Issuer: Kusama Proof-of-Personhood (PoP) Bounty
RFP Release Date: April 2026
Proposal Deadline: Rolling submissions. The curators reserve the right to close submissions at any time with reasonable notice
There are multiple Digital Individuality Mechanisms (DIMs) for Proof-of-Personhood (PoP) currently being developed by Parity as part of Polkadot's native PoP framework:
| DIM | Mechanism | Examples |
|---|---|---|
| DIM1 | Physical uniqueness tattoo | Proof-of-Ink |
| DIM2 | Synchronized online participation | Ring VRFs |
However, the ecosystem currently lacks a social-graph-based PoP mechanism where individuals attest to the humanity of others.
A Web-of-Trust (WoT) model allows people to build a decentralized social graph where identities mutually vouch for each other. Properly designed, such systems can:
This RFP seeks proposals to design and implement a privacy-preserving social-graph-based PoP system suitable for experimentation within the Kusama ecosystem.
The objective of this RFP is to develop a Web-of-Trust-based Proof-of-Personhood system where individuals mutually attest to each other's humanity. The system should:
The system should be implemented as an experimental DIM for Kusama.
Proposals should include the following components:
The system must allow individuals to attest to the humanity of others through trust edges in a social graph. Proposals must clearly distinguish between personhood (uniqueness) and reputation (trust quality). The primary goal of this RFP is Proof of Personhood, not reputation.
The attestation protocol should support:
Proposals must address how the renewal mechanism resists automation, since periodic renewal is burdensome and creates an incentive to automate.
Proposals must explain how uniqueness is established beyond simple accumulation of trust.
The system must not require any specific third party that could censor or deny participation to an individual in order to attain any level of PoP confidence. Designs that depend on centralized identity verification services (e.g., KYC providers) or any single external entity as a prerequisite for personhood attestation are out of scope for this RFP.
Proposals must describe a bootstrap strategy for early adoption, including: the minimum network size needed for the system's privacy and security properties to hold, how the system provides meaningful guarantees during the early phase, and how it transitions from a small trusted seed to an open permissionless network without creating a de facto permissioned system.
The system must protect the privacy of participants and their social relationships. The system should:
Graph queries must maintain k-anonymity, with k ≥ 100 once adoption is sufficiently large. Proposals must define what network size is needed to achieve this threshold and how the system behaves below it.
Instead of exposing raw graph data, the system should enable users to prove statements such as:
"I am likely a unique human participant
with confidence ≥ X
derived from ≥ N unique individuals."Proposals that use a confidence, score, or probabilistic measure of personhood must clearly define:
Approaches may include zero-knowledge proofs, aggregated confidence metrics, or privacy-preserving graph queries.
Social graph systems are vulnerable to fake identity clusters. Proposals must explicitly address mitigation of: Sybil clusters, collusion rings, trust farming, dormant identity attacks, and reputation laundering.
The design must not rely on permissioned graph analysis. Possible approaches include: trust-flow algorithms (e.g., SybilRank-style models), weighted trust propagation, reputation decay, edge creation costs, stake or bonding requirements, and anomaly detection mechanisms.
Proposals must define the adversary model under which the system operates, including:
Proposals must explain how the system ensures that contributing individuals are themselves likely to represent distinct humans, rather than coordinated or duplicate identities.
Privacy preservation and Sybil detection are in fundamental tension: the more the graph is hidden, the harder it is to detect fake identity clusters. Proposals should explicitly discuss how they balance these goals and articulate the tradeoffs their design makes.
Proposals must include a user-facing application (native mobile, PWA or equivalent) for iOS and Android that enables users to interact with the system. Given the experimental nature of this RFP, teams may propose a progressive web app or simplified prototype for initial milestones, with native user-facing apps as a later milestone or optional enhancement.
The application should support:
Identity Pairing
User Capabilities
Users should be able to:
The application should prioritize usability, privacy, and security.
The system must support mechanisms allowing Web2 services to verify proof of personhood. Possible approaches include:
Logins must provide contextual pseudonymity: each user must be able to present a unique pseudonym per service, and pseudonyms across different services must be unlinkable, even if those services collude.
The goal is to enable personhood-aware services such as:
Proposals must include at least one demonstration application that benefits from unique human participation. Examples include:
The demonstration should clearly show why unique human identities matter.
Proposals must include following deliverables:
Teams may optionally include:
Proposals will be evaluated across the following areas, listed in approximate order of priority. Curators reserve discretion in how these criteria are balanced across proposals. Across all criteria, reviewers will consider whether the proposal clearly defines its model, inputs, assumptions, and limitations.
Proposals must be submitted through the Kusama Vision PoP Bounty submission form. Submissions must clearly indicate they are in response to this RFP. Submissions require a proposal document hosted on Fileverse using the provided template, along with contact details for curator coordination via Matrix.
All deliverables must be open sourced under one of the following licenses: GPL ≥ 2, MIT, or Apache 2.0. Acceptance of the PoP Bounty charter and transparency commitments is required at submission.
Proposals must address each of the evaluation areas outlined in Section 6, and include:
Given the experimental nature of this RFP, budgets are not fixed. However, proposals should aim to balance scope, feasibility, and impact, and clearly justify all requested funding.
Proposals must define a reference currency for the total amount requested. Funding will be disbursed in DOT on Kusama AssetHub on a milestone basis. Proposals must include:
Proposals must also link a detailed budget spreadsheet (dSheets or equivalent decentralized spreadsheet) breaking down costs per milestone by role, estimated hours, rates, and any non-labor costs (e.g., infrastructure, audits, tooling).
Curators may negotiate milestone structure and amounts before approval. Partial funding may be offered where scope adjustments are appropriate.
Participants
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Mutual Trust Attestations
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Privacy-Preserving Graph
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Personhood Confidence Proof
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Web3 Applications Web2 ServicesThe goal of this RFP is to produce an experimental Web-of-Trust PoP mechanism for Kusama that:
The resulting system may serve as an additional Digital Individuality Mechanism (DIM) alongside other PoP approaches as they become available across the Polkadot and Kusama ecosystem.
Interested in building this? Submit your proposal through the PoP Bounty submission form.
Submit a Proposal