ProofEdu

Inspiration Every hiring cycle, millions of students and graduates are required to send unredacted academic transcripts and diploma scans to recruiters, job portals, and scholarship boards. In doing so, they inadvertently expose sensitive personal identifiable information (PII)—including home addresses, government IDs, detailed course-by-course letter grades, and low-scoring electives—just to prove basic eligibility like "Is your GPA above 3.5?" or "Do you have Python proficiency?". Traditional credentials force an all-or-nothing trade-off: either surrender complete privacy by handing over a raw transcript, or fail verification. We were inspired by the Midnight Network's privacy-first architecture to create ProofEdu—a decentralized platform where students hold sovereign ownership over their academic data, proving selective qualifications with mathematical certainty while keeping private details strictly confidential. What it does ProofEdu is a Zero-Knowledge selective disclosure credential verification platform powered by Midnight smart contracts written in Compact. Self-Sovereign Student Vault: Students securely store university-issued academic credentials locally on their devices, protected by private cryptographic salts and SHA-256 commitments. Selective Disclosure Proof Builder: Instead of sharing an entire transcript, students toggle only the specific criteria required by an employer (e.g., CGPA , Python verified, Graduation ). The client executes Zero-Knowledge circuits to generate an on-chain proof. Instant Public Verifier Portal: Employers and admissions officers can verify claims in real time ( ) using a Proof ID. The smart contract validates the cryptographic proof against the Midnight blockchain ledger without learning the candidate's identity or exact GPA. Privacy Contrast Engine & Contract Inspector: Provides interactive side-by-side audits illustrating data leakage prevention and includes a live inspector for the deployed ProofEdu.compact contract and ledger state. How we built it Smart Contract Layer (Midnight Compact DSL): Authored ProofEdu.compact implementing the dual-state model. Private data remains within the client's witness context, while public assertions and verified claim structures (ClaimProofRecord) are committed to the Midnight public ledger state. Cryptographic & ZK Circuit Pipeline: Designed SHA-256 packed hashing schemes, private salt injection, and arithmetic constraint evaluation for threshold range checks and bitmask skill verifications. Frontend & Visualization: Built with React 18, TypeScript, Tailwind CSS, and Lucide Icons, incorporating interactive pipeline animations, audit summaries, and exportable JSON attestation receipts. Backend & Middleware: Node.js/Express service orchestrating Midnight indexer RPC simulation, contract artifact distribution, and resilient client-side fallback engines. Challenges we ran into Emulating Midnight’s Dual-State Paradigm: Designing smart contracts in Compact required a shift from traditional public blockchains (like Ethereum) to Midnight’s separation of private witness data and public disclose() ledger states. Precision Floating Point Comparisons in ZK: Compact circuits operate over bounded unsigned integers. We implemented fixed-point scalar transformations (scaling GPAs by , e.g., ) to enable strict inequalities without floating-point rounding errors. Resilient Offline Proof Generation: Ensuring that network latency or sandbox container constraints would never interrupt a demonstration by embedding a client-side cryptographic proof engine that mirrors on-chain Compact circuits. Accomplishments that we're proud of True 0% Personal Data Leakage: Built a working prototype where recruiters receive verifiable proof of qualifications while candidate transcripts, names, and exact grade distributions remain completely hidden. End-to-End Compact Contract Integration: Successfully compiled and deployed ProofEdu.compact with custom structs, witnesses, and circuit assertions. Intuitive User Experience: Transformed complex zero-knowledge cryptography into a seamless 3-step workflow that any student or non-technical recruiter can use in seconds. What we learned How to architect decentralized applications for privacy-preserving blockchains using the Midnight Compact DSL. The power of ZK-SNARKs and selective disclosure in replacing outdated, high-risk document verification systems. How to structure cryptographic commitments and witness structures to prevent correlation attacks while preserving public auditability. What's next for ProofEdu University Issuer Portal: Build an authenticated dashboard for accredited universities to batch-sign and issue verifiable credentials directly to students' Midnight wallets (e.g., Lace wallet integration). Automated Job Board Integrations: Create API plugins and browser extensions for platforms like LinkedIn, Greenhouse, and Lever so candidates can submit one-click ZK proofs directly into job applications. Multi-Credential Merkle Trees: Support cross-institutional degree credentials, professional industry certifications, and decentralized identity (DID) standards like W3C Verifiable Credentials.