The third anchor · Who?

Your seal.
Your digital continuity.

The DfinA Vault seal is a personal seal that only you can reproduce. It does not replace an official identity: it links a series of files to a single declared origin and lets you prove that you control it.

✓The file stays on your device ✓The secret phrase is never transmitted ✓The seal can be verified by anyone
Visible and recognizableThe pattern and its code can be displayed publicly.
DfinA VaultPersonal seal
DF-8A7C-41E9
"PRO" seal
Seal passphrase
Seven words known to you alone
Impossible to reproduce without the secretCopying the image of the seal does not let anyone answer a signature challenge.
The principle

Three certainties, without entrusting us with anything.

DfinA Vault sees neither your file nor your identity. Yet three elements can remain under the control of you and your recipients.

The exact content

The cryptographic fingerprint makes it possible to verify that the file is strictly identical, byte for byte, to the one that was certified.

What? · Integrity

A date

The certificate sets a point in time. With Premium, the fingerprint also benefits from an independent anchoring in the Bitcoin blockchain.

When? · Existence

One and the same seal

The seal links several documents to a pattern that its holder can reproduce and whose control they can demonstrate.

Who? · Continuity
The right definition

A mark of continuity, not an identity card.

The seal does not prove your civil status. It proves that the same seal recurs across a series of documents and that you are able to reproduce it or to sign a challenge with it. The more it is used and publicly claimed, the more recognizable it becomes.

✓
It establishes continuityA body of work, creations, reports or photographs bear the same seal.
✓
It resists mere imitationCopying the design of the seal does not grant the ability to sign a challenge.
≠
It does not certify a civil identityIts attribution rests on the way you claim it and have it recognized.
In practice

Apply your seal in four steps.

The seal comes into play after the fingerprint is calculated. The seal is created and signed on your device.

Step 1

Choose the file to certify.

Document, photograph, video, audio or archive: the browser calculates its fingerprint locally. The content never leaves your phone or computer.

PDFcontract-final-version.pdfFingerprint calculated on this deviceReady
The right habit: always keep the original file. Any change, even invisible to the eye, produces a different fingerprint.
Step 2

Turn on "Apply your seal".

The option is offered once the file is recognized and its fingerprint calculated. It is available with the unlimited plans.

The seal completes the certificate: it replaces neither the fingerprint nor the timestamp.
Step 3

Your seal is born from a seven-word phrase.

This phrase is generated for you or entered on the device. A short label, for example "pro", "personal" or "photo", can create a distinct pattern.

Important: the phrase is the only key that can reproduce the same seal. It cannot be recovered.
Step 4

The seal joins the certificate and its verification.

The visible pattern, its code and the associated signature are embedded in the proof. A recipient can check the file, the seal or both.

DfinA Vault certificateFingerprint · Date · "PRO" seal · Verification QRValidated
You can now keep the certificate with the file or share it with anyone who needs to verify its declared origin.
The secret of the seal

Seven words to keep, a pattern to show.

The security of the seal rests on a very simple separation: the phrase stays private, while the pattern and its code can circulate freely.

Fictional example

The seal passphrase

It reproduces the same seal on any device.

shoreambermistralcobaltforestlightconstellation
No recovery is possible.
If you lose the phrase, the older seals remain verifiable, but you will no longer be able to apply new ones under the same pattern.

To show

Public

The pattern and its code make up your visual signature. They can appear on your website, your profiles and your documents.

  • Graphic pattern
  • Seal code
  • Certificates and verification links

To protect

Secret

The seal passphrase is the ability to reproduce the seal. It must never be shared with a third party.

  • Keep it in a safe place
  • Preserve at least one backup copy
  • Never share it with the certificate

What protects your secret

One-way

The public pattern and its code cannot be used to recover the seal passphrase. Your seal can therefore be displayed without revealing the key that reproduces it.

Organize your uses

One phrase can produce several seals.

A short label added to the phrase creates a distinct pattern and code. You can thus visually separate several activities without multiplying your secrets.

Same phrase, different labels

The resulting seals appear independent to the public. Only you know that they come from the same phrase.

Shared secret phraseseven words kept by the holder
→
PROProfessional activityDocuments, reports, contracts7C41-A9
PHOTOVisual worksPhotographs and creations2F88-D3
PERSOPersonal archivesMemories and private documentsB164-5E
Good to know: these seals share the same phrase. For truly compartmentalized identities, use a separate phrase for each one, with a dedicated subscription.

An immediate reading

The label indicates the context of the seal without revealing your phrase or publicly linking your different uses.

A distinct reputation

Each pattern can be claimed in its own environment: a brand, an artistic activity, a family circle or a project.

A secret to protect

The simplicity of a shared phrase implies a shared fate: losing it prevents you from recreating all the seals that depend on it.

Building trust

A seal gains value when it is claimed.

The design alone is not enough. Trust comes from its regular use, its public presence and your ability to demonstrate that you really hold the secret.

The foundation of reputation

Two complementary steps.

The people around you learn to recognize the seal and can, if needed, ask you for proof of control.

1Claim it publiclyDisplay the pattern on your website, your profiles, your communications or your works.
2Demonstrate control of itSign a challenge phrase offered on the spot, without revealing your secret phrase.
3Use it consistentlyRepetition gradually turns the seal into a familiar and credible marker.
The anti-impersonator proof

The signature challenge

It shows that you really hold the seal, without ever revealing the seven words.

1A third party invents a challengeFor example: "sky-orange-42".
2You sign it on your deviceThe signature is computed from your seal passphrase.
3You send the proof linkAnyone can verify that the holder of the seal signed this exact challenge.
When to use it? In case of doubt, dispute, plagiarism, or when someone wants to verify on the spot that the seal is really under your control.
On the recipient's side

Two independent checks.

You can verify the file, the seal or both. None of these checks reveals the seal passphrase.

01

Verify integrity

Does the file received match exactly the fingerprint in the certificate? The check compares the file and the proof locally.

Requires the file
02

Verify the seal

Does the signature match the announced seal? This verification can be carried out from the link alone, even without having the file.

Possible with the link alone

What the seal provides

  • The visible continuity of a body of documents or works
  • A technical argument against impersonation or plagiarism
  • The ability to prove control of the seal at a given moment
  • A third anchor of origin in addition to the content and the date

What it does not claim to be

  • An automatic proof of your civil identity
  • A qualified electronic signature within the meaning of eIDAS
  • An irrefutable legal decision or a judgment on the content
  • An instant reputation if the seal is never publicly claimed

No one can carry your seal in your place.

The seal is included in the unlimited Essential and Premium plans.

See the plans