Proof of Personhood¶

Introduction¶

Proof of Personhood (PoP) is Polkadot's privacy-preserving "real human" check. The Polkadot App is the only place PoP verification happens. When a user completes PoP, they do it on their phone, in the App, once. From then on, a single proof unlocks the developer-facing surface area that gates on personhood, including the TestNet faucet, short .dot names, and any alias-gated feature inside a Polkadot Product.

The App's role is narrow but load-bearing. It runs the verification flow, registers the result on the People Chain, and produces Ring-VRF aliases on demand for Products that ask for one through the Host API. Products see the aliases, not the underlying identity.

Ring-VRF Aliases¶

A Ring-VRF alias is a context-specific pseudonym derived from the user's PoP-anchored identity. Aliases have three properties Product developers depend on:

• Anchored in personhood: An alias only exists for users who have completed PoP. A valid Ring-VRF proof over an alias is also a valid proof of personhood for the user behind it.
• Scoped to a context: The default context is the requesting Product's .dot domain. The same user produces a consistent alias each time they return to your Product, but a different alias for any other Product.
• Unlinkable across domains: Two Products cannot correlate that they share a user unless the user explicitly grants a cross-domain alias.

The App is the side of the system that holds the alias-producing material. A Product's call to app.wallet.getAnonymousAlias() resolves to the App on the user's phone, which signs the alias request.

PoP Tiers: Full vs. Lite¶

The People Chain recognizes two personhood tiers, both registered in the App:

• PoP Full: Cryptographically proven personhood. The user completes the full verification flow in the App: a biometric scan plus ongoing peer-attestation via recurring online sessions. The user's key joins the active membership ring on the People Chain. PoP Full holders can generate zero-knowledge proofs that they are a real person without revealing which one.
• PoP Lite: Third-party attestation. An attester authorized by governance submits an on-chain attestation that an account belongs to a real user. The account is then registered against a separate lite-people ring on the People Chain alongside a communication identifier and a username. Lite supply is bounded by governance, which is the spam-resistance mechanism. Lite holders can produce lite-ring Ring-VRF proofs but do not yet hold membership in the full personhood ring.

Lite is the on-ramp; Full is the destination. The dotNS registrar uses tier to gate which name lengths a user can register for free. See dotNS PopRules Pricing for the full PopRules tier table.

What This Unlocks for a Product¶

A Product running inside Polkadot Desktop can reach the App's PoP surface in two ways via @parity/product-sdk:

• Alias-gated features: Call getAnonymousAlias() for the user's per-Product alias, then createProof(challenge) to prove control of that alias against a challenge. Gate features on the proof rather than on the user's account address.
• On-chain personhood gates: Dispatch calls under the under_alias runtime origin against PoP pallets (e.g. pallet-people). The runtime verifies the underlying Ring-VRF proof and the called pallet's view of the caller is the alias, not the underlying account.

Where to Go Next¶