In the world of blockchain and decentralized technologies, the concept of proof of personhood has emerged as a crucial solution to combat issues like spam, concentration of power, and sybil attacks while ensuring privacy and avoiding dependence on centralized authorities. At its core, proof of personhood establishes a system that guarantees the unique identification of individual humans using cryptographic public keys. This article explores the significance of proof of personhood and its potential impact on various applications.
Key Advantages of Proof of Personhood
1. Decentralization: Proof of personhood empowers decentralized governance by preventing undue influence from wealthy actors. It levels the playing field, ensuring that decision-making processes remain democratic and not dictated by a select few.
2. Privacy Preservation: Unlike government-backed identity systems, which often compromise privacy by revealing extensive personal information, proof of personhood achieves verification without compromising sensitive data.
3. Anti-Spam Measures: By restricting bots and malicious actors, proof of personhood helps maintain the integrity of various applications, including social media posts, votes, and token distributions.
4. Affordable Access: Without proof of personhood, services may resort to pricing access high to deter attackers, but this can also exclude lower-income users. A robust proof-of-personhood system enables fair access for legitimate users while preventing abuse.
Early Attempts at Proof of Personhood
Several approaches to proof of personhood have emerged, with two prominent methodologies being social-graph-based and biometric verification.
1. Social-Graph-Based: In this method, existing verified users vouch for new ones, creating a network of trust. This approach is employed by projects like Proof of Humanity, where video verification and challenge mechanisms strengthen the verification process.
2. Biometric Verification: Biometric proof of personhood involves verifying unique physical or behavioral traits that distinguish humans from bots. Some projects combine both social-graph-based and biometric approaches to enhance the system’s reliability.
Promising Projects in the Proof of Personhood Space
Several projects have made strides in developing and implementing proof of personhood systems:
1. Proof of Humanity: This project employs video verification and vouching by existing users to establish the uniqueness of human identities.
2. BrightID: Users participate in video call “verification parties” where mutual verification takes place, and higher levels of verification can be achieved via vouching.
3. Idena: Participants undergo a captcha game at a specific time, followed by mutual verification to validate human identities.
4. Circles: Users are vouched for by existing members, and trust relationships are established within a graph, ensuring reliable identification from a personal perspective.
How does Worldcoin Approach Proof Of Personhood?
Worldcoin is a system that aims to verify unique human identities through iris scans and generate a “World ID” associated with a public key. Users install the Worldcoin app on their phones, which generates a private and public key. They then visit an “Orb” in-person, where their eyes are scanned and compared to existing records to ensure uniqueness. If successful, the Orb signs a message approving a specialized hash of the user’s iris scan, which is uploaded to a database. Users can later prove their uniqueness using ZK-SNARK without revealing their private key.
However, there are major issues with Worldcoin’s construction:
1. Privacy Concerns: The registry of iris scans raises privacy concerns, as it may reveal sensitive information. Additionally, scanning someone’s iris could potentially reveal more data than intended.
2. Accessibility Challenges: The system’s reliance on physical Orbs may hinder widespread accessibility. To be reliable, there needs to be a large number of Orbs worldwide, which may not be practical.
3. Centralization Risks: Although the software layer may be decentralized, the hardware nature of the Orb creates centralization risks. The Worldcoin Foundation could potentially insert backdoors, compromising the integrity of the system.
4. Security Vulnerabilities: Users’ phones could be hacked, leading to unauthorized access to their World ID. Coercion or manipulation might also occur during the iris scan process, and 3D-printing technology could potentially create fake identities.
Addressing these challenges will be crucial for Worldcoin to achieve its goals and ensure a secure and inclusive identity verification system.
What does Buterin think?
Vitalik suggests treating specialized-hardware biometrics, general-purpose biometrics, and social-graph-based systems as complementary techniques for creating a robust proof-of-personhood system. India’s Aadhaar is an example of the benefits of specialized-hardware biometrics, but it lacks decentralization. Social-graph-based systems can face tradeoffs between inclusivity and vulnerability. The ideal solution may involve a hybrid approach, combining the strengths of all three techniques.
Vitalik emphasizes the importance of vigilance and pushing for transparency, open-source technology, third-party audits, and checks and balances to ensure the system’s integrity. While challenges exist, the concept of proof-of-personhood is valuable, and the existing implementations have shown a commitment to privacy. The road ahead may be challenging, but progress in all types of proof-of-personhood is essential to create a more inclusive and decentralized world.
