Proof of Humanity (PoH) attestation vs SBT-based attestation

Proof of Humanity (PoH) excels at establishing a strong, Sybil-resistant link between a single wallet and a verified human identity. It achieves this through a social consensus model where users submit video verifications that are challenged by the community. This results in a high-trust, binary attestation (you are either a verified human or not), as evidenced by its use as a foundational layer for Universal Basic Income (UBI) distributions and governance systems like Kleros. The on-chain registry of over 20,000 verified profiles demonstrates its operational scale and resistance to automated attacks.

SBT-based attestation takes a different approach by using non-transferable tokens (Soulbound Tokens) as a flexible, composable primitive for any credential. This strategy, championed by Ethereum's ERC-721 & ERC-1155 standards and networks like Polygon, results in a trade-off: while potentially less Sybil-resistant at the base layer, it enables granular, programmable identity. A single "soul" (wallet) can hold SBTs for Gitcoin Passport scores, Guild.xyz memberships, and academic credentials, creating a rich, multi-dimensional identity graph that applications can query and build upon.

The key trade-off: If your priority is maximizing Sybil resistance for a core, binary human check (e.g., for fair airdrops or governance), choose Proof of Humanity. Its curated registry provides a high-confidence signal. If you prioritize flexibility, programmability, and composing a rich identity graph from multiple sources, choose SBT-based attestation. Its ecosystem of issuers and standards like Verifiable Credentials (VCs) makes it ideal for complex reputation systems and access control.

Proof of Humanity (PoH) excels at establishing a Sybil-resistant, global, and singular human identity. Its rigorous, video-based verification process, which has registered over 20,000 unique humans, creates a strong, binary attestation of personhood. This is critical for protocols like Universal Basic Income (UBI) or quadratic funding platforms like Gitcoin Grants, where preventing duplicate identities is paramount for fair distribution. The system's reliance on a centralized registry and slow, manual verification (taking days) is the trade-off for this high-assurance, one-human-one-ID guarantee.

Soulbound Token (SBT)-based attestation takes a different approach by enabling a decentralized, composable, and multi-faceted identity graph. Instead of one central truth, SBTs allow entities like Ethereum Attestation Service (EAS), Gitcoin Passport, or Orange Protocol to issue portable credentials for skills, affiliations, and reputations directly to a user's wallet. This results in a system with superior scalability and programmability, enabling complex, on-chain reputation systems. The trade-off is a weaker initial Sybil-resistance, as it often depends on the trustworthiness of the underlying attestors rather than a singular, cryptoeconomic proof of humanity.

The key trade-off: If your priority is maximizing Sybil-resistance for a global, permissionless system where a single, unforgeable human identity is the core asset, choose Proof of Humanity. If you prioritize scalable, flexible, and composable reputation that can integrate credentials from multiple sources (e.g., World ID, BrightID, academic degrees) to build a rich identity graph, choose SBT-based attestation. For most dApps building nuanced on-chain reputation—from lending with ArcX to governance with Optimism's AttestationStation—SBTs offer the necessary modularity.