Attestation-Based Sybil Scores vs Token-Holding-Based Sybil Scores

Attestation-Based Sybil Scores excel at measuring real-world identity and social capital because they rely on verified credentials from trusted issuers like Ethereum Attestation Service (EAS) or Verax. For example, a user with attestations from Gitcoin Passport (proving GitHub commits) and World ID (proving unique humanity) demonstrates a costly-to-forge identity graph. This approach is foundational for retroactive public goods funding (RPGF) and fair airdrops, where preventing bot farms is critical. Protocols like Optimism's Citizen House use this to allocate millions in governance power.

Token-Holding-Based Sybil Scores take a different approach by quantifying economic stake and skin-in-the-game. This strategy results in a trade-off: it is highly resistant to low-cost, high-volume attacks but can marginalize non-capital-rich participants. Systems like ve-token models (Curve, Balancer) or simple NFT-gated access use this method. The metric is clear and on-chain—total value locked (TVL) or voting power is directly measurable. However, it can lead to plutocracy, where influence scales linearly with capital, as seen in early Compound and Uniswap governance proposals.

The key trade-off: If your priority is egalitarian access, real-human verification, and cost-effective spam resistance for applications like quadratic funding or reputation systems, choose Attestation-Based scoring. If you prioritize economic alignment, straightforward sybil-cost calculations, and systems where influence should mirror financial stake (e.g., protocol treasury management or collateralized lending), choose Token-Holding-Based scoring. The optimal choice is dictated by whether your system values proof-of-personhood or proof-of-stake as the primary sybil resistance mechanism.

Attestation-based scores (e.g., Gitcoin Passport, World ID) excel at establishing a unique, persistent human identity independent of capital. This is achieved by aggregating verifiable credentials from sources like government IDs, social accounts, and biometric proofs. The primary strength is decentralization and accessibility, as it doesn't require users to hold or lock capital. For example, Gitcoin Passport has been used to distribute over $50M in grants with significantly reduced sybil attack rates, proving its efficacy for permissionless, equitable distribution.

Token-holding-based scores (e.g., EigenLayer restaking, veToken models) take a different approach by using economic stake as a proxy for identity. This results in a high-cost, high-security trade-off. The system's security is directly tied to the value of the staked assets, making attacks economically prohibitive. However, this creates a barrier to entry, favoring users with existing capital. Protocols like EigenLayer secure billions in TVL by leveraging this cryptoeconomic security, but it inherently centralizes influence among the largest token holders.

The key trade-off: If your priority is maximizing accessibility, censorship resistance, and proof-of-personhood for applications like universal basic income (UBI) or democratic governance, choose attestation-based systems. If you prioritize maximizing economic security and aligning user incentives with protocol health for high-value DeFi slashing or curated registries, choose token-holding-based systems. The optimal choice is dictated by whether you value a broad, permissionless user base or a deeply financially committed, albeit smaller, participant set.