ML-KEM-1024 | FIPS 203 | CSPN ANSSI Chiffrement souverain post-quantique

Let's talk encryption

A question about post-quantum encryption, a need for an audit, or an integration project? We'll get back to you within 24 business hours.

Zero-knowledge communication — Your message is encrypted in your browser (RSA-4096 + AES-256-GCM) before transmission. The transit infrastructure only sees opaque data. Only the recipient holds the decryption key. Learn more
End-to-end encrypted before sending

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Thank you. Your message was encrypted in your browser and is now being processed. We will get back to you within 24 business hours.

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How your data is protected

1
Encrypted in your browser

Before any transmission, your message is encrypted locally in your browser using an ephemeral AES-256-GCM key. This key is then wrapped with our RSA-4096 public key (RSA-OAEP-SHA256). The plaintext never leaves your device.

2
Opaque transit

The encrypted payload travels through Cloudflare. The Cloudflare infrastructure (Workers, KV Storage) only handles opaque data — it does not have the private decryption key and has no access to your message content. The fields you filled in (name, email, message) are invisible to any intermediary.

3
Sovereign decryption

Decryption occurs exclusively on Cryptosphere's sovereign infrastructure, hosted in France. The RSA-4096 private key is stored only on our servers, under our exclusive control. No third party — including our transit infrastructure provider — has access to it.

4
No personal data in cleartext at Cloudflare

Cloudflare never sees your name, email or message content. The only visible element is your IP address (required for network routing). Metadata stored in Cloudflare KV is limited to a unique identifier, a timestamp and the encrypted blob.

5
Automatic deletion

Encrypted data is automatically deleted after processing. No personal data persists in the transit infrastructure.

Only Cryptosphere SAS, as data controller, has access to your personal data in cleartext. This level of protection is identical to what we provide for our clients' critical infrastructure.

Headquarters

19 rue du Colisée
75008 Paris, France

Lab

R&D and integration
Rouen, France

CSPN Ready · EAL4+ Ready