# LP-0001: Private NFT Ownership Proof [DRAFT]

**`Status: draft - pending NFT Program readiness`**
**`Logos Circle: N/A`**

## Overview

Token-gating is everywhere — allowlists, governance votes, exclusive channels — but today it requires revealing exactly which token you hold. This prize is for a ZK-based membership proof system that lets a user prove they own *some* NFT from a collection without disclosing *which one*.

The result is a reusable primitive: a Logos Execution Zone (LEZ) contract and a client-side proving workflow that any dApp can integrate to offer privacy-preserving token-gated access.

## Motivation

Current token-gating solutions force users to sign messages that expose their wallet address and the specific token they hold. This leaks on-chain identity, enables correlation attacks, and undermines the pseudonymity that many users rely on. A ZK membership proof — where the proof attests "I own a token in this collection" without revealing which one — is a natural fit for Logos' shielded execution model and closes this gap cleanly.

A competitive prize is the right mechanism here because the problem is well-specified but the implementation space is large: circuit design, nullifier schemes, Merkle tree construction, and gas cost trade-offs all admit multiple valid approaches. Competition surfaces the best solution.

## Success Criteria

### Functionality

- [ ] A user holding any NFT in a given collection can generate a client-side ZK proof of ownership on a standard laptop.
- [ ] The proof can be verified on LEZ without revealing the token ID or the holder's wallet address to the verifier.
- [ ] The system is resistant to proof reuse across contexts — a nullifier or domain-separation mechanism prevents the same proof from being replayed in a different gating context.
- [ ] A reference integration is delivered: a working demo of at least one token-gated action (e.g., allowlist registration or an on-chain vote) using the proof system.
- [ ] At least 5 independent NFT collections are deployed on LEZ testnet with the proof system integrated, each by a distinct team or community outside the submitting team.
- [ ] Full documentation and a clean public repository are delivered.

### Usability

- [ ] Provide a module/SDK that can be used to build Logos modules for interacting with the program.
- [ ] Provide a Logos Basecamp app GUI with local build instructions, downloadable assets, and loadable in Logos app (Basecamp).
- [ ] Provide an IDL for the LEZ program, using the [SPEL framework](https://github.com/logos-co/spel).

### Reliability

- [ ] The system handles proof generation failures gracefully and surfaces a clear error to the user.
- [ ] The verifier program returns deterministic, documented error codes for all invalid-proof scenarios.

### Performance

- [ ] Document the compute unit (CU) cost of each on-chain operation on LEZ devnet/testnet. Note: LEZ's per-transaction compute budget may change during testnet.

### Supportability

- [ ] The program is deployed and tested on LEZ devnet/testnet.
- [ ] End-to-end integration tests run against a LEZ sequencer (standalone mode) and are included in CI.
- [ ] CI must be green on the default branch.
- [ ] A README documents end-to-end usage: deployment steps, program addresses, and step-by-step instructions for interacting with the program via CLI and Basecamp app.
- [ ] A reproducible end-to-end demo script is provided and works against a real local sequencer with `RISC0_DEV_MODE=0`.
- [ ] A recorded video demo of the end-to-end flow is included in the submission; the recording must show terminal output (including proof generation) to confirm `RISC0_DEV_MODE=0` was active.

## Scope

### In Scope

- ZK circuit(s) implementing the membership proof over an NFT collection's ownership set, targeting the Risc0 proving stack.
- A LEZ verifier program (Rust) that accepts and verifies proofs on-chain.
- A client-side SDK or CLI tool for proof generation.
- A reference integration demonstrating at least one token-gating use case (allowlist, voting, or access control) on LEZ testnet.
- Documentation covering the cryptographic approach, any trusted setup requirements, and an integration guide.

### Out of Scope

- Multi-chain or cross-chain ownership proofs.
- A polished consumer-facing UI — a working demo is sufficient.
- Ongoing maintenance or security audits beyond initial delivery.

## Prize Structure

- **Total Prize:** $TBD
- **Effort:** Medium

## Eligibility

Open to any individual or team. Submissions must be original work. Teams must hold the rights to all submitted code and agree to license it under MIT or Apache-2.0.

## Submission Requirements

- Public repository containing all circuit code, LEZ program code, and client-side tooling, licensed under MIT or Apache-2.0.
- Deployment of the verifier program on LEZ testnet, with a verified program ID.
- End-to-end demo video in which the builder narrates what they built and why, walks through the architecture and key implementation decisions, and demonstrates proof generation and on-chain verification for at least one token-gating use case. A silent screencast is not sufficient (see [demo requirements](../README.md#evaluation-policies)).
- A write-up covering: cryptographic approach, proving system used, Merkle tree construction, nullifier/domain-separation scheme, security assumptions, known limitations, and integration instructions.
- Gas cost benchmarks for on-chain verification.
- GitHub issues open for any problem encountered with Logos technology.

## Evaluation Process

Submissions are evaluated first-come-first-served against the success criteria. The first submission that satisfies all criteria wins.

Evaluators will independently clone the repository and run the demo script from a clean environment; the script must succeed without modification. Evaluators may also ask technical follow-up questions to verify authorship and understanding of the implementation.

The following policies apply to all prizes (see [evaluation policies](../README.md#evaluation-policies)):

- **Submissions:** each builder (or team) is allowed a maximum of **3 submissions** per prize, with at most **one submission/review per week**.
- **Feedback:** initial evaluation feedback is limited to a pass/fail indication against the success criteria.

## Resources

- [LEZ Github repository](https://github.com/logos-blockchain/logos-execution-zone)

## Potential for Subsequent λPrizes

TBD