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What is Proof of Humanity Protocol

Proof of Humanity is a system that combines a social verification web of trust with a video submission process to create a blockchain-based registry of unique humans, aimed at solving the sybil resistance problem.

What is Proof of Humanity Protocol - Hashtag Web3 article cover

In a digital world where one person can easily create thousands of fake accounts, how can we build systems that guarantee "one person, one vote" or a fair distribution of resources? This is known as the "sybil attack" problem, and it's one of the most difficult challenges in decentralized systems. Proof of Humanity (PoH) is an experimental social identity verification system on the Ethereum blockchain that aims to solve this problem.

PoH is a protocol that combines a web of trust, video verification, and token-curated registries to create a single, canonical list of unique, verified humans. The goal is to create a sybil-resistant identity that can be used by other applications, such as DAOs, for fair governance or for distributing a Universal Basic Income (UBI).

How Does Proof of Humanity Work?

The process for getting registered on the Proof of Humanity list is a unique blend of social and technical steps:

  1. The Profile: A user who wants to be registered must create a profile. This includes submitting a short video of themselves saying a specific phrase.
  2. The Deposit: To submit their profile, the user must pay a deposit in ETH. This deposit acts as a bond to discourage spam and low-quality submissions.
  3. Vouching (The Web of Trust): The user's profile cannot be submitted on its own. It must be "vouched for" by another, already registered human on the list. This creates a "web of trust," where existing members vouch for the humanity of new applicants.
  4. The Challenge Period: Once a profile is submitted, it enters a challenge period. During this time, anyone can "challenge" the registration if they believe it is a duplicate, a fake, a bot, or doesn't meet the submission guidelines.
    • To challenge, a user must also put up a deposit.
    • This initiates a dispute resolution process, where the case is sent to a decentralized court (like Kleros) for a decision.
    • If the challenger wins, they receive the submitter's deposit. If the submitter wins, they receive the challenger's deposit.
  5. Registration: If no challenge is made, or if the user wins any challenges, their profile is accepted and they are officially added to the "Proof of Humanity" registry. Their Ethereum address is now linked to a verified, unique human identity.

Use Cases for Proof of Humanity

A reliable list of unique humans unlocks a host of powerful new applications:

  • DAO Governance: DAOs can use PoH to implement a "one person, one vote" governance system, instead of the standard "one token, one vote" model which can lead to plutocracy.
  • Universal Basic Income (UBI): The UBI project, built on top of PoH, periodically distributes a basic income token to every single registered human on the list. This is only possible because the list is sybil-resistant.
  • Airdrop and Fair Distribution: New projects could use the PoH registry to airdrop their tokens, ensuring a fair distribution to real, unique individuals.
  • Credit and Reputation: A PoH identity could be the foundation for a Web3 reputation system, allowing for undercollateralized loans and other identity-based financial services.

Challenges and Criticisms

  • Privacy: The public nature of the registry, including the video submissions, raises significant privacy concerns for many users.
  • Accessibility: The process can be complex, and the ETH deposit required can be a barrier for some users.
  • Subjectivity: The social vouching and challenge process can be subjective and lead to disputes.

Proof of Humanity is a bold and fascinating experiment in decentralized identity. It's an attempt to solve one of the hardest problems in the space—sybil resistance—by creating a system that is part social network, part decentralized court, and part economic game. While it is not without its challenges, it offers a glimpse into a future where our digital identities are not just self-sovereign, but also verifiably human.


Frequently Asked Questions

1. What is the main purpose of Proof of Humanity?

The main purpose is to create a sybil-resistant list of unique humans on the blockchain. This helps to solve the "one person, one identity" problem, which is crucial for applications like fair voting and Universal Basic Income (UBI).

2. How does Proof of Humanity verify that someone is a unique human?

It uses a combination of methods: a video submission where the person speaks a specific phrase, a deposit of ETH to discourage spam, and a "web of trust" where existing registered members must vouch for new applicants.

3. What is a "sybil attack"?

A sybil attack is when a single person creates many fake accounts or identities to gain a disproportionate influence in a network. Proof of Humanity is designed to prevent this.

4. What is the UBI token?

The UBI token is the native token of the Universal Basic Income project, which is built on top of Proof of Humanity. It is periodically airdropped to every human registered on the PoH list.

5. What are the privacy concerns with Proof of Humanity?

The main privacy concern is that the registry, including the profile videos, is public on the blockchain. This means anyone can see who is on the list, which is a trade-off some users may not be comfortable with.

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