Privacy matters: a guide to sending encrypted messages anonymously

Big Brother Watch Team / April 19, 2023

The surveillance state is rapidly expanding and our ability to hold private conversations online is under attack. If social media platforms have enabled borderless, wireless communication, they have also opened the floodgates to intrusive, personalised advertising, tracking, and monitoring. You can face privacy risks even on personal messaging apps. There’s a fly on your cyber wall, and it is there for good.

This can pose a challenge to whislteblowers and others who may wish to send us information or tips anonymously.

So, how can you send and receive messages anonymously?

This guide details how messages can be sent anonymously on Signal (for mobile), a secure messaging platform. You can download Signal from the website. You can choose either Android or iOS (for iPhones).

Why Signal? Signal uses a strong security technology called end-to-end encryption which ensures that the messages you send cannot be read by anyone other than the sender and receiver of that message – not your cell phone provider, internet provider, or even people at Signal.

However, Signal, like many other messaging services, asks for a phone number at the time of registration. A phone number can reveal your identity.

If you do not want to give away your personal, primary number to Signal users, you can follow simple steps to set up Signal using a second phone number to protect your anonymity.

Here’s how you can use a separate phone number for Signal

You register a Signal account via a mobile phone number. The easiest way to get a second phone number is by purchasing a SIM card with a cheap SMS service using cash.

For this phone number to be ‘anonymous’, you must not use it for anything else connected with your identity. You will only need this second phone number for Signal to receive verification codes via texts or voice calls.

If you are new to Signal and installing it for the first time, you can find steps for installation here.

If you already have Signal on your phone, which uses your personal, primary number, the following section should be helpful.

Here is how you can additionally use Signal with a separate number for secure, anonymous interactions:

On Android phones or tablets

Set up a new account: The simplest way to use two Signal accounts on one device is by setting up a new ‘user account’ on your Android phone. Each account is associated with its own set-up apps and contacts. So adding a new account should allow you to install Signal with a new number.

To do this:

  1. Head to settings on your app.
  2. Tap on ‘accounts and backup’ and then select ‘users’.
    On some devices, you might find the option to add a new user by navigating to device settings. Look for ‘system’ and then scroll down to find the option, ‘multiple users’.
  3. Tap on ‘add user’.
  4. Click ‘ok’ after reading the text on the ‘add user’ dialogue box.
  5. Select ‘set up now’ and follow any remaining instructions. Make sure that you set up this new user profile in a language that suits you.

The Android phone or tablet will now be ready to use on this brand-new user account. Each user account is associated with an option to install its own set of apps. So, follow installation instructions after downloading Signal from Play Store on this new account.

Note: the process for setting up a new account may differ based on your device.

On iPhones

Sadly, iPhones do not support multiple Apple accounts, so it is not possible to set up two separate Signal phone numbers on the same iPhone. Your anonymous Signal number will have to be your only Signal account on that device.

If you are already using Signal using your personal number and don’t want to replace that for an anonymous Signal account, you will have to use a different device. You can now buy cheap second hand iPhones in many Cash Converters, second hand electronics shops, or online stores like Backmarket.

Important additional steps for security

After you set up a signal account using a second phone number, depending on your risk assessment, you may want to set a Signal Registration Lock PIN. This ensures that nobody can register a Signal account using your second number without knowing your PIN.

To do this:

  1. Go to ‘settings’ menu on the Signal app.
  2. Settings -> Account -> Registration Lock
  3. Choose a strong lock PIN and have a safe strategy to make sure you don’t forget it.

Tips to remember

Remember that each Signal account is associated with a safety number. This verifies the security of your interaction with any other Signal user. You can find it when you select ‘view safety number’ after tapping on any user’s name on Signal.

Each time you uninstall and reinstall the app, Signal updates all your contacts with the following warning message: ‘safety number changed’

It is always advisable to verify safety numbers.

We hope this guide is useful to you.

Privacy is power. It protects us from intrusion, unwanted influence, and authoritarian control. Whether you’re a public figure or an ordinary citizen, protecting private conversations online is a part of our fight for a free future.

You can join us too in our fight to protect privacy and defend civil liberties: Become a Big Brother Watch Supporter — Big Brother Watch