Analysis of Polkadot's "Proof of Personhood" system design: A Sybil resistance solution without KYC

The Existence Problem of Web3: Real People or Robots?

Every day, millions of applications face a similar challenge: how to distinguish genuine users from automated scripts? In the crypto world, this problem becomes critically urgent due to real economic consequences:

Airdrops controlled by farming studios with thousands of wallets, governance manipulated through Sybil attacks, free services immediately exploited by operators with multiple accounts. If you rely on traditional solutions—mandatory KYC—you protect the system but sacrifice privacy, which conflicts with Web3’s foundational ideals.

Polkadot recognized this dilemma and proposed an alternative approach: instead of proving “who you are,” simply prove “you are an independent individual.” This is the core idea behind Proof of Personhood.

How is Proof of Personhood different from “identity” recognition?

To understand the power of this technology, first distinguish between two often-confused concepts:

Identity (Identity): A system assigns a unique identifier to you, tracking you across all platforms. Examples include passports or social security numbers—they create a “comprehensive profile” that can be reused anywhere.

Individuality (Individuality): Only confirms that you exist as an independent person, without linking your behavior across different services. You can use multiple aliases, but the system ensures they all belong to the same person.

As Gavin Wood—founder of Polkadot—describes: “Web2 solves the Sybil problem by sacrificing privacy. But with Web3, that’s unacceptable.”

Proof of Personhood uses zero-knowledge cryptography to verify identity without revealing personal information. Each application you join has a completely different alias, unlinked to others, yet the system affirms they all belong to “a single real person.”

Project Individuality: How Polkadot Implements This Technology

Project Individuality is Polkadot’s Proof of Personhood system, built on the Polkadot People Chain—a dedicated chain managed by Polkadot’s decentralized governance, not any company.

Instead of relying on a single verification method, the system employs multiple decentralized personal mechanisms (DIMs) to prove that a “real person” can only possess one identity. Gavin compares these mechanisms to a “personal game”—aiming to make it difficult or prohibitively expensive for someone to fake multiple identities.

DIM 1: Proof-of-Ink (PoI) — Ink Stamping Proof

The first mechanism requires users to tattoo a pattern generated randomly by the blockchain:

The system creates billions of unique geometric tattoo patterns. When registering, you receive 100 patterns exclusive to you. You select one, tattoo it on a fixed spot (on the face inside the left wrist), then submit a video of the tattooing process along with a photo confirmation.

PoI acts as a “bootstrap” for the system. The act of tattooing—a costly, irreversible action—helps filter out the first group of real individuals. These users become oracles on the chain, evaluating proofs from others. Gavin calls this the “crowd rule”—relying on many real individuals instead of centralized organizations.

DIM 2: Proof-of-Video-Interaction (PoVI) — Video Interaction Proof

The second mechanism lowers participation barriers, without requiring permanent tattooing:

Weekly, you spend about 5 minutes playing a small, silent game. You join a synchronized video call with 15 others worldwide. Continuous participation maintains your “personal score”; if you stop, the score gradually decreases.

PoVI relies on ongoing investment—making impersonation require sustained effort over time. Gavin admits that as AI-generated content advances, both PoI and PoVI could be faked within 2–5 years, but he also notes that hiring a real person for 5 minutes at $1 could still be cheaper than operating complex AI systems.

A third mechanism, currently under development, aims to “completely block AI,” but details are kept confidential.

The $3 Million Incentive Plan: How Polkadot Attracts Large-Scale User Participation

Proposal #1783 requests $3,009,600 to launch the “Polkadot Large-Scale User Acquisition Campaign.” This fund will be distributed via a predefined on-chain logic—completely automated, without intermediaries.

The incentive system is designed in three tiers:

Kickoff Rewards: Attract early users with different levels—earliest participants get $200, mid-term $100, later $50. The “early bird, late missed” approach encourages quick engagement.

Activity Rewards: Each week, you earn about $10 for maintaining activity and participating in governance on Polkadot. Gavin explains this mechanism isn’t a one-time pull but aims to “retain users long-term, not just snapshot once.”

Weekly Raffles: The majority of the budget—about 140 people weekly receive ~250 USD, with a monthly grand prize of $2,500. The system limits the frequency of wins—each person has less than a 1/10 chance—to prevent “continuous winners” and ensure fairness.

Gavin emphasizes: “Not a single dollar flows through intermediaries. Every USD is paid directly to users.”

This plan isn’t just a simple airdrop; it’s linked to core products: the Polkadot mobile app will integrate Project Individuality for quick user verification; Polkadot Hub enables fee-free transfers; the “New Deal” staking plan allows participation in network security via individuals without large capital.

Why Proof of Personhood Will Transform Web3

Strong personal proof will unlock many long-held Web3 scenarios:

Fair Airdrops: Currently, airdrops rely on transaction history or token holdings, favoring long-term holders or farming studios. With Proof of Personhood, projects can distribute tokens to independent individuals, building more genuine communities and avoiding professional farming teams “sweeping” the system.

Free Services Become Feasible: If you can distinguish 100 real users from one operator controlling 100 robot accounts, you can offer free services without fear of abuse. On Polkadot Hub, this means: truly free dApps, no gas fees, no hidden charges, experience akin to Web2.

New Governance Models: Confirming “one person, one independent individual” breaks the monopoly of token-based power. Polkadot can experiment with quadratic voting, one person one vote, or future governance models like FutaGov (future governance), adjusting voting rights based on performance.

Building Trustworthy Digital Societies: MMO games can give out free starter gifts while preventing mass account creation; social networks can develop reputation systems for real individuals; reward and matchmaking systems become fairer.

Gavin’s broader vision is “Agentic Society”—a trustworthy digital society where interactions come from truly independent individuals, not automated scripts or mass accounts.

Practical Challenges: Why Is the Community Divided?

Despite its potential, this proposal faces skepticism within the Polkadot DAO community:

Lack of Metrics: The plan lacks clear KPIs—how many will be verified? How long will they stay active? The Polkadot Mobile app, which promises to integrate Project Individuality, has not yet launched publicly, raising concerns about readiness.

AI Risks: Gavin points out that hiring real people is still cheaper than AI in the short term, but this advantage is shrinking. The “anti-AI” mechanism third under development has not been revealed; it’s uncertain if it can patch potential loopholes in time.

Economic Attacks: Concerns about “economic abuse”—for example, paying students $10 to verify, then earning higher rewards. In many regions, $250 is a significant income, which could lead to mass farming or verification groups, weakening system fairness.

Trade-off Between Usability and Security: The system must be easy for the masses to participate in but also resistant to Sybil attacks—very difficult to balance. Permanent tattooing deters many; periodic video interactions can be intrusive, especially in privacy-sensitive or low-bandwidth environments.

Controversy Over HOLLAR: The proposal suggests shifting funds into HOLLAR (stablecoin ecosystem), prompting some members to question the necessity of this move.

Conclusion: A Different Experimental Step

Proof of Personhood is fundamentally different from traditional KYC. While KYC proves “who you are,” PoP only proves “you are a unique person.” With Polkadot’s low-cost, high-security, highly interoperable infrastructure, this kind of large-scale experiment is very feasible.

Project Individuality is expected to launch in Q4/2025, with many new mechanisms emerging in 2026. Whether proposal #1783 passes or not, this marks the first serious attempt in Web3 to answer: how can millions of “real people” participate in blockchain while still protecting privacy?

The future internet may no longer require you to prove “who you are,” but only to prove: you are a real individual.