ZecRep
Zcash Reputation Oracle on Ethereum
The problem ZecRep solves
ZecRep gives Zcash users a way to prove their shielded wallet history without revealing balances, so DeFi protocols can grant loans, rebates, or governance power with a verifiable privacy-preserving credential instead of trusting centralized attestations or forcing users to dox their funds.
Describe what people can use it for / how it helps
Lending desks & OTC venues: require a minimum Zcash tier (Bronze → Platinum) before extending credit, without seeing the borrower’s exact balance.
DAOs & governance: gate proposals, voting weights, or Sybil protection via ZecRepGuards.requireTier, ensuring only reputable shielded accounts participate.
Wallets & dApps: integrate the SDK so users can mint/refresh their tier badge directly in-app, with the Proof Wizard showing every stage of the pipeline.
Partners & compliance teams: subscribe to aggregator webhooks + Prometheus metrics to audit job lifecycles, latency, and failure reasons in real time.
Developers: leverage the soulbound badge + FHE range checks to build private loyalty programs, fee rebates, or KYC-lite access controls.
Challenges I ran into
Lightwalletd latency & redundant scans: hitting public endpoints repeatedly was too slow, so I built a disk-backed scan cache (TTL configurable) to memoize Orchard/Sapling totals and unblock rapid prototyping.
Fastify logging + plugin mismatches: Fastify v5 rejects logger objects unless configured properly, and older @fastify/cors versions balked at the new major. I fixed it by exporting typed logger options and upgrading to the v5-compatible plugin.
End-to-end pipeline coordination: the Proof Wizard needed to reflect actual backend job progress—not mock timers—so I rewired the hook to submit/poll aggregator jobs, handle errors, and surface encrypted payloads + total zats live.
README diagrams on GitHub: Mermaid diagrams failed because parentheses break node parsing; quoting node labels made them render correctly for the judges.
Tracks Applied (2)
Privacy Infrastructure & Developer Tools
Zcash Community Grants
General Bounty
Project Tachyon
Technologies used