Secure Messaging: Signal vs Default Apps
Your phone's default SMS and call apps are convenient. They're pre-installed, everyone's on them, and they work out of the box. But here's the uncomfortable truth: they're not secure. Not even close.
Every text you send, every call you make with your carrier's default apps—your carrier can read it all. Law enforcement can subpoena it. Advertisers can buy it.
Let's talk about why that is, and what you can do about it.
Why Default Carrier Apps Are Insecure
Traditional SMS and phone calls were designed for functionality, not privacy. Here's what you're dealing with:
- No end-to-end encryption — Your carrier can read every message. They have the keys.
- Extensive metadata logging — Who you called, when, for how long. All stored.
- Vulnerable to SIM swaps — Attackers can hijack your number with enough social engineering.
- Easy to subpoena — Carriers readily comply with legal requests. They keep logs.
- No encryption at rest — Messages stored on your phone and carrier servers, unencrypted.
Your carrier knows your entire communication history. Every person you've texted, every call you've made, when you made it, and how long it lasted. They can hand this over with a subpoena—or sell it to advertisers.
Signal: The Gold Standard
Signal is an encrypted messaging app that has become the gold standard for secure communications. Here's why:
Signal's Security Features
- End-to-end encryption by default — Even Signal cannot read your messages. The encryption key lives only on your device and the recipient's device.
- Open source and audited — Security researchers can verify the code. No hidden backdoors.
- Minimal metadata — They don't log who you message or when. They literally can't hand over what they don't have.
- No access to contacts or messages — Your data stays on your device.
- US-based — Not perfect, but better privacy laws than many alternatives.
The only real downside: both parties need Signal installed for end-to-end encryption to work. However, Signal can replace your default SMS app, falling back to unencrypted SMS only when necessary.
Other Secure Messaging Options
iMessage
- Encrypted if both parties use iPhones
- Warning: Apple can decrypt messages. They hold the keys and comply with legal requests.
- Good option if everyone you know is in the Apple ecosystem
- End-to-end encrypted by default
- Massive user base—everyone already has it
- Concern: Owned by Facebook/Meta
- Meta has a long history of monetizing user data
SimpleX Messenger
- No phone number required
- More privacy-focused design
- Smaller user base
- Good for highly sensitive communications
Comparison Table
| App | E2E Encryption | Metadata | Phone # Required |
|---|---|---|---|
| Signal | Yes (default) | Minimal | Yes |
| iMessage | Yes (Apple devices) | Some | Yes |
| Yes (default) | Significant | Yes | |
| SimpleX | Yes | Minimal | No |
| Carrier SMS | No | Extensive | Yes |
Recommendations
- Primary choice: Signal. Best balance of security and usability. Get everyone you know on it.
- For Apple users: iMessage is a decent fallback, but remember Apple can decrypt.
- For maximum privacy: Consider SimpleX—no phone number required.
- Avoid: Default carrier SMS for anything sensitive.
- Be wary of: WhatsApp given Meta's data practices.
The Bottom Line
Never trust carrier SMS for sensitive communications. Your carrier can read everything, stores extensive metadata, and readily complies with legal requests.
Signal provides the best combination of security and ease of use. It's open source, audited, and minimizes metadata. The only requirement is that both parties use it.
End-to-end encryption only works when both parties use it. That's the biggest hurdle—but it's also why it works. When you message someone on Signal, you're both protected.
The best time to switch to Signal was years ago. The second best time is today.
Start by getting one person in your life to switch. Then another. Build the habit. Your communications will thank you.