End-to-end encryption made simple.

The Seald SDK handles all the complex cryptography and key exchanges. Integrate end-to-end encryption into any applications in hours, without cryptographic skills.

Wimi Framatome psa Lefebvre Sarrut Recare Doktor Lpg
Wimi Framatome psa Lefebvre Sarrut Recare Doktor Lpg
How it works

Designed for application developers

Import the SDK

Import the SDK

Create a free account, retrieve your API keys and import the SDK in your app.



Call sdk.encrypt() on any sensitive data. It is encrypted locally for the authorized users only.



The encrypted data is sent to your backend through your regular API calls.



Your backend stores the encrypted data at rest. No one except authorized users can decrypt it.

Our differences

Blazing fast, invisible and scalable end-to-end encryption technology

A certified technology

The only end-to-end encryption SDK certified in the world

The Seald SDK benefits from a certification issued by the ANSSI (the French cybersecurity agency). The technology has been audited by third-party experts, based on compliance analysis and advanced penetration testing, which ensures you a robust security model.

Did you know?

Our technology comply with today and tomorrow’s regulations, like HIPAA, GDPR, CCPA, PCI DSS and more.

Recovery methods

Users can never lose access to their data

Seald provides a recovery mechanism (without backdoor) called the "2-man-rule". It allows a user to recover their private key even when all passwords and devices are lost. It's based on secret splitting between independent servers that authenticate independently the user.

Did you know?

The Seald SDK offers several recovery methods: by password, locally or in "2-man-rule". The private key must be available and confidential, otherwise data can be lost or leaked.

Absolute trust

The Sig-Chain

Seald developed the "Sig-Chain" technology, an unalterable register in which is recorded every operation of adding identity, entering a group, renewing keys, etc. A chain of signatures specific to each user, which ensures that no-one can perform a man-in-the-middle attack.

Did you know?

The "Sig-Chain" is a mechanism that allows to check all the public keys of a user at once, and any public key that might be added afterwards using the TOFU paradigm.

Our advantages

All the complexity is on our side

  • Zero-trust

    No server is trusted. The confidentiality of encrypted data is ensured, even if the Seald servers are breached.

  • Groups management

    Encrypt data for a group of users. You can modify the members of this group. New members have access to the history.

  • Recovery methods

    If a user loses their password or device, they can always recover access to their encrypted data.

  • Integration support

    Seald provides high-quality documentation and examples. The support team is available for any questions.

  • All platforms

    The Seald SDK is available for web, mobile or desktop applications, and for most languages.

  • Access rights management

    Change the recipients without changing the encrypted data. It is also possible to remove someone's rights.


Quickly integrate encryption into your applications with Seald SDKs. You don't need skills in cryptography to integrate them.

import SealdSDK from '@seald-io/sdk'

// Initialize the SDK
const seald = SealdSDK({ apiURL, appId })
// Create your Seald identity
await seald.initiateIdentity({ signupJWT })
// Encrypt a message for another user
const encryptedMessage = await seald.encryptMessage(
  'Super secret message',
   { userIds: ['BOB_002'] }

// And *voilà*!
const message = await seald.decryptMessage(encryptedMessage)