How-To Guides

How to Use Encrypted Messaging

Signal is the gold standard for private messaging -- open-source, end-to-end encrypted, no ads, no data collection. This guide shows you how to set it up and use it well.

Why Signal?

Most messaging apps claim to be "secure" while quietly collecting who you talk to, when, and how often. Signal is different. It is recommended by privacy researchers, journalists, and security professionals worldwide.

  • •Open-source. The full source code is published and auditable. Anyone can inspect the cryptography, and many independent researchers have.
  • •End-to-end encrypted by default. Every message, call, and file is encrypted on your device and only decrypted on your recipient's device. Not even Signal's servers can read your messages.
  • •No ads, no trackers. Signal is funded by donations and grants from the nonprofit Signal Foundation. There is no advertising business model.
  • •No data collection. Signal stores almost nothing about you -- just your phone number (required) and the date you registered. No contact graph, no profile data, no usage analytics.
  • •Recommended by experts. The EFF, privacy journalists, whistleblowers, and security trainers all point to Signal as the messaging default.

If you are picking exactly one private messaging app, Signal is the answer. The setup is the same on every platform. Let's walk through it.

Step 1. Install Signal

Signal has apps for Android, iOS, and desktop. Install on your phone first -- the desktop app is linked to your phone, not standalone.

Android

Open the Play Store, search Signal, and install the app published by Signal Foundation. On some devices you can also install from signal.org directly.

iOS

Open the App Store, search Signal, and install the app published by Signal Messenger, LLC.

Desktop (Windows, Mac, Linux)

Visit signal.org/download and grab the installer for your platform. Linux users can install via apt (official apt repo), flatpak, or snap.

Verify the publisher before installing. Signal is copied by scammers -- the official publisher is always Signal Foundation or Signal Messenger, LLC.

Step 2. Register Your Account

Signal uses your phone number as your identifier. This is a deliberate trade-off -- It makes onboarding frictionless, but means Signal is not fully anonymous. For most people this is fine.

  1. 1.Open Signal. Tap Get Started or Continue.
  2. 2.Select your country and enter your phone number. Use the number you want contacts to reach you at.
  3. 3.Signal sends an SMS verification code to that number. Enter the code in the app to confirm.
  4. 4.Set a profile name and optional avatar. This is what contacts see in chats. It does not have to be your real name.
  5. 5.Open Settings (tap your profile icon top-left). Tap Privacy then Registration Lock PIN. Set a memorable but strong PIN. This PIN encrypts your backup and protects your account if your phone is lost.
  6. 6.Write down your PIN in a password manager. If you forget it, you can lose access to encrypted backups and need to wait 7 days to reset registration.

Why a PIN? Your PIN encrypts your encrypted backup and protects you if someone steals your phone number via SIM-swap. Take 90 seconds to set it well.

Step 3. Start Chatting

Signal messages are end-to-end encrypted only between Signal users. To get full encryption your contacts also need Signal installed -- so start by inviting the people you message most.

  1. 1.Open the app and tap the pencil / compose icon to start a new chat.
  2. 2.Pick a contact from your address book. Signal automatically detects which contacts have Signal installed. Contacts without Signal appear with an Invite button next to their name.
  3. 3.Tap Invite to send an SMS with a Signal download link. Once they install and register, future messages between you route through Signal automatically.
  4. 4.Compose your message and send. The lock icon confirms end-to-end encryption is active.
  5. 5.Send photos and files by tapping the paperclip or plus icon. Files are encrypted the same way as messages.
  6. 6.Make an encrypted voice or video call by tapping the phone or camera icon in any chat.

Step 4. Explore Security Features

Signal has several powerful privacy features hidden just below the surface. Enable the ones that fit your threat model.

Disappearing Messages

Open a chat. Tap the contact's name at the top. Tap Disappearing Messages and choose a timer -- anywhere from 30 seconds to 1 year. After the timer expires the message deletes from both your device and your contact's. Great for sensitive conversations.

Screen Lock

Open Settings then Privacy. Enable Screen Lock and choose a timeout. Signal now requires Face ID, Touch ID, or your device PIN to unlock. Even if someone grabs your unlocked phone, they cannot open Signal without re-authenticating.

Block Screenshots

In Settings → Privacy, enable Block screenshots in chat list. On Android you can also block screenshots inside individual chats. This prevents someone who has your unlocked phone from capturing your conversation list.

Read Receipts and Typing Indicators

In Settings → Privacy you can toggle read receipts, typing indicators, and delivery receipts off if you prefer minimal metadata leakage about your habits.

Step 5. Set Up the Desktop App

Signal Desktop lets you type on a real keyboard and sync messages from your phone. The desktop app is a companion -- it links to your phone rather than functioning standalone. Your phone must remain online periodically for sync to keep working.

  1. 1.Install Signal Desktop from signal.org/download on Windows, Mac, or Linux.
  2. 2.Open the desktop app. You will see a QR code.
  3. 3.On your phone, open Signal and tap your profile icon. Tap Linked Devices.
  4. 4.Tap the + (plus) button and scan the QR code displayed on your desktop screen.
  5. 5.Give the linked device a name (e.g., "Office Laptop"). Recent chats will sync to the desktop app over the next minute.
  6. 6.Note: desktop is a companion to your phone, not a standalone account. If your phone's Signal account is removed, the desktop session logs out too.

Important: As of recent Signal releases, the iPad and desktop apps can register independently as a "Linked Device" or " companion device" (no phone required). Phones remain the default for most users.

Step 6. Signal vs WhatsApp

It is natural to ask: "WhatsApp is also end-to-end encrypted -- why bother switching?" Both apps use the Signal Protocol for encryption. The difference is not the encryption itself. The difference is everything around it.

  • •Same encryption. Both apps use the Signal Protocol for end-to-end message encryption. The actual message contents are protected the same way.
  • •WhatsApp collects metadata. WhatsApp logs who you talk to, when, how often, your contacts list, and group memberships -- and shares this metadata with its parent company and other Meta services for targeted advertising.
  • •Signal collects almost nothing. Signal stores only the phone number and the registration date. There is no metadata about your contacts, your patterns, or your groups.
  • •Signal is open-source and auditable. WhatsApp's encryption is open but its app is closed. You have to trust that WhatsApp's app does not collect more than stated.
  • •Different business models. WhatsApp is owned by an ad company. Signal is run by a nonprofit foundation funded by donations.

If your threat model includes "stop feeding an ad network my social graph," Signal is the obvious choice. If your only concern is that messages cannot be read in transit, WhatsApp technically suffices.

Quick Tips

  • •Signal uses your phone number as your identifier. If you need stronger anonymity, consider a secondary number or a service like MySudo for compartmentalized identities.
  • •Sealed Sender hides metadata about who is sending a message to whom. It is on by default for people in your contacts -- you can enable it for everyone in Settings → Privacy → Sealed Sender.
  • •Your encrypted backup is protected by your PIN. Without the PIN, the backup is unrecoverable. Make sure the PIN is saved somewhere safe.
  • •Keep the app updated. Signal ships regular security and feature updates via the Play Store or App Store. Turn on automatic updates for it.
  • •Verify safety numbers with contacts you suspect might be targeted. Tap the contact name in a chat, then View Safety Number, and compare the numbers in person or via another channel.

Need More Help?

Privacy messaging setups touch every device you own. If you want help auditing your current setup, migrating your most important contacts, or understanding your specific threat model, book a free call with StarCaller Academy.

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