P2PReputation

Problem: 15M+ P2P traders lost their reputation when LocalBitcoins and Paxful shut down. Platform lock-in prevents reputation portability.

Solution: Bring Binance P2P reputation on-chain with privacy preservation.

Key Features:

• Privacy-first:Nullifier = hash(userNo + wallet). NO Binance identity on-chain.
• zkTLS proofs: Reclaim Protocol verifies reputation without API access.
• Ultra-cheap:<$0.001 per attestation on Sui.
• Client-side only:No backend, no database, no accounts.

HackMoney Project Build Overview

We built a privacy-preserving P2P reputation system using a minimal, client-side-first architecture designed for speed and sustainability.

Core Tech Stack Frontend Layer: Next.js 14 + React with TailwindCSS and TypeScript. We leveraged @mysten/dapp-kit for seamless Sui wallet integration, eliminating custom auth logic.

Proof Generation (The Secret Sauce): We used Reclaim Protocol's zkTLS SDK for two-step proof validation. Here's the "hack"—we chain two proof requests sequentially:

Public proof of Binance P2P reputation (anyone can verify the score) Auth proof (user proves they own the account without leaking identity) This two-step approach gives us both verifiability and privacy in ~15 seconds, which is fast for zero-knowledge proofs.

Privacy Layer: We use ethers.js only for keccak256 hashing—creating privacy-preserving nullifiers so users can't be tracked across transactions.

Blockchain: Sui L1 was a game-changer. Sub-second finality + $0.0001 transaction fees meant we could afford attestation proofs for everyone. Our Move smart contract stores privacy-preserving attestations (just hashes, no PII).

Why This Architecture Won Zero backend/database = deployed on Vercel free tier, scales infinitely 12 npm dependencies = builds in <30s, minimal attack surface Sponsor-aligned = built on Sui, for Sui, using Reclaim for zkTLS Shipped in 9 days = simplicity enabled speed No Docker, no CI/CD, no Redis, no state management library—just the essentials.