Technical

End-to-End Encryption: How it works

E2E is the foundation of secure communication. Here's how it works — without the jargon.

The postcard analogy

Regular email is like a postcard: every mail carrier can read it. End-to-end encryption is like a sealed envelope: only the recipient can open it.

How it works

  1. Alice wants to send Bob a message
  2. Bob's device creates a key pair: public + private
  3. The public key goes to Alice
  4. Alice encrypts with Bob's public key
  5. Only Bob's private key can decrypt it
  6. Even the server (WhatsApp, Signal) can't read it
Why this is secure

The public key can't decrypt. Only the private key on Bob's device can. This is mathematically proven. Even the most powerful computers in the world can't crack it in any reasonable time.

Why Chat Control undermines E2E

Chat Control bypasses encryption without breaking it. The trick: client-side scanning.

Normally

You type → encrypted → server → recipient decrypts. Server sees only noise.

With Chat Control

You type → AI on your phone analyzes → if "ok" → encrypted. Surveillance BEFORE encryption.

The problem

You won't notice. Encryption still works. But a third party has already read the content.

Which messengers have E2E?

MessengerE2E DefaultE2E CallsOpen Source
SignalAlwaysYesYes
WhatsAppAlwaysYesNo
ThreemaAlwaysYesYes
TelegramSecret Chats onlyYesYes
⚠️ Telegram warning

Telegram does NOT have E2E by default. Only "Secret Chats" are encrypted. Normal chats and groups are NOT E2E encrypted. Telegram can read the content.

Encryption is your right

Download Signal →