What end-to-end encryption means
Your messages pass through the app company’s servers on the way to the other person. With ordinary encryption, they’re scrambled on the journey but the company can unscramble them on its servers. That means it can read them, scan them, hand them over when asked, or lose them in a breach.
End-to-end encryption (E2EE) means the scrambling happens on your phone, and only the other person’s phone holds the key to unscramble it. The company carries messages it can’t read. If its servers are hacked, or a court demands the contents, there’s nothing readable to give.
The decision that matters: who you need to reach
The most private app is no use if nobody you talk to has it, so the real question is which app your people will install. Signal is the one to suggest. It’s free, it works on iPhone, Android and computers, and day to day it feels like any other messaging app.
You don’t have to move everyone at once. Start with the people you talk to most, or the family group chat, and keep WhatsApp or iMessage for anyone who won’t switch.
What encryption protects, and what it doesn’t
End-to-end encryption protects the content: messages, photos, voice notes and calls. It doesn’t protect:
- Metadata. Who you talk to, when and how often. Some apps record a lot of this. Signal is designed to keep almost none.
- Backups. A copy of your chats saved to iCloud or Google Drive is only as private as that backup. Check whether your app’s backup is end-to-end encrypted too.
- The phones themselves. Anyone who can open your phone, or the other person’s, can read the chat. A good screen lock matters as much as the app.
- The other person. They can screenshot or forward anything you send.
What it needs
- A phone, iPhone or Android. For most people, signing up also needs a phone number that can receive a text. Signing up without a number is a paid option in testing on Android.
- No money. Signal is run by a non-profit, the Signal Technology Foundation, and paid for by donations. There are no adverts.
- For a computer, Signal Desktop for Windows, Mac or Linux, which links to the account on your phone.
How Signal fits in
- Everything encrypted by default. Every chat, group, voice call and video call, with nothing to switch on.
- Very little kept. Signal publishes the legal requests it receives. The only account data it has been able to hand over is the date an account was created and the last time it connected.
- Your number kept private. By default, only people who already have your number saved can see it. You can set a username to share instead, and change or delete it whenever you like.
- Disappearing messages. Set a chat to delete messages after a time you choose, or make that the default for new chats.
- Signal PIN and registration lock. A PIN you choose protects your account. With registration lock on, someone who gets hold of your phone number also needs that PIN to take over your Signal account.
- Linked devices. The desktop and iPad apps link to your phone by scanning a code.
- Optional encrypted backups. Secure Backups are locked with a 64-character recovery key that only you have. The free level keeps your text messages and the last 45 days of photos and videos, and a paid level keeps more.
The easy way to set it up
It’s an ordinary app from the app store, with no account to create beyond your number.
- Install Signal from the App Store or Play Store.
- Register with your phone number. Signal texts you a code to confirm it.
- Choose a Signal PIN when asked, and save it in your password manager.
- Set a profile name and a username in Settings, Profile.
- Check who can see your number. In Settings, Privacy, Phone Number, choose who can see it and who can find you by it.
- Turn on registration lock in Settings, Account.
- Add your computer. Install Signal Desktop from signal.org. On your phone, go to Settings, Linked devices, and scan the code shown on the computer.
- Bring people in. Signal shows which of your contacts already use it. For a group, create it in Signal and share its invite link in the old chat.
Questions people ask
Can Signal read my messages?
No. Messages are encrypted on your phone and only the recipient’s phone can decrypt them. Signal’s servers pass along scrambled data they have no key for.
Why not WhatsApp, if it uses the same encryption?
The contents of your messages are protected in much the same way. The difference is everything around them: WhatsApp belongs to Meta and collects far more about who you talk to and how you use the app, as the comparison below explains.
What happens when I get a new phone?
During setup, Signal can move your chat history straight from the old phone if you have it to hand. If you’ve turned on Secure Backups, you can restore from those with your recovery key instead. Without either, your account moves across but your old messages don’t.
Do the people I message need Signal too?
Yes. Signal only talks to other Signal users. It no longer sends ordinary text messages, so anyone without it has to be reached another way.
