Key Takeaways

  • Signal Protocol: The gold standard. Open Source and verified by experts. It encrypts not just the message content, but also minimizes metadata (who talked to whom).
  • Telegram's Flaw: Telegram cloud chats are NOT End-to-End Encrypted. The server has the key. Telegram employees can technically read your messages unless you use "Secret Chats."
  • WhatsApp: Uses the Signal Protocol (Good), but collects massive Metadata (Bad). Facebook knows exactly who you speak to and when, even if they can't see the text.

If the service is free and not open source, assume there is a backdoor.

The Metadata Problem

Encryption hides the content: "Meet me at 5 PM."
Metadata reveals the context: "User A messaged User B at 4:55 PM, location NYC."

For intelligence agencies, Metadata is often more useful than content. Signal is designed to know nothing. When served with a subpoena, Signal can only provide "Account Created Date" and "Last Login Date." They have no other data to give.

Feature Comparison

Feature Signal WhatsApp Telegram
E2E Default? Yes Yes No
Metadata? Minimal High (Meta) Medium
Owner? Non-Profit Facebook Pavel Durov

Session App

A fork of Signal that removes the need for a Phone Number. It routes traffic through an onion-style network (Oxen) for even greater anonymity. Great for those who don't want to share their SIM info.

Frequently Asked Questions (FAQ)

Is SMS safe?
No. SMS is sent in plain text. Your carrier (and anyone with a Stingray device) can read it. Never share secrets via SMS.
What about "Disappearing Messages"?
Useful for hygiene (keeping database small), but not for security. Someone can always take a photo of the screen with another camera.

Shield your devices from signals.
Read Faraday Bag Guide