Add protection against quantum computers to your signatures, and know if anyone removes it.
A powerful enough quantum computer would be able to forge the electronic signatures on today’s contracts and records. Perennis adds a second, quantum-safe signature to the same document. The software you use today opens and checks the document as before. If someone removes or damages the second signature, the Perennis check does not confirm the document and shows what is wrong.
- Today’s signatureThe software you use today checks it as before.
- Quantum-safe signatureAdded by Perennis to the same document.
Evidence · measured 13 Nov 2026
We tried to remove the protection. Here is what happened.
- We signed a real document on our platform.
- We made three copies and broke the quantum‑safe signature in each one, a different way each time.
- We checked all four files with EU DSS, the European Commission’s signature checker, and with Perennis.
| What we changed | EU DSS 6.3* | Perennis |
|---|---|---|
| Quantum-safe signature removed | Valid | Not confirmed |
| One byte changed in its certificate | Valid | Not confirmed |
| One byte changed in the signature itself | Valid | Not confirmed |
EU DSS is not wrong: the classical signature really is untouched. It simply does not check the quantum-safe signature. Perennis does.
* Measured on the document as signed (PAdES-B), with the pilot’s certificate authority added to EU DSS’s trusted list. If the document also carries an archive time-stamp (PAdES-B-LTA), EU DSS reports all three changes as a time-stamp failure. It learns that the file was changed, not that the quantum-safe signature is invalid.
Think of a passport with a chip.
A passport has a photo and a chip. If the border check only looks at the photo, someone can pull out the chip and nobody will notice.
That is how today’s signature checkers work: they look at the classical signature and never look for the quantum-safe one. Perennis checks both.
It never looks for the chip.
ValidYour rules require the chip, and it is missing.
Not confirmedWhy now. Under the EU roadmap, Member States should start moving to quantum-safe cryptography by the end of 2026, and high-risk use cases should move no later than the end of 2030. What the roadmap says →
You change nothing you use today. Your documents simply get one more signature.
Sign as you do today
Your certificate, signature and document format do not change.
Perennis adds a second signature
A quantum-safe signature over the same document, tied to the first so that it cannot be moved to another document.
Both must be valid
The Perennis check confirms the document only if both signatures are valid.
Try it yourself in your browser.
Sign a file with real keys, remove the quantum-safe signature, and watch which checker notices. Nothing leaves your computer.
Try the labWorking today. Certification next.
Done
- A working signing platform, from identity check to long-term archive
- The method, peer-reviewed and published in Cryptography (2026)
- Quantum-safe verification checked against NIST test vectors
- Quantum-safe time-stamps
Next
- Certified hardware for the signing keys
- Independent conformity assessment
- Pilots with trust service providers
Who is behind Perennis
Rumen Doynov
Founder · first author of the peer-reviewed paper that describes the method
Rumen designed and built Perennis: the quantum-safe signature, the signing platform and the check. Based in Sofia, Bulgaria.
Investor or partner? Write directly to contact@perennistrust.eu
Who Perennis is for
Trust service providers and signing platforms
Offer your customers a quantum-safe signature without changing the signature they rely on today.
For providers → ValidationValidation services
One answer on whether a document is valid, after checking both signatures under the ETSI rules.
For validation services → Public sectorAdministrations and European Digital Identity Wallet teams
For records that must still be verifiable decades from now.
For the public sector →