Proof of Personhood¶

Introduction¶

Proof of Personhood (PoP) is Polkadot's privacy-preserving way to confirm a user is a real human, without exposing which human. A user completes PoP once (in the Polkadot App); from then on, a single proof unlocks personhood-gated features — the TestNet faucet, short .dot names, alias-gated checks inside a Polkadot Product, and on-chain payments routed through personhood-aware pallets.

For a Product developer, PoP shows up in two places:

• As a primitive your Product calls into: Through the Product SDK your Product requests an alias for the current user, has the user prove control of that alias against a challenge, and gates features on the result. The Polkadot App is where the proving happens; your Product never sees the underlying biometric or the user's identity record.
• As a runtime origin your Product dispatches under: Polkadot's PoP pallets accept calls under the under_alias origin, so your Product can submit on-chain operations that resolve to the user's alias inside the called pallet — pallet state stays unlinkable to the underlying account.

This reference is organized into two halves: the mechanism (Ring-VRF, aliases, the unlinkability property, how under_alias works) on its own page, and per-pallet reference for the pallets a Product is most likely to dispatch into.

The Mechanism¶

Ring-VRF and Aliases is the conceptual deep dive: how the PoP cryptography produces unlinkable per-Product aliases, what under_alias is at the runtime layer, and the privacy property the whole stack delivers.

The Pallets¶

Where to Go Next¶