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

Pallet	What It Covers
`pallet-people`	Personhood registration, alias-issuing, and the `under_alias` runtime origin. The foundational pallet the rest of the set depends on.
`pallet-game`	Personhood-gated on-chain games and randomized selection flows.
`pallet-score`	Personhood-anchored reputation and scoring primitives.
`pallet-identity`	The identity record on People Chain associated with a PoP account.
`pallet-ubc`	Universal Basic Capacity — the per-person on-chain capacity primitives.
`pallet-coinage`	The personhood-aware peer-to-peer payment surface behind the App's Coinage feature.

Where to Go Next

Ring-VRF and Aliases

The cryptographic and runtime mechanism — how PoP produces unlinkable per-Product aliases, what under_alias is, and the privacy property the whole stack delivers.

→ Reference
pallet-people

The foundational pallet of the PoP set — registration, alias-issuing, and the under_alias runtime origin.

→ Reference