Tamper-proof certificates, without blockchain
A certificate is only as good as your ability to prove it wasn’t altered. QRCertificates makes every credential tamper-proof using cryptographic signing — not blockchain, not “security by hosting”.
How it works
When a certificate is issued, its canonical data — the recipient, course, date, issuer, and certificate ID — is signed with an Ed25519 private key. The public verification page recomputes that signature over the data it’s shown. If even one character has changed, the signature no longer matches and verification fails.
- Sign the data, not the PDF. Re-exporting a PDF can quietly change it; signing the underlying fields means any edit is caught.
- Detectable, not just “hosted”. Security doesn’t depend on a certificate living at a particular URL — it depends on cryptography anyone can re-check.
- No blockchain needed. You get tamper-evidence with proven public-key cryptography, without a chain, tokens, or gas fees.
Why not blockchain?
Blockchain adds cost and complexity to solve a problem that a digital signature already solves cleanly. Ed25519 signing gives you the same “can’t be forged or altered” guarantee, verifiable instantly and for free.
Why make it verifiable?
A certificate that’s just a PDF can be edited, copied, or faked in seconds. Every certificate issued with QRCertificates carries a unique QR code and short code that resolve to a free public verification page. Each credential is Ed25519-signed, so changing a single character — a name, a date, a grade — breaks verification. No login, no app, no blockchain, and verification is free forever.
FAQ
Are certificates tamper-proof without blockchain?
Yes. QRCertificates signs the underlying certificate data (not the PDF) with Ed25519, so changing a single character breaks verification — proven public-key cryptography, without the cost or complexity of blockchain.
What does Ed25519 signing mean for a certificate?
It means each certificate carries a cryptographic signature over its canonical data. The verification page recomputes and checks that signature, so any alteration — a name, grade, or date — is detected.
Is verification free?
Yes — anyone can verify a QRCertificates credential for free, with no login or app.