TL;DR

• We’ve developed new Sybil classification models specifically analyzing wallets’ onchain history on Base - available to Base ecosystem builders interested in identifying who is Sybil and who’s human on the network

• With our new Base offering, users can mint Stamps-based score and data on Base, builders can classify Sybils using the Base model, and the Ethereum Activity Stamp now counts Base transaction history

• Make your project Sybil-resistant with Human Passport: https://docs.passport.xyz/building-with-passport/introduction

Base is one of the most commonly used Ethereum Layer 2 (L2) chains. As the Base ecosystem grows, so does the urgency of defending it from Sybil attacks. Airdrops, governance, quadratic funding, and other community programs — all of these are vulnerable to bots and fake identities.

That’s where Human Passport (formerly Gitcoin Passport) comes in. We help projects verify users and stay Sybil-resistant, without compromising privacy or user experience.

This blog explains what Sybil resistance means for projects, why it matters on Base, and how Human Passport helps teams stay secure, using Stamps, Model-Based Detection, and cross-chain scoring. See real-world examples at the end.

Why Sybil Resistance Matters on Base (and every other chain)

Getting a ton of low-quality signups, but no user engagement? This is a common problem. Sybil attacks not only deplete reward pools but also distort community data, hijack governance, and drain resources meant for genuine users, bringing actual value to the ecosystem.

As Base-native projects grow in size, value, and user activity, they naturally become more attractive targets for Sybil farms and coordinated bot networks, many of which operate across multiple chains. From that perspective, Sybil resistance has to be part of the foundation every project considers for their TGE stage and beyond.

Having fought Sybils for over 3 years, we know the problem very well. That’s why we’re deepening Human Passport’s support for Base: building smarter detection models, simplifying integration, and giving developers the tools they need to protect their communities at scale.

Strengthening Sybil Resistance on Base with Human Passport

Base has quickly become a hub for onchain creativity and innovation. With daily active users (DAU) between 1-3 million and over 8 million daily transactions in recent months, totaling more than 2 billion transactions to date, it’s the fastest-growing Ethereum Layer 2 chain (source: Dune Analytics).

But with that rapid growth comes a challenge: how do you prove users are real, without forcing them through burdensome steps or compromising their privacy? The answer is to implement privacy-preserving Proof of Personhood and Sybil resistance. And that’s where Human Passport comes into play.

Human Passport helps projects solve the Sybil problem

https://x.com/HumnPassport/status/1885010318533026077

Human Passport assists projects in addressing the Sybil problem by providing a decentralized, privacy-preserving identity verification system. With over 2 million users, Human Passport offers a Sybil resistance protocol and identity aggregation dApp designed to verify unique user identities.

We aren’t new to Base: Human Passport already enables users to push their Unique Humanity Score, and Stamps onchain to Base, as well as several other EVM-compatible chains.

Now, we’re expanding that support with Model-Based Detection, enabling real-time wallet screening requiring no user action beyond the transaction history they’ve already completed on Base; all users need to do is connect their wallet.

Introducing Model-Based Detection on Base

Model-Based Detection adds a new behavioral layer to Human Passport-powered Sybil resistance on Base. Unlike static trust signals like Stamps, this approach uses machine learning to analyze historical wallet activity and detect patterns associated with Sybil behavior.

In plain terms: it looks at what a wallet does, not only what it has. This lets us detect Sybils even when wallets appear “normal” on the surface.

💡 Combined approach: Use the Base model score first, with the Passport’s Stamps product as a secondary verification method to offer strong Sybil resistance while minimizing user friction and offering strong participation. See tutorial.

The Base Model: Built for Base Behavior

Our Base-specific model was trained on a massive list of wallets operating within the Base L2 environment. It knows what typical user behavior looks like on Base and flags deviations from those patterns.

How does it work? Models evaluate wallet addresses’ onchain history, using features like activity patterns and usage consistency to assign a trust score between 0 and 100. The Model scoring can happen completely in the background without users knowing, enabling those who have a strong transaction history to automatically participate, and potentially offering those who don’t pass the initial check to utilize a different verification system. The Passport team does not, however, expose the specific criteria used by these models to help prevent Sybils and other bad actors from reverse-engineering and manipulating the scores  — after all, Sybils adapt fast.

The Base-native model is already available in our API, meaning any project using Human Passport can access this layer of intelligence when filtering wallets.

The Aggregate Model: Cross-Chain Sybil Detection

Base is growing fast, but it’s not an isolated island. Many wallets arriving on Base bring a history along with them. That’s why we’ve built the aggregate model, which combines scores from multiple chain-specific models that Human Passport supports.

One model. One score. One API.

Why check across multiple networks?

Because wallet behavior doesn’t stop at a single chain. Cross-chain analysis enables deeper context and more accurate detection:

• Airdrop hunters jumping between chains? Flagged.

• Multi-chain Sybils with clean Base history but dirty behavior on other networks? Caught.

• Good actors active on multiple chains but new to Base? Verified.

Models in action: LayerEdge Proof of Personhood

LayerEdge used Model-Based Detection as one of the 3 tools underpinning their Proof of Personhood campaign.

When users opted for Human Passport (by human.tech) in LayerEdge’s Proof of Humanity, our models analyzed their wallets’ onchain history in a short, privacy-preserving check.

Result? 116k unique wallets were checked against the Models API. No KYC. No Stamps. No hassle for users.

https://x.com/HumnPassport/status/1915147302685335832

The combined approach: Story Protocol’s $IP Airdrop

As mentioned earlier, the combined approach (aggregating both model scores and Stamps) offers the most robust Sybil resistance, and Story has made exceptionally good use of our toolkit.

When Story Protocol prepared for its token launch, it flipped the usual script: instead of chasing Sybils after the fact, it embedded identity infrastructure from the start.

Using Human Passport’s modular Sybil resistance stack, Story:

• Filtered bots early via Stamps during testnet

• Deployed machine learning and clustering models for large-scale risk classification

• Enabled borderline users to verify through Custom Passport dashboards

• Reallocated saved rewards to real users through validator staking

Result? $98M in an airdrop was protected in Story’s $IP case alone.

See the full Story Protocol case study for a deeper understanding of how you can use Human Passport to your advantage.

How to Get Started with Human Passport on Base

Human Passport’s integration is simple. Base projects can start scoring wallets immediately using our API. In general, we offer tools that meet teams where they are:

• Model Scores API: call our models directly to score wallets

• Stamp Scores: combine model detection with reputation Stamps

• Passport Embeds (coming soon): UI element to verify users directly on your website

Interested teams can visit the developer docs to explore technical integration, check Human Passport’s use cases, or reach out to us for tailored support!

📥 Send us a partnership request or sign up for early embed testing using our contact form.

We’re here to help Base projects grow safely and sustainably. Whether you’re running a token launch, building a dApp, or managing a community, Human Passport makes sure only real humans show up. We help build the human layer on Base.

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About Human Passport (formerly Gitcoin Passport)

Human Passport is an identity verification application and Sybil resistance protocol with more than 2M users. It enables users to collect verifiable credentials, or Stamps, that prove their identity and trustworthiness without exposing personally identifying information. To date, Human Passport has protected over $430M in airdrop and grant funds.

https://passport.human.tech

About human.tech

human.tech is a suite of technologies designed to enhance personal freedom, privacy, and financial autonomy. human.tech provides innovative solutions for secure identity, data ownership, and private transactions, ensuring that technology remains a tool for human empowerment.

https://human.tech