DiplomaChain

Universities issue diplomas and certificates that are anchored on Polygon, so anyone can verify one without trusting the platform it came from. The issuer signs the credential, the platform anchors its hash on-chain, and verification checks three things: that the issuer held on-chain authority at the time of issue, that the signature is valid, and that the anchor hash exists on the chain.

What makes that worth doing is what it does not require. Verification reads blockchain state and nothing else — if the platform disappeared tomorrow, every credential it ever issued would still verify. No personal data goes on-chain at all, payloads are encrypted at rest under per-tenant keys, and anchoring batches through a Merkle tree so a graduating class costs roughly one transaction instead of a thousand.

It is multi-tenant, and isolation is enforced at the query layer rather than by convention: the tenant travels in the token and middleware injects it into every database query, so a forgotten filter cannot leak one university's records into another's. React and TypeScript on the front, Fastify and Prisma behind it, Solidity contracts on Polygon, and a separate worker that submits, confirms and reconciles on-chain operations asynchronously.