Dialogue with the EAS Team: How does Ethereum withstand the identity authentication crisis brought by artificial intelligence?

Original Video: Bankless: Ethereum's Defense Against AI

Interview: Ryan Adams & David Hoffman, Bankless

Guests: Bryce Patrick & Steve Dakh, EAS

Compilation: bayemon.eth, ChainCatcher

EAS (Ethereum Attestation Service) was one of the four projects that made it to the finals of the Ethereum conference EDCON 2023 Super Demo this May. Although this project is not widely known, its innovative thinking about the foundational layer of Ethereum identity represents a significant breakthrough in on-chain identity proof. EthStorage, which also made it to the finals, completed a $7 million seed round financing at a valuation of $100 million by the end of July this year, so we believe EAS is an Alpha project worth paying attention to.

In the coming years, it is estimated that 99% of content generation work may be replaced by artificial intelligence. To ensure reliable identity verification in the age of AI, some teams have begun to consider hashing historical content, timestamping it, and storing it on the blockchain. This article will explore the Ethereum Attestation Service (EAS), a new public good that is open-source, permissionless, token-free, and available for free use.

In simple terms, current DID applications are still very closed and lack interoperability. EAS aims to build a foundational layer beneath the application layer to ensure the integrity and reliability of on-chain identities through a collection of multi-dimensional proofs. Without a foundational layer for constructing proofs, all DIDs become more limited. Furthermore, the existence of a foundational layer can bring more than just financial transactions and transfers into the crypto space.

Recently, Bankless invited EAS team builders Bryce Patrick and Steve Dakh to focus on discussing the Ethereum proof service EAS. ChainCatcher has compiled and organized this episode.

In today's discussion, we will explore the key to unlocking decentralized identity and non-financial uses of crypto, and we will gain key insights into the following four questions:

First, why decentralized identity is not mysterious, and how decentralized identity is merely a collection of attestations;

Second, why social networks, including Web2 and Twitter, are essentially just storage places for proofs;

Third, why financial use cases will rapidly develop after the power of proofs is unlocked;

Fourth, we will finally discuss topics related to decentralized identity, including Worldcoin, privacy, soulbound tokens, and a series of other themes.

Bankless: I believe this will be an educational program for everyone, as the entire Bankless community considers "identity" to be very important. There are often voices in the community saying, "We must first solve the currency problem, and then the identity problem; this seems to be the ultimate destination of the crypto world." Additionally, at Ethereum's Waterloo event, we heard many suggestions that we must communicate with the EAS team, as they have done many remarkable things in this field, representing a significant breakthrough in on-chain identity proof. "Open-source, no tokens, free, public goods," these characteristics of EAS are extremely appealing to Bankless. Bankless hopes that by the end of this episode, we will all have a deeper understanding of EAS and be able to view and predict the future development direction of "identity" from the perspective of "public goods."

Bankless: What does "Attestation" in Ethereum proof services mean, and how is it related to identity?

EAS: In simple terms, the Ethereum proof service is a signed proof made by an entity regarding something. With the addition of EAS, participants can prove anything.

We have always been very interested in solving the problems of decentralized identity and reputation, but we also know that this is a very difficult problem to solve because identity is relative, reputation is also relative, and exists in specific contexts. For example, my reputation is different in the eyes of Bryce and David. Identity is a very abstract and complex concept, and no one can truly achieve "complete" identity proof. At the same time, most current projects have fallen into the trap of identity proof, failing to describe the complex concept of "identity" through primitive forms. So when we began to think about the essence of identity proof and compared it to all existing identity proof platforms today, we found that most platforms capable of identity verification are almost all KYC companies. They have built closed identity verification platforms, and for other companies and developers that have to use this platform, once registered, all information is locked within it.

For example, Polygon ID essentially tests whether KYC can only be used internally within that platform. If other platforms want to use KYC verification, they must require smart contracts to perform similar verification procedures on each identity platform, which is meaningless for decentralization because it lacks interoperability, meaning these solutions do not actually solve the identity problem.

So we have to start thinking, what exactly is identity?

When I was born, my mother named me Steve, which can be seen as her proof of my name; then I went to school, and my teacher proved my grades, while the kids in the class might also attest to whether they liked me; the government can attest to my passport and driver's license; universities can attest to my degree; employers can attest to my employment status and can also declare whether I am a good employee. Thus, we quickly realize that identity and reputation can be represented as the sum of proofs about a person.

Not all identity protocols are heading in the wrong direction; it's just that there is currently no foundational layer in the Web3 world, and each project only represents one aspect of identity. Therefore, if we want to truly address the root of the identity proof problem, we need a foundational layer that allows any entity to make statements about anything, a common language and framework.

Bankless: While your definition of primitive is merely a statement made by someone about something, in fact, this primitive's "articulation" of identity is extremely profound. Therefore, when we discuss identity and primitives, many listeners (especially those new to the crypto world) may feel confused by the grand expressions and ways of thinking, regarding identity proof and primitive expression. Please explain more simply how identity is formed and how EAS as a primitive constitutes the underlying foundation of identity proof.

EAS: If we completely set aside the blockchain and only consider our interactions and engagements in the visible world. For example, if I borrow $5,000 from Ryan, he might write a promissory note, and our interaction is based on mutual trust. But if David wants to borrow from a bank, he needs to provide all documents to prove his ability to repay. This is because there is no trust between David and the bank, and he must comply with the relevant regulations for bank lending. But regardless of the trust basis, the key to identity proof is that all entities are merely making proofs about each other. So the way proofs work can be summarized as any interaction attempting to establish trust while ensuring the other party has certain reputational support.

Bankless: Does EAS only focus on identity verification, or does it have broader application scenarios and goals?

EAS: The use of proofs goes far beyond identity; we first discuss identity because we like to reveal complex concepts through simple explanations. In fact, proofs can be used in supply chains, voting, certification, ticketing, and various other matters not directly related to identity. In real life, these actions are things we do daily, but there has yet to be a fully digitalized, structured, and standardized method to complete the proof of these transactions. This is the magic of EAS; it can create a template (Schema) that describes the content and process of proofs and, based on this, prove various social activities. We believe this is the true revolution that EAS can bring.

Take notarization services as an example; if you want to sign a mortgage document or some important document, you usually need a notary present, and the notary itself is a proof of the document. However, for the blockchain, we do not have a product that can structure the role of the "notary." While current digital signatures and verification timestamps can support the authenticity of proofs, we still lack a more combinatorial and interoperable way to structure them to meet the needs of more people.

Bankless: So to summarize, the concept of proof is essentially the interactions that some people have on-chain with others, or unilateral claims made? For example, I own rsa.eth, corresponding to an Ethereum address, and I can perform operations like signing and digital verification on-chain. When the system prompts me to sign, my choice is essentially "proving" that these operations exist.

EAS: Yes, it is structured according to EAS standards, but each proof is signed with the wallet's private key, so it can clearly point to the entity making the statement. For example, in today's social media, posting is also a form of proof; if David likes a comment, that is also a proof of "liking this post." The problem still lies in the fact that we do not have a core foundational layer that connects social activities with proofs. Additionally, beyond on-chain proofs, EAS will also ensure that proofs remain accessible off-chain in a specific manner, making EAS a type of off-chain protocol for digital signatures.

Bankless: The primitive indeed requires people to think about "what is proof" in a whole new way. So can it be understood that my identity is the statements made about me by those I interact with, through my social environment?

EAS: Identity not only stems from statements but is more importantly shaped by the evaluations of those entities making those statements. For example, if I show you a statement from Vitalik claiming I am a good person, someone who knows Vitalik or has a favorable view of Ethereum might find that very valuable, while someone who only uses Solana might not. So, this method of proof is actually very valid; if I want to borrow from a certain entity, I need to show that entity relevant proofs that may meet its requirements, while for other entities, additional supporting materials may be needed.

In a sense, this characteristic brings unprecedented decentralization to EAS—how the world perceives a person depends on the proof subject, but the importance placed on the proof also varies from person to person. I believe this is the only way to solve the problem of decentralized identity, which is that you cannot pre-assume what identity is; it can be composed of many factors. Perhaps I have a proof that I was once a member of the Mickey Mouse Club, but the importance of that proof varies in the eyes of different people.

Bankless: In fact, there have been many attempts at identity in the early days of Bitcoin, as people already realized the relationship between private keys and identity. Subsequently, projects like WorldCoin and Crypto Meta began to seek solutions for identity proof at the application layer. Previously, you mentioned that these attempts at identity cannot fully solve the problem at the application layer, which is why a foundational module needs to be built. Can you explain in detail why a foundational module is necessary to build more applications on top of it?

EAS: As I mentioned earlier, all identity solutions are heading in the right direction. For WorldCoin, some people are concerned about iris scanning, while others are indifferent. However, the iris is just one part of a person's identity. If solutions like Worldcoin and Bright ID are fighting their own battles, they cannot give developers and users the opportunity to choose "whether to trust." Therefore, while we believe all identity solutions are heading in the right direction, they often either issue tokens or extract value at the protocol layer. Considering trust and identity in this context is a bit like oil and water; people cannot truly discuss finance, trust, and identity simultaneously. But if we truly have a reliable neutral foundational layer where any entity can make various types of proofs, then Worldcoin and other protocols can actually become more composable.

Moreover, for these companies, without a foundational primitive model, different identity proof solutions must make various assumptions about identity. I believe this is the biggest failure of companies like uPort—they made too many assumptions about "what is identity" and relied heavily on these standards. But as mentioned earlier, a person's identity is a very complex collection of proofs, so these assumptions are not universally applicable. EAS is different; uPort can preset a template they want to build and test it, but they are still on the same layer, and any smart contract can achieve template reuse. This is why EAS makes proofs more interoperable and more conducive to building decentralized identity and reputation systems.

Bankless: What form does EAS specifically take? Is it a standard similar to ERC?

EAS: The basic composition of EAS includes two parts represented in the form of smart contracts: a schema registry and a proof ledger. The schema registry allows anyone to register any type of statement, while the proof ledger is used to store proofs, with each proof referencing a specific schema to describe the data structure and content of the proof. Additionally, EAS supports off-chain statement protocols, allowing statements to be generated and transmitted off-chain without incurring transaction fees, and can later be timestamped or revoked. These off-chain statements also have complete portability, allowing them to be transferred from one party to another and uploaded to a server for verification when needed.

One key point is that these proofs do not necessarily require a recipient because EAS can also serve as self-attestation for individuals. For example, if Bankless wants to prove the authenticity of this episode, they can generate a hash of this episode and prove that Bankless indeed generated this hash, but this does not necessarily involve other subjects. The key is that this known entity is signing a piece of structured data at a certain point in time.

I believe in the context of Web3, that is, in terms of crypto-native technology, the reason we want to record certain content on-chain is to enable smart contracts to interact with it. Perhaps especially in decentralized communities, we may want to make community governance more transparent, such as how funds are allocated. In such a highly decentralized world, it makes more sense to put more content on-chain. However, there are also many conventional offline use cases that only require proof of signature authenticity, so it really depends on the goals of the use case, and they all have value.

Bankless: This also means that because EAS is open-source, anyone can propose any schema they want, as long as they can organize enough people to participate and reach a consensus, they can adopt some standard to prove whether an individual has a degree from their institution, using this degree for on-chain proof, and adopt some self-created standard on top of EAS.

EAS: You're right, because I think one challenge faced by previous attempts to create some degree schema is that people made too many assumptions about the fields required in the schema. In reality, we just need to allow the community to collaboratively develop the correct schema. Over time, we have seen a lot of research done on issues like the best charging ports for electric vehicles, and then Tesla stated that they would actually build their own standard rather than adopt existing ones. You really need to focus on the issues that matter to users and let standards develop over time.

Bankless: EAS gives me the feeling of going back to the first time I learned about HTTP, because it is so flexible and seems to accomplish many things at once, with capabilities that seem limitless. For EAS, they are the primitive building blocks of reputation and identity, the cornerstone of organizing the operation of social identity proof. And "proof" can accomplish anything like HTTP; are you worried that we are developing a "big and unwieldy" functionality?

EAS: I don't think EAS is "big and unwieldy." This is a characteristic of these technologies; new technologies can achieve things that were previously impossible, so there are infinite possibilities. Interestingly, it does not necessarily require large-scale network effects to operate. For example, if an entity decides to start using EAS to prove tickets for entities that have tickets, it only requires consensus on the proof between that entity and its customers. For many use cases, it is not necessary to have a large number of people sign up to use EAS for identity proof.

We have been hosting hackathons in recent months. In a recent competition, 25 teams developed based on EAS. It is interesting to see people building a variety of applications, some related to medicine, some involving cross-chain payment systems, and some related to certification of open-source software, etc. There are simply too many use cases, and people can integrate them into their applications in some way; otherwise, they would have to build some smart contracts and test them within their own platforms. Putting all applications that use EAS in a standardized place will make these proofs more valuable.

What we are really trying to do is lean towards an ecosystem narrative, so even as a foundational layer for building identity, EAS is not a simple identity protocol. What we want to do is help the identity ecosystem connect more closely, bringing together developers from different fields, who naturally create any schema about identity proof and the convenience of signing digital signatures. When such a universal solution appears in the ecosystem, the entire system will follow.

Bankless: One refreshing aspect of EAS is that the team has no tokens, no venture capital, and does not offer incentives like other companies. Can you briefly explain EAS's growth vision and whether there are plans for global expansion?

EAS: Of course, our goal is to create a foundational layer infrastructure for anyone, rather than owning all the information about users. We hope to bring positive change to the world by creating this infrastructure, making all certifications more valuable. You believe that building more trust in the digital world is very important, whether on-chain or off-line, because the current online experience is filled with distrust, misinformation, fraud, and scams. We believe that by using digital signatures and building a trust network for certifications, we can help people engage more safely online while encouraging more decentralized activities, which is very important. Without these trust mechanisms, we will face increasing challenges in the face of rising fraud and misinformation. Therefore, through certification, we can build trust better.

Bankless: Why do we need certification in this digital age, what will EAS bring to our future world, and will EAS drive the next transformation of human society like the internet?

EAS: With the rise of AI-generated content, proving the authenticity of our online consumption and interactions will become increasingly difficult. While we can prove the authenticity of a document through digital signatures, it is challenging to verify whether a person in an audio file is an AI imitation. However, if we use EAS, we believe that we can establish a complete chain of evidence solely based on digital signatures and verified timestamps.

I like to give an example: imagine that 99% of video content is genuinely recorded rather than AI-generated, but in the coming years, there could be a dramatic shift. EAS enables people to store any type of content on-chain and confirm its authenticity. Therefore, we can simply take some historical content, hash it, and store it on-chain with a timestamp as proof, so that a thousand years later, the proof we stored can reveal that this content actually existed before we had AI replication technology. Thus, we can preserve historical proof in this way, which I think is very important because the emergence of AI poses significant challenges to the preservation and authenticity verification of historical documents. Imagine in the coming years, you might receive a FaceTime video call with a family member's image on the screen, but in fact, it is an AI imitation; recognizing the authenticity of the person on the screen will become increasingly difficult. Therefore, over time, digital signatures will become more important, helping to prevent potential fraud and maintain the authenticity of content.

EAS is entirely based on EVM (Ethereum Virtual Machine), and one important aspect needs to be completed on-chain. Although technically it does not have to be this way, having a schema registry on-chain allows for immediate understanding of its content whenever a confirmation occurs, whether on-chain or off-chain, which I think is very important.

In general, offline confirmations will not be stored, so technically it does not necessarily need to be based on Ethereum. However, because it is signed using Ethereum wallets, it can only work when signed with Ethereum wallets, using EIP712 for signing offline confirmations, which can later be verified by smart contracts on-chain.

We chose Ethereum because we believe it is the most important blockchain infrastructure and the choice of the vast majority of developers. We also plan to launch on other EVMs, which may be Layer 2 solutions of Ethereum or Layer 2 solutions of other public chains that are still based on EVM.

Bankless: Ethereum and similar blockchain technologies are not just financial tools; they can serve as a broader global distributed infrastructure for establishing decentralized, unstoppable, and permissionless identity and confirmation systems. This is a potential use case that can provide public benefits and services far beyond finance.

In the current internet era, trust and identity verification are crucial, especially when facing issues like misinformation, fraud, and privacy violations. Ethereum and other blockchain technologies provide powerful tools for building these trust mechanisms. Whether in finance or other fields, distributed identity verification and confirmation can enhance users' online experiences, improve security, and reduce the spread of fraud and misinformation.

Moreover, this technology has a global nature, which can help complete these tasks in regions without stable financial or identity verification systems, supporting public benefits and human rights worldwide. Therefore, Ethereum and similar technologies indeed have the potential to become global public infrastructure, bringing positive impacts to global society, not just limited to finance. This potential impact may be broader and more significant than applications in the financial sector.

EAS: I think this is a very important point. In recent years, the blockchain and cryptocurrency space has indeed mainly focused on decentralization in assets and finance. This includes cryptocurrencies, decentralized finance (DeFi) applications, and asset management, among others. The development of these areas is very important, but there are many other non-financial issues and applications that can be addressed through decentralized technology.

Decentralized identity verification and confirmation is one very critical area because it applies not only to finance but to almost all other fields. For example, decentralized identity verification can be used for medical records, degree certification, digital rights management, supply chain traceability, voting systems, and so on. These areas can benefit from decentralized, verifiable identity and confirmation systems to enhance transparency, reduce fraud risk, and promote innovation.

Due to the universality and security of blockchain technology, it can become a powerful tool for solving various real-world problems. Therefore, developing decentralized identity verification and confirmation systems is an important direction that can bring more benefits to society, not just limited to finance. This also aligns with Ethereum's original vision of creating a decentralized global computing platform capable of handling various different applications and use cases.

This is a very important point. As more and more people possess private keys and use crypto technologies like NFTs, we are now in a good position for entities to begin entering the identity verification space. You mentioned that Ethereum's original vision was to decentralize everything, but despite significant progress in finance over the past few years, many unresolved issues still exist.

These unresolved issues include identity verification, degree certification, digital rights management, supply chain traceability, and more. Previously, building applications related to these on Ethereum required developers to write smart contracts, which raised the barrier to entry in these fields. But now, with the emergence of EAS, anyone, including institutions, can use no-code or low-code tools to create custom identity verification solutions, thereby lowering the barrier to entry.

This universality and ease of use make EAS a powerful tool for solving various real-world problems. It is not limited to finance but applies to almost all fields. This trend will help realize Ethereum's original vision of creating a global computing platform capable of handling various different applications and use cases. It provides institutions and individuals with a more open and innovative way to handle identity verification and confirmation, bringing more benefits to society.

Bankless: A hallmark of a new technology being put to use is that there are already crypto projects integrating EAS for identity verification. Can you briefly introduce the projects currently using EAS to solve problems?

EAS: An important example is Optimism. Optimism is one of Ethereum's Layer 2 scaling solutions, aimed at improving Ethereum's performance and scalability. Optimism has chosen to adopt EAS as its core infrastructure for various confirmation and identity verification operations. They have already integrated EAS into their local codebase, allowing any new chain deployed on Optimism to automatically inherit EAS contracts. Optimism is committed to advancing the field of confirmation and identity verification and sees EAS as a key piece of infrastructure to achieve this goal.

Additionally, EAS has collaborated with many other identity verification protocols and projects and has received positive feedback. Due to EAS's universality and flexibility, it can adapt to various different application scenarios and provide developers with powerful tools to build identity verification and confirmation solutions.

These collaborations and integrations indicate that EAS is gradually becoming one of the standards in the blockchain space, promising to bring more innovation and development to the field of identity verification and confirmation.

Yes, establishing a standard and ensuring its widespread adoption is a challenging task. You mentioned the concern during the early development of EAS about becoming another attempt to establish a standard, which is a valid concern. However, EAS has achieved significant success in becoming a core infrastructure for identity verification and confirmation. The collaboration with Optimism and its decision to incorporate EAS into its core infrastructure is a major victory that helps ensure the use of the same standard across the ecosystem, rather than fragmenting into multiple standards.

By establishing partnerships with other identity verification protocols and gaining their support, EAS has earned broad acceptance and backing, indicating that EAS is likely to become a universal, widely adopted standard that addresses the key issues of identity verification and confirmation, rather than merely attempting to monopolize the market. This collaboration and openness are expected to enable EAS to play an important role in a wide range of application areas, thereby enhancing the credibility and security of the entire Web3 ecosystem.

The smart contracts of EAS have become part of every chain deployed on the OP Stack. This indicates that EAS's standards will become a core component of the OP Stack ecosystem, rather than just an independent project. This integration is expected to provide identity verification and confirmation capabilities for various applications on OP Stack chains, thereby offering greater credibility and security for a wide range of use cases and users.

Currently, the attestations used in Optimism cover multiple use cases, including the following aspects:

1. Proof of Governance Roles Attestations: Some projects are attempting to prove different governance roles within DAOs for identity verification in governance decisions.

2. Proof of Optimism Domain Names: Some projects are proving different aspects of Optimism's domain names and domain registration to enhance the credibility and identity verification of domain names.

3. Quadratic Voting: EAS is used for quadratic voting; for example, in a hackathon, all teams can use EAS for quadratic voting, and anyone can aggregate and verify the ballots to determine who will receive rewards.

4. Gitcoin Passport Stamps: The Gitcoin Passport Stamps program is migrating to use attestations as basic building blocks to make it more composable and better integrate with other identity solutions.

Bankless: Recently, blockchain applications related to "identity" seem to be Friend.tech, which requires Twitter authentication to confirm identity authenticity. This authentication is valid, but technically, since Twitter has access to all identity information, this authentication is not perfect.

EAS: Yes, for the blockchain, this could lead to keys being controlled by third parties, thus eliminating the need for any other authentication authority. At the same time, this method of authentication does not involve any interoperability; if only one API is used, it is difficult to ensure it remains updated and that the project team does not arbitrarily change the code. Therefore, Friend.tech essentially revolves around a very unique use case centered on Web2 social interactions, still following the old path of Web2 social verification, just transferring the social graph to some extent onto the chain. In short, we still need a way to make people's identity verification more interoperable.

Bankless: I think this truly illustrates the need for an application layer on top of EAS. Once the number of proofs increases exponentially, we will need institutions like proof service providers to help re-integrate the 10,000 different proofs created daily. As we discussed earlier, there are various attempts at identity verification, with everyone trying to validate identity in the Web3 world. I think this business model has now been established, which is that we cannot directly do identity verification; it must form naturally. Once there are enough proofs, we will need an application layer to help us provide a lens to view all these proofs.

EAS: Imagine a future where everyone can view relevant certifications of their trading partners. For example, the relationship this entity had with me, whether friends have certified their authenticity.

In the near future, trust networks will become more visualized, and by wearing devices like Vision Pro, one can start browsing different trust networks. But the difference is that in today's real world, we are assigned a trust score, like the credit score involved in bank assessments. In the future world, we will be able to customize the weight of trusted levels, corresponding to what we initially said about "everyone's perception of the importance of certification varies."

Imagine when a person begins to establish a brand new decentralized trust network, everyone's trust score in the network starts from zero, and they all have the right to set their scoring weights. For example, because I trust my mom and good friends very much, I might set a high weight for a person's proof because they have confirmed it. Applications like MetaMask might display everyone's credit scores on the page, allowing users to form their unique trust networks.

This is a huge issue, and we are working with some different teams that typically look at on-chain data from various DeFi platforms, aggregate it, and propose various scores. But now, if everyone starts doing various certifications, you can begin to define various scores, connections, and various categories of metrics. For example, what is the individual's DeFi score? What is their social score? What are their other scores? There will be countless scoring categories. Therefore, being able to integrate all this data and understand it will become very important for providers, and open-source tools that allow users to run and integrate proofs and generate scores will also be interesting. This way, you can have other entities provide proof for this entity's score.

So in the example I gave you earlier, for instance, being able to obtain relative trust from someone, perhaps that person is not in your network, so you can have other trusted entities, like companies such as Equifax in the world, which not only do credit scoring but also start integrating proof data and establish different views of entities based on that data.

Bankless: Privacy is also an important topic for Web3. Did EAS consider privacy protection issues during its construction, or does privacy need to be maintained through an additional application layer?

EAS: Generally, we tell people to be mindful of privacy issues when making on-chain proofs. If certain content is to be put on-chain, it should obviously not contain any private data. For example, if Coinbase wants to perform KYC verification for a certain address, Coinbase only needs to prove that this address passed the test without needing to prove who you are. Therefore, you can create a schema like "KYC Passed" and assign it a true value. Other entities can also use it, and services accepting these proofs can conduct due diligence; for example, they might trust Coinbase's proof or other entities' proofs and build it into their applications. This is also why we built off-chain proofs, because in the real world, IDs, passports, and driver's licenses are essentially proofs, but they are off-chain and not public; users only display them when necessary.

We have also created some tools that can prove a large amount of private data. For example, imagine a doctor's office can prove all medical records; we built a fantastic tool that can create all these records into a Merkle tree and prove the root hash on-chain. Then, anyone can prove a part of that tree to other entities; basically, I can prove to my insurance company that I indeed received treatment for which they provided insurance, and then only reveal part of the medical data for verification.

Additionally, there are zero-knowledge proofs that can prove private data without actually revealing that data. The issue with ZK is that so far, every solution has been very specific, and there is no universal "ZK everything" solution. Therefore, we do not have a clear view on which zero-knowledge proof system to use; there are many different options, and we do not preset the content of the proofs. Proofs can be a complete ZKP, or they can be the kind of privacy-protecting statements we show, whether off-chain or even a public tweet. In short, we focus on privacy and inform everyone in the documentation to be cautious about the content of the proofs, as on-chain proofs will exist forever.

We are also working with other developer teams to build privacy protection tools to help developers address these types of issues. For example, many teams at hackathons are trying to create ZKPs based on proof data using EAS, which means selectively sharing identity information. We have also received a lot of positive feedback on the aforementioned Merkle tree; for example, Sismo, integrated with EAS, can be used to create ZKPs, which means that as long as I have proof of a specific thing, I can indicate ownership without revealing its specific address. The combination of EAS and ZKP can achieve verification and information sharing while protecting privacy.

Bankless: How will EAS obtain funding without issuing tokens or having VCs?

EAS: EAS currently obtains funding through grants. The key issue we are focusing on is schema coordination, that is, as custom schemas gradually increase, how EAS can educate people on organizing and choosing the right schemas. Optimism has just provided us with a substantial grant to address this issue. Additionally, we are exploring new funding mechanisms, such as retrospective public goods funds. But so far, the operational funding for EAS mainly comes from self-funding and grants.

Bankless: What is the relationship between the concept of Soul Bound Tokens and EAS?

EAS: I remember Vitalik defined Soul Bound Tokens in 2020, and at that time, I thought it was a flawed solution. Due to the NFT craze at the time, everyone could integrate the viewing function of NFTs into their wallets, so when people considered what tools to use to solve identity or reputation issues, the first thing that came to mind was NFTs. But in reality, we believe NFTs are not suitable for identity proof. Is it necessary to redeploy a brand new contract inheriting the SBT interface to prove my trust in a person, and then write whether they are trustworthy in it? Each new SBT can belong to different smart contracts, and everyone can design completely different smart contracts with entirely different interfaces and non-interoperable functions. Therefore, if I want to check whether their address has updated identity information, it is impossible to obtain it easily.

EAS, as a primitive, can provide a consistent interface and proof examples. This is more meaningful for enhancing the universality of proofs.