How certification works

NULLA certification is designed to be minimal, private, and verifiable over time.

It proves only one thing: that a specific digital object already existed at a given moment.

Once issued, a NULLA certificate cannot be altered or revoked.

The core principle

NULLA does not receive, store, or inspect digital objects.

Instead, it certifies a unique digital fingerprint derived from the object, generated locally by the user.

Step by step

1. The user selects a digital file on their own device.
2. A unique digital fingerprint is generated locally, without uploading the file.
3. Only this fingerprint is sent to NULLA.
4. NULLA records the time and issues a signed certificate.
5. The user keeps both the original file and the certificate.

Privacy by design

Because NULLA never receives the original file, it cannot know what is being certified.

No content, metadata, identity, or context is collected or required.

Future verification

At any point in the future, verification is simple.

The fingerprint of the original file is generated again and compared with the one recorded in the certificate.
If they match, the object is proven to be the same one that existed at the certified time.

What this does not prove

• Authorship or ownership
• Truth or accuracy
• Intent or meaning
• Legal validity

---

NULLA preserves a minimal trace of existence, so that the past cannot be silently rewritten.