You'd think discussions about military operations wouldn't be happening over smartphone messaging apps. Yet, in what's now possibly the most infamous group chat ever, top U.S. officials—including the Vice President and Secretaries of Defense and State—were reportedly using Signal to discuss bombing plans in Yemen. The kicker? A journalist was accidentally added to the chat.

This odd blunder naturally raises a question for the rest of us: Just how secure are the messaging apps we use every day? Let's break down the privacy features of some of the most popular platforms.

Signal: Widely Considered the Gold Standard

Signal is often hailed as the most secure messaging app available to consumers. It uses end-to-end encryption (E2EE) via the open-source Signal Protocol, meaning only the intended recipient can read your messages—even Signal can't see them.

Key security features include:

Because the app is open source, third-party experts can audit its security, adding an extra layer of trust.

iMessage: Excellent—If Everyone Has an iPhone

Apple's iMessage is also end-to-end encrypted, but unlike Signal, its protocol is proprietary, meaning it isn't publicly available for inspection.

That said, Apple is known for strong security, and iMessage boasts:

However, there are caveats:

WhatsApp: Strong Encryption, But Metadata Concerns

WhatsApp also uses the Signal Protocol, offering end-to-end encryption by default for messages, voice calls, and media. The downsides?

Still, WhatsApp is widely used and offers the best group chat features, making it a convenient option for many.

Telegram: Not Truly End-to-End by Default

Telegram is often considered secure, but it's not end-to-end encrypted by default. Standard messages are encrypted during transmission and when stored, but Telegram's servers can access them.

To get true E2EE, you have to create a Secret Chat, which also allows:

If privacy is your priority, Telegram falls short compared to Signal or WhatsApp.

Messenger: Slowly Getting There

Once the rollout completes, Messenger could match WhatsApp in terms of security, but it's not there yet.

The Real Takeaway: Human Error is the Weakest Link

Encryption only works if you're careful with who's in the chat. The recent high-profile incident isn't a failure of encryption—it's a reminder that no security feature can protect you from accidentally messaging the wrong person.

So yes, Signal, WhatsApp, and iMessage all offer strong privacy protections. But no app can stop you from adding a journalist to a top-secret group chat.