Understanding Zero-Knowledge Encryption

Security isn't just a feature at ContextX—it's the foundation of everything we build. In this guide, we'll explain how our zero-knowledge encryption works and why it matters.

What is Zero-Knowledge Encryption?

Zero-knowledge encryption means that the service provider (us) cannot access your data. Period. Your information is encrypted on your device before it's uploaded, using keys that only you possess.

This is fundamentally different from traditional encryption where the service holds the keys. Even if a company promises not to look at your data, they technically could. With zero-knowledge encryption, they can't.

How ContextX Implements Zero-Knowledge

Here's a simplified overview of our approach:

// Client-side encryption before upload
const encryptedData = await encrypt(userData, userKey);

// We only store the encrypted blob
await storage.upload(encryptedData);

// Even our servers only see:
// "aGVsbG8gd29ybGQ..." (encrypted gibberish)

Key Derivation

When you create your account, a unique encryption key is derived from your master password using PBKDF2 with 100,000 iterations. This key never leaves your device.

End-to-End Encryption

All data is encrypted locally before transmission:

• At rest: AES-256-GCM encryption
• In transit: TLS 1.3
• Key storage: Never on our servers

What This Means For You

1. True privacy: Your data is truly private, not just promised to be
2. Breach protection: Even if our servers were compromised, attackers would get meaningless encrypted blobs
3. No backdoors: We couldn't share your data with anyone even if compelled to

The Trade-off

Zero-knowledge does come with one important consideration: if you lose your recovery phrase, we cannot help you recover your data. There's no "forgot password" option because we don't have your keys.

We provide a 24-word recovery phrase when you sign up. Store it somewhere safe—it's the only way to recover your account if you lose access.

Security is Not Optional

In an age where data breaches are constant news, we believe zero-knowledge encryption should be the default, not the exception. Your personal data is too valuable to trust to anything less.

Questions about our security? Contact us or read our security whitepaper.