Sealway
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How it works

How it works: two ways to build evidence with Sealway.

File, photo, video or document: create the proof from the app. For an email, simply add Sealway in BCC when you send it. Either way you get a dated evidence file that anyone can verify, without Sealway.

Join the waitlist Choose the right mode

What you want to prove decides the mode.

From the app

Files, photos, videos and documents

Select or capture your files in the app, group them into one proof and get a dated, verifiable evidence file.

  • a photo or video taken on the spot, or files that already exist;
  • several files gathered in a single proof;
  • documents, audio files, music, exports, source files.
How to create a proof
From your mailbox

Emails and attachments

Send your email as usual with Sealway in BCC. Sealway receives the message as it is sent and builds the evidence of its content.

  • the message as transmitted, with its attachments;
  • the recipients shown and the headers of the message received;
  • nothing to install, nothing to change in your mail client.
How to prove an email

From there, the path is the same.

Whatever the mode, it is not your content that gets timestamped but its fingerprint: a value computed from the exact content of the file (SHA-512).

Change a single character of the file and the fingerprint changes, and the fingerprint cannot be turned back into the file. It is bound to a qualified electronic timestamp, issued by a qualified trust service provider under the eIDAS Regulation, which enjoys a presumption of accuracy of the date and time and of integrity of the data.

The evidence file holds the certificate, the timestamp token and the fingerprints. It can be verified on any computer, without a Sealway account and without Sealway: the Verification page explains how.

Your content Sealway Fingerprint of the content Qualified electronic timestamp Verifiable evidence file

Which mode should I use?

A simple rule: what exists as a file goes through the app; what gets sent goes through BCC.

The creation mode by what you want to prove
You want to prove The mode
The condition of a place, an object, a site or goods on a given date Photos or videos taken from the app, in one proof
That a document, a creation or a version of a file existed on a given date Files imported into a proof
What you wrote to someone, with which attachments, and when the message left Sealway in BCC when the email is sent
What someone sent you Forward the received message to your Sealway address: the proof dates the forward, not the original sending

Going further

Security File encryption, hosting in Europe, qualified providers: what Sealway does with your data. Verification Verify an evidence file, a timestamp token or a Merkle tree on your own computer, without Sealway. Use cases Property inventory, building site, claim, delivery, product recall, deliverable: how the proof is used in each situation.

Frequently asked questions

What people ask before creating a first proof.

How does Sealway work?
Sealway creates evidence in two ways. From the app, you select or capture files (photos, videos, documents, audio) and group them into a proof. From your mailbox, you add your Sealway address in BCC of an email: Sealway receives the message as it is sent. In both cases Sealway computes the fingerprint of each item, binds it to a qualified electronic timestamp and produces an evidence file that can be verified without Sealway.
Do I need to install anything to prove an email?
No. You write and send the email in your usual mail client, adding your Sealway address, or that of a collection, in the BCC field. The message goes to its recipients as usual; Sealway receives a copy and builds the proof.
Can I create an email proof from the app?
No, by design. An email proof rests on a message actually received by Sealway when it is sent. A .eml file imported afterwards would only prove that the file existed on the date of the import, not that the message was sent: the web app refuses such files. The email evidence guide explains the difference.
What does the evidence file contain?
The certificate, the qualified electronic timestamp token, the fingerprint of each file and the manifest that ties them together, plus the original files for as long as your plan keeps them. The file can be verified without Sealway, with the tools on the Verification page or any software able to recompute a fingerprint and the Merkle tree described on the certificate, then read a timestamp token.

Create your first proof.

From the app or from your mailbox: fingerprint, qualified electronic timestamp, verifiable evidence file. Join the waitlist to be notified at launch.

By signing up, you agree to be contacted by Sealway about the launch. No sharing with third parties.