Signal Desktop – Secure Encrypted Messaging Application

Complete Guide to Signal: Privacy-Focused Encrypted Messaging

Signal has become the gold standard for secure, private communication, offering end-to-end encryption that protects messages, calls, and media from everyone except the intended recipients. Developed by the nonprofit Signal Foundation, this open-source application provides the security features demanded by journalists, activists, and privacy-conscious users while maintaining the simplicity expected from modern messaging apps.

Unlike many messaging platforms that collect extensive user data, Signal’s design philosophy minimizes data collection to near zero. The application stores virtually no metadata about your communications, and its open-source nature allows security researchers to verify these privacy claims. Available on mobile and desktop platforms, Signal enables secure communication across devices.

Installing Signal Desktop

# Ubuntu/Debian (official repo)
wget -O- https://updates.signal.org/desktop/apt/keys.asc | gpg --dearmor > signal-desktop-keyring.gpg
sudo mv signal-desktop-keyring.gpg /usr/share/keyrings/
echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https://updates.signal.org/desktop/apt xenial main' | sudo tee /etc/apt/sources.list.d/signal-xenial.list
sudo apt update
sudo apt install signal-desktop

# Flatpak
flatpak install flathub org.signal.Signal

# Arch Linux
yay -S signal-desktop

# macOS
brew install --cask signal

# Windows
winget install OpenWhisperSystems.Signal

# Verify installation
signal-desktop --version

# Mobile apps
# iOS: App Store
# Android: Play Store or signal.org/android

Initial Setup

# Setting up Signal:

# 1. Mobile first (required):
Install on iOS or Android
Verify phone number with SMS code
Create PIN for account recovery
Set up profile (name, photo)

# 2. Link desktop:
Open Signal Desktop
Click "Link phone to Signal Desktop"
Scan QR code with mobile app

# Desktop linking:
Mobile app > Settings > Linked Devices
Scan QR code on desktop
Desktop syncs conversation history

# Multiple devices:
Link up to 5 devices
All receive messages
Messages synced across devices

# Account PIN:
Settings > Account > Signal PIN
Required for account recovery
Enables Registration Lock

Messaging Features

# Basic messaging:
End-to-end encrypted by default
No configuration needed
Green checkmarks = delivered/read

# Message options:
- Text messages
- Voice messages
- Photos/videos
- Files (any type)
- GIFs
- Stickers
- Contact cards
- Location sharing

# Formatting:
*bold text*
_italic text_
~strikethrough~
`monospace`

# Disappearing messages:
Conversation > Settings
Enable disappearing messages
Set timer (5s to 4 weeks)
Messages auto-delete

# View-once media:
Send photo/video
Tap infinity icon
Recipient can only view once

# Message reactions:
Long-press message
Select emoji reaction

# Reply and quote:
Long-press > Reply
Quote specific message
Threaded conversations

# Edit messages:
Long-press > Edit
Within 24 hours of sending
Shows "Edited" indicator

Voice and Video Calls

# One-on-one calls:
Encrypted voice and video
Tap phone/camera icon
HD quality when available

# Group calls:
Up to 40 participants
Video or voice only
Screen sharing supported

# Call features:
- Mute microphone
- Toggle video
- Switch cameras
- Speaker mode
- Blur background
- Raise hand
- Share screen

# Call links:
Create call link
Share with anyone
They join via link

# Desktop calling:
Fully supported
Same encryption as mobile
Need microphone/camera access

Group Chats

# Create group:
New message > New group
Add members
Set group name and photo

# Group administration:
Add/remove members
Edit group info
Set who can edit
Set who can add members

# Group permissions:
- Anyone can send
- Only admins can send
- Who can edit group info
- Who can add members

# Announcements-only groups:
Only admins post
Members can react
Good for broadcasts

# Group links:
Create invite link
Share to invite
Reset link to invalidate

# Leave group:
Long-press group > Leave
Your messages remain for others
No notification to group

# @mentions:
Type @ followed by name
Notify specific people
@all mentions everyone

Privacy Features

# Safety Numbers:
Verify contact identity
Settings > View Safety Number
Compare with contact
Mark as verified

# Screen security:
Settings > Privacy > Screen Security
Block screenshots in app
Prevents in recents view

# Incognito keyboard:
Settings > Privacy
Request keyboard incognito mode
Disables learning/predictions

# Sealed sender:
Hides sender info from server
Enabled by default
Maximum metadata protection

# Read receipts:
Settings > Privacy
Enable/disable read receipts
Blue double-check when read

# Typing indicators:
Settings > Privacy
Show/hide typing status

# Registration lock:
Settings > Account > Registration Lock
Requires PIN to re-register
Prevents number hijacking

# Block contacts:
Long-press conversation > Block
They can't message you
They won't know they're blocked

Backup and Restore

# Android backup:
Settings > Chats > Chat backups
Create encrypted backup
Save 30-digit passphrase!
Store backup file safely

# Restore on Android:
Install Signal
Select "Restore from backup"
Locate backup file
Enter 30-digit passphrase

# iOS backup:
Enable iCloud backup
Chats included (encrypted)
Or: Transfer during setup

# Transfer between devices:
Settings > Chats > Transfer account
QR code transfer
Direct device-to-device

# Desktop data:
Messages stored locally
Not backed up to cloud
Link new desktop = fresh start

# Note:
Desktop doesn't backup independently
Mobile is source of truth
Keep mobile backed up

Desktop-Specific Features

# Keyboard shortcuts:
Ctrl+N: New conversation
Ctrl+Shift+N: New group
Ctrl+F: Search
Ctrl+Shift+M: Minimize to tray
Ctrl+,: Settings
Ctrl+Q: Quit

# Desktop notifications:
Settings > Notifications
- Message preview
- Name only
- No name or message

# System tray:
Minimize to system tray
Receive notifications
Quick access

# Spell check:
Enabled by default
Right-click for suggestions

# Audio/video devices:
Settings > Calls
Select input/output devices
Test before calls

# Dark mode:
Settings > Appearance
Light, dark, or system default

# Conversation preferences:
Right-click conversation
Pin, archive, mute, delete

Note to Self

# Personal space:
Message yourself
Syncs across devices
Useful for:
- Quick notes
- File transfer
- Link saving
- Voice memos

# Access:
Search "Note to Self"
Or tap your own contact

# Same encryption:
End-to-end encrypted
Only you can read
Even on multiple devices

Stories

# Signal Stories:
24-hour posts
Photos, videos, text
End-to-end encrypted

# Create story:
Tap camera from home
Take/select media
Share as story

# Story privacy:
- All Signal connections
- Selected contacts only
- Custom groups

# View stories:
Tap story circle
Swipe for next story
Replies start conversations

# Hide stories:
Settings > Stories
Hide from specific people
Or disable entirely

# Desktop stories:
View stories on desktop
Create on mobile only

Troubleshooting

# Common issues:

# Messages not arriving:
Check internet connection
Verify Signal running
Check notification settings
Battery optimization off

# Desktop not syncing:
Re-link device if needed
Check internet on both devices
Restart both apps

# Notification problems:
System notification settings
Signal notification settings
Battery optimization exceptions

# Call quality:
Check internet speed
Close other apps
Try Wi-Fi vs cellular

# Can't verify safety number:
Contact may have reinstalled
New device = new numbers
Re-verify if trusted

# Reset application:
Unlink and re-link desktop
Clear cache if available
Reinstall as last resort

# Report issues:
Settings > Help > Contact Us
Include debug log if needed

Conclusion

Signal represents the best of privacy-focused technology, providing robust encryption without sacrificing usability. Its commitment to minimal data collection and open-source development has earned trust from security experts and privacy advocates worldwide. Whether coordinating sensitive communications or simply preferring privacy, Signal delivers secure messaging that respects users’ fundamental right to private conversation.