A simple and reliable security tool

Focus on what's essential, Seald makes it easy to secure your emails, attachments and documents.

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Effortless for the sender and the recipient

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Easily secure your documents

Secure any document (Office, PDFs, videos ...) with a drag and drop in the Seald application. Once secured, the document can be safely sent through any communication channel you want.

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    Military-grade end-to-end encryption
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    Easy to use
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    Any kind of data
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    No password required
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Integrations for your communication tools

The Seald integration allows you to instantly encrypt and decrypt your emails and documents directly in the messaging tool, such as Microsoft Outlook, thus avoiding round-trips between the encryption tool and the communication tool. Smooth workflow for the user.

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    One-click encryption
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    Automatic contact selection
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    Protect drafts
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A decryption client in your documents

With Seald technology, recipients can open documents without installing the software. To do this, the decryption of the email or document takes place in the web browser, after checking the identity of the recipient.

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    No installation required
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    Open in 2 steps
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    Local decryption
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On your phone or on your computer

The Seald mobile app allows you to open your secure emails and documents directly on your device. In addition, it will allow you to authenticate in one single step when opening an email or document on a computer where you can not install the Seald software.

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Desktop client

Remove the authentication steps to open your emails and secure documents with the Seald desktop client and work on your documents seamlessly.

All the answers to your questions

Does Seald have access to my emails or documents?

No. Emails and documents that you secure with Seald never go through our servers.

Can I send an email or a secure document to someone who does not have Seald?

Yes. Indeed, in this case Seald becomes a trusted third party and decryption will be achieved by an authentication of the recipient in the browser.

Which algorithms are used?

Seald follows the recommendations of NIST and ANSSI on encryption.

We have implemented 2 encryption modes:

End-to-end encryption mode: This mode is used when the transmitter and the recipient both have Seald. Seald secures emails and documents using the AES-256/CBC algorithm and is verified by HMAC-SHA256. The message keys are secured by RSA-4096, using a private key which never leaves your local machine.

Authenticated encryption mode: This mode is used when the recipient does not have the Seald app. Seald secures emails and documents using only the AES-256/CBC algorithm and becomes a trusted third party, decryption will be accomplished by authentication of the recipient in the browser.

With which platforms is Seald compatible?

Seald is compatible with macOS, Windows and Linux computers. We plan to release versions for iOS and Android, and potentially other platforms as requested.

Can I use Seald for free?

Seald offers a free version, which can be used to encrypt and decrypt documents manually. Enterprise and Server versions are also offered, with additional features dedicated to team managers or system administrators.

Does Seald need an Internet connexion to work?

Yes. Seald needs an Internet connexion for encryption and decryption.

Seald is not the default app to open .shtml files anymore

To make Seald the default app to open .shtml files, follow these steps: right-click on a .shtml file -> properties -> open with -> select the Seald application