself".

After all, the core and most irreplaceable value of the blockchain is always the truth that is not subject to anyone’s will. That means that no matter how fast AI evolves, no matter how blurred the boundaries between reality and illusion are, as long as this bulletin board remains, humans will have a place where the "truth" can be stored.

This may be the most honest self-positioning of Ethereum.