Blockchain Product Case Study: Why does Vitalik believe that Farcaster only needs to put account data on the chain to achieve decentralization?

Vitalik responded to the community's comments on the decentralized social protocol Farcaster on Twitter today, stating that although Farcaster only puts user identities on-chain, while most other data is stored through off-chain methods, it is already sufficient to prevent Sybil attacks and centralization interference. This classic case can be used to reflect on how blockchain technology should be integrated with products.

This article is compiled and translated. For any doubts, please refer to the original text.

Background: Introduction to Farcaster

Farcaster is a decentralized social protocol that provides users with a community protocol and frontend similar to Twitter, along with its innovative post interaction mode called Frame. Recently, it has attracted many users and is currently a social app highly favored by Vitalik.

Community Criticism: Farcaster Not Decentralized Enough

Community member Liron Shapira stated that although the Farcaster team claims to support blockchain technology, in reality, they only put the user registration part on-chain, which is essentially repeating what has been done with DNS and email addresses, with no significant improvement beyond that.

Currently, Farcaster merely copies Twitter's functions, provides subpar mini-games, and tools for market speculation gambling. Liron believes that 99% of the technology Farcaster is building is not blockchain-related.

Especially in terms of data storage, Farcaster does not use blockchain technology for information storage. Instead, it is stored in a P2P network node called Hub, similar to how many RSS readers act as "RSS hubs." This is why Liron thinks that promoting Farcaster as a blockchain use case is incorrect.

Recommended Read: What is the Federated Universe? How can Web3 accelerate the development of decentralized social protocols?
This article not only provides a quick introduction to the concept of decentralized social interactions but also clearly explains the key elements of decentralized community products such as usernames, data formats, data storage, and the differences in implementation among various competitors, offering a more structured view of the issues raised by Liron.

However, Liron also mentioned that Farcaster is an interesting experiment that provides more features for RSS and looks forward to observing whether it can bring new product traction to drive market growth.

Vitalik Believes On-Chain Accounts Are Sufficiently Decentralized

Vitalik stated that he has confirmed some information with the Farcaster team. He initially thought that Farcaster would store user post data in a big chain, similar to a simplified version of Filecoin, but later found out that this was not the case.

Farcaster stores data in a Hub, where each Hub stores the same data in a conflict-free replicated data type (CRDT) format and uses the sender's timestamp for sorting to ensure the final consistency of information. Vitalik believes that using this method can make scaling and expansion easier.

The only "blockchain" Farcaster uses is Ethereum, where user account data (Farcaster ID) is built on the Optimism mainnet. Vitalik stated that the utility of blockchain is not only for "storing" usernames but also for:

• Reducing spam: Fee design is important for reducing spam messages; otherwise, everyone will use it to back up other data.
• Not subject to centralized participant control: Blockchain nodes cannot delete, modify, or refuse access to user data at any time.
• Resistance to Sybil attacks: Registering usernames using blockchain is the only effective way to resist Sybil attacks. While it is technically possible to achieve this using Proof of Work (PoW), it is inefficient. Additionally, in practice, centralized participants have too many efficiency advantages over ordinary users on mobile phones or laptops.

Therefore, to meet Farcaster's goal of becoming a strong neutral network that does not rely on a single entity continuously, putting user data on-chain can play the most critical role.

Recommended Read: It's Not Just About Blockchain! How Stateless Infrastructure Can Bring Efficient Decentralized Networks
This article discusses that besides blockchain, there are many technologies such as DAGs, P2P networks, collectively referred to as stateless infrastructure, to achieve Web3 concepts like decentralization and free value transfer. It emphasizes the importance of using the right tools based on product needs.

Underlying Issue: When Is Blockchain Needed?

In fact, both parties' perspectives are not wrong; the crux lies in their different imaginations of decentralized community software. Vitalik believes that putting usernames on-chain already solves most problems, while Liron thinks that only putting usernames on-chain is meaningless, as it just expends more effort on things that email and RSS have already done well. Liron also believes that the issues raised by Vitalik can be addressed through other means.

The above dispute can be summarized as: when should blockchain be used? How to integrate decentralized community software ideally with blockchain is a question that needs continuous pondering.

Recommended Read: What is Global Consensus? Which products or features are suitable for building on Ethereum?
Recommended for its focus on "what requires strict global consensus," explaining what kind of products demand blockchain technology and reflecting the core of this dispute.

From a business and product perspective, the most crucial aspect is whether these discussions are meeting user needs. Whether users care about the decentralization behind account data or post data is essential. Additionally, while the narrative highlight is just one variable in determining whether Farcaster can ultimately attract more users, there are still many factors that need to be fully considered.