🔐 Signal Messenger
Encrypted Communications
Set up Signal Messenger for military-grade encrypted calls, texts, and video. The most secure messaging app recommended by security experts worldwide.
⚠️ Most Secure Messaging App Available
Signal is the gold standard for encrypted communications. Used by journalists, activists, whistleblowers, and security professionals worldwide. Even if your network is compromised, your messages remain private with end-to-end encryption.
What is Signal?
Signal is a free, open-source messaging app that provides:
- 🔐 End-to-end encryption - Only you and recipient can read messages
- 📞 Encrypted voice/video calls - Secure phone and video calls
- 🔇 No data collection - Signal doesn't store your messages or metadata
- 🌐 Open source - Code is publicly audited
- 💰 Free forever - No ads, no subscription, funded by donations
- ⏱️ Disappearing messages - Auto-delete after set time
💡 Why Signal vs iMessage or WhatsApp?
iMessage: E2EE but only works with other Apple users. Metadata stored by Apple. SMS fallback is not encrypted.
WhatsApp: E2EE but owned by Meta (Facebook). Collects metadata. Shares data with Facebook.
Signal: E2EE, open source, no metadata collection, works cross-platform, nonprofit organization.
Step 1: Download and Install Signal
1 Download Signal from App Store
Search for "Signal Private Messenger" in the App Store or use the link below.
Download Signal2 Open Signal and Grant Permissions
Signal will request permissions for:
- ✅ Notifications - To alert you of new messages (required)
- ✅ Contacts - To find friends using Signal (optional but recommended)
- ✅ Camera - For video calls and photos (optional)
- ✅ Microphone - For voice/video calls (optional)
3 Register Your Phone Number
Enter your phone number. Signal will send a 6-digit verification code via SMS.
Note: Your phone number is used for registration but is NOT visible to other users unless they have you in their contacts.
4 Set Up Your Profile
Add a profile name and optional photo. This is what other Signal users will see.
Privacy tip: Use a nickname instead of your real name if you're concerned about privacy.
✅ Signal is Installed!
Now let's configure it for maximum security.
Step 2: Configure Security Settings
1 Enable Screen Lock
Go to Settings → Privacy → Screen Lock
Turn ON Screen Lock and choose timeout (30 seconds recommended)
This requires Face ID/Touch ID to open Signal, even if your phone is unlocked.
2 Enable Registration Lock
Go to Settings → Account → Registration Lock
Turn ON Registration Lock and create a PIN
This prevents someone from registering Signal with your number on another device.
3 Set Default Disappearing Messages Timer
Go to Settings → Privacy → Disappearing Messages
Set a default timer (1 week recommended, or shorter for high-security needs)
Messages will auto-delete after this time period.
4 Disable Message Previews in Notifications
Go to Settings → Notifications → Show
Select "Name Only" or "No Name or Message"
This prevents message content from appearing on your lock screen.
5 Enable Sealed Sender
Go to Settings → Privacy → Sealed Sender
Turn ON "Allow from Anyone"
This hides your sender information from Signal's servers, providing extra metadata protection.
Step 3: Verify Safety Numbers
Safety numbers ensure you're communicating with the right person and not an imposter.
How to Verify Safety Numbers
- Open a conversation with a contact
- Tap their name at the top
- Scroll down and tap "View Safety Number"
- Compare the 60-digit number with your contact in person, via video call, or through another secure channel
- If they match, tap "Mark as Verified"
When to verify: For sensitive communications with journalists, lawyers, activists, or anyone under threat.
Signal vs SMS: What's the Difference?
| Feature | Signal | SMS/iMessage |
|---|---|---|
| Encryption | ✅ End-to-end always | ⚠️ iMessage only (not SMS) |
| Metadata Protection | ✅ Minimal metadata | ❌ Full metadata stored |
| Voice/Video Calls | ✅ Encrypted | ⚠️ FaceTime only |
| Disappearing Messages | ✅ Yes | ❌ No |
| Open Source | ✅ Yes | ❌ No |
| Cross-Platform | ✅ iOS, Android, Desktop | ❌ Apple only |
| Data Collection | ✅ None | ⚠️ Some (Apple) |
Advanced Signal Features
Disappearing Messages (Per Conversation)
Set custom timers for specific conversations:
- Open a conversation
- Tap the contact's name
- Tap "Disappearing Messages"
- Choose a timer (30 seconds to 4 weeks)
Note to Self
Signal includes a "Note to Self" conversation - an encrypted space to save notes, photos, and files. It's like a private, encrypted notepad.
Group Chats
Signal supports encrypted group chats up to 1,000 members. All messages remain end-to-end encrypted.
Voice/Video Calls
Make encrypted voice and video calls. Signal will show a verification code during calls - compare with the other person to ensure security.
Who Should Use Signal?
- 🗞️ Journalists - Communicating with sources
- ✊ Activists - Organizing protests and campaigns
- ⚖️ Lawyers - Attorney-client privilege protection
- 🏥 Healthcare workers - HIPAA-compliant communication
- 🚨 Domestic violence survivors - Private communication away from abusers
- 💼 Business professionals - Sensitive corporate communications
- 👤 Anyone who values privacy - Your messages are your business
Limitations to Be Aware Of
- ⚠️ Requires phone number - Not anonymous (use burner phone for anonymity)
- ⚠️ Both parties need Signal - Can't send encrypted messages to non-Signal users
- ⚠️ Metadata still exists - Signal knows when you're online (but not who you're talking to)
- ⚠️ Device security matters - If your phone is compromised, messages can be read
Troubleshooting
Q: Can Signal be subpoenaed?
A: Yes, but Signal has almost no data to provide. They only store: phone number, date registered, and date last connected. No messages, contacts, or metadata.
Q: Is Signal really secure?
A: Yes. Signal's encryption protocol is considered the gold standard and is used by WhatsApp, Google, Facebook Messenger, and others. It's been audited by security researchers worldwide.
Q: Can my employer/ISP see my Signal messages?
A: No. They can see you're using Signal, but not who you're talking to or what you're saying.
Q: What if I lose my phone?
A: Your messages are stored locally. If you lose your phone, messages are gone (unless you backed them up). This is a security feature - no cloud storage means no cloud breaches.
Last Updated: January 24, 2026
Part of the AIMF Security iPhone Defense Guides
