Proof of Personhood

Proof of Personhood is a category of mechanisms designed to verify that a participant in a digital system is a unique, real human being, without necessarily revealing their identity. This is important for preventing Sybil attacks in systems that require one-person-one-vote fairness, such as airdrops, governance, and universal basic income experiments. Approaches include biometric verification, social graph analysis, and trusted ceremonies. Worldcoin's iris scanning is one of the most well-known (and controversial) implementations.