OpenProof
LivePrivacy-first proof-of-existence on Base Sepolia. Next.js 16 + Solidity/Foundry. AGPLv3. Live at proof.kovina.org.
1. Blockchain Proof Without File Uploads
Your files never leave your device. OpenProof hashes files locally using the Web Crypto API (SHA-256) and sends only the resulting bytes32 hash to a minimal Solidity contract on Base Sepolia. The original document stays on your machine. This is proof of existence without exposure — you can timestamp a file's fingerprint onchain without revealing its contents to anyone.
2. Canonical Receipt Specification (v3)
Every proof generates a versioned, deterministic JSON receipt with an Ed25519 signature. Receipts are printable and PDF-friendly, with citation formats for APA, MLA, Legal, and Plain text. The specification is an open standard designed for cross-app interoperability — any tool that understands the format can verify any proof.
3. Bundle Proofs with Merkle Tree Verification
Prove multiple files at once with deterministic combined hashes via a sorted Merkle tree. Each file gets an individual inclusion proof that can be verified independently. The verification report runs 11+ checks — schema validity, chain state, contract state, onchain consistency, bundle integrity — producing a pass/fail result you can trust.
4. Public Proof Pages with QR Verification
Each proof generates a shareable page at /proof/[hash] that reads the public registry state without exposing the original file. QR codes on printed receipts encode the proof page URL — not the file itself. Print or export as PDF for physical records. Anyone can verify without installing software or trusting a third party.
5. PWA and Multi-Platform Packaging
OpenProof ships as an installable PWA, a Capacitor Android app, and an MSIX Windows package. Lighthouse 100 scores across performance, accessibility, best practices, and SEO. A full threat model document is maintained in the repository, and v1.0 has a strict feature freeze to prevent scope creep.
Part of the Kovina ecosystem
A collection of open-source tools built for ownership, permanence, and everyday use.
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