When I join a group, it’s almost always true that the group will be using one or more communication technologies to organise and communicate within the group. Sometimes that is email, sometimes it is Slack, but most frequently it is a messaging app that has a group chat capability. I would like to convince you that the best technology for this purpose will include end-to-end encryption and be built in such a way that the company or organisation that operates or provides the application cannot access the content of your group’s communication - even faced with a warrant. Quite frankly, this is the desirable and privacy-protective option no matter the nature of the group - from knitting circles to strike planning committees. So in this recipe I will take you through the steps you need to move from WhatsApp to Signal, but you should be able to replicate this approach for other messaging apps.
The stakes
When you use technology that doesn’t have these privacy-protective characteristics, a few things happen. Your, and your group’s, metadata is harvested. That means who talked to who, when, and for how long. In a best-case scenario, that is just to serve ads and increase engagement. For example, if you use WhatsApp, you are using an app owned by Meta. Meta licenses the Signal Protocol, which provides end-to-end encryption, but it harvests the metadata.
The metadata tells Meta who you message, when, how often, which groups you are in, and your contact graph - the map of who is connected to whom. If you have ever watched a TV detective or cop show, you might well have seen a whiteboard depicting a criminal organisation showing how everyone is identified and connected. Sometimes this might be presented as a corkboard with pins and red yarn connecting everything. You have been sorted and categorised and are available for targeting and exploitation.
When you use an app like WhatsApp, the company that provides the app becomes included in every group discussion or even direct messages. Signal - the company, not the protocol - is structurally set up so that it cannot do this. That means only the actual participants in a conversation are parties to the conversation.
By using Signal, not only does your group not feed into each member’s ad profile or otherwise become a surveillance subject, but it is also a living demonstration that there IS an alternative to surveillance capitalism.
Time & difficulty
If you can install an app, you are most of the way there. You won’t need deep technical skills. The difficulty will be social. You will need to overcome the reluctance that some members of the group will have to change. They are accustomed to the current situation and will need to be persuaded that the gain at the end of the move will be worth the pain at the start of the move. This really becomes a discussion for the group to have and to work together on.
What you’ll need
You will need a smartphone. Either an iOS phone (Apple) or an Android phone (Google, Samsung, and most others). You can use the desktop Signal app, but it will be linked to the app on your smartphone. But never do this on a work or shared computer unless you want to share your private chats with your employer or whoever else has access to the computer. And for a higher level of privacy, consider using a secondary number (see “Going further” below). When you register, you will have to provide Signal with a phone number to register. You should be aware that installing Signal may send a notification to your contacts that you have joined Signal. You can hide it after registration, and use a chosen username should you choose to do so. You will also need a way to store the Registration Lock PIN should you need to recover your Signal profile and settings after, for example, losing your phone. The PIN prevents someone from re-registering your number. I recommend a password manager, but you could write it down on paper. I will be doing a post on password managers later in this series.
Steps
It’s pretty straightforward to actually install Signal.
You find and install it from the App Store on your phone - where you normally install apps.
When you run Signal the first time, you will be asked to register with the phone number of the phone you are on.
Set up a profile name/photo which will be encrypted and visible only to people you message.
Registration Lock PIN. Go to Settings -> Account and turn on Registration Lock and set a PIN. Write it down or store it in a password manager. Signal can’t reset it. This prevents anyone else from re-registering your number.
Phone number privacy. Settings -> Privacy -> Phone Number
Who can see my number -> Nobody
Who can find me by number -> Nobody
Set a username so people can chat without your number. Both of you will need a recent version of the app for this feature to work.
Disappearing messages. This can be set as a default (Settings -> Privacy -> Default timer for new chats) or per chat with a duration starting in seconds and going up to a few weeks. Note that disappearing only works if the other end doesn’t take a screenshot or photograph.
Lock screen leakage. Remember to hide your message content in lock-screen notification previews (Signal → Settings → Notifications). Otherwise messages show on a locked phone.
Verify safety numbers. Open a chat -> contact name -> View Safety Number. Then scan the QR code together (easiest when first setting up the chat with the other person). You can compare the number visually or audibly as well. This is the single most-skipped, highest-value step for higher-risk users.
Moving a group. There is no WhatsApp-to-Signal group migration — a Signal invite link creates or joins a Signal group, and no WhatsApp members or history come across. Start a fresh Signal group and invite people to it. You should know that anyone can forward the invite link to anyone because an invite link lets anyone holding it join. Remember that group members can see each other so you should share the link privately, revoke it after the move, and set number-privacy first. This reduces the risk of the member list being exposed.
Clean up. After moving, disable and delete WhatsApp cloud backups and old chats, or the shared history lingers in plaintext.
It would be nice if there was an interoperable standard to help you move from one app, like WhatsApp, to another, but that isn’t really a thing. Basically, you and your group will be starting fresh on Signal. You can “Export chat” from WhatsApp, but only on a per-chat basis. You can do a Chat backup in WhatsApp (Settings -> Chats -> Chat Backup) If you have used WhatsApp cloud backup without opting in to encrypted backups, then each person in the group who has opted for that becomes a possible point of exposure.
If a menu has moved since this was written, Signal’s own help pages are the authoritative, always-current reference.
Check it worked
Send a disappearing message to someone and watch it vanish on both ends.
Verify a safety number with a friend. A clean match means no interception of the keys used to encrypt the conversation between you. You can only do this check if the other person or device is handy.
Confirm Who can find me by number = Nobody. Ask a friend to try to find you by number (they can’t) and then by username (they can).
Once you have set this up, you will have significantly increased the privacy and confidentiality of your group.
Going further
If you have reason to believe that you are at higher risk (an investigative reporter, for example), consider the following:
Register with a secondary number (VoIP/second SIM), so your real number isn’t the account identifier. I’ll have more to say about this later in the series.
Only use your username - hide your number completely. By the way, don’t pick a username that you use elsewhere (the way that I use privacycdn, for example) if you want anonymity.
Verify your safety numbers with every important contact, not just one.
Turn on screen lock/screen security in Signal privacy settings.
Final thoughts
Everyone is on WhatsApp; Signal will only work if your contacts move. They can stay on WhatsApp for other groups and friends, but if they don’t want to move, for whatever reason, it could shrink your group. Alternatively, being on a secure platform may attract new members. Your mileage will vary.
You don’t have to abandon WhatsApp on day one; move the sensitive conversations (organising, anything that would harm someone if exposed) to Signal first, and let the rest follow.
What Signal does NOT do?
No protection is perfect. If your phone falls into someone else’s hands who can open the phone, if one of your group members takes screenshots, or if someone hacks your phone, information you thought private may leak or be shared. I’ll be talking about knowing your rights and crossing borders in forthcoming recipes.
Signal still requires a phone number to register (the number is the identifier, even if hidden).
Signal doesn’t hide that you use Signal from someone who has your number and checks.
Signal can’t stop the person you’re talking to from screenshotting, forwarding, or being compromised.
The Signal chat metadata available is minimal but not nothing — Signal knows the account exists, its creation date, and last-connection date.
Signal is a US-based nonprofit (Signal Foundation); but since it retains almost nothing, jurisdiction matters little in practice.
The flip side of holding so little: if Signal were ever subpoenaed, about all it could hand a court is your phone number, your account-creation date, and your last-connection date — nothing else.
No recipe here is a guarantee. It makes it more difficult to watch you, but it doesn’t make you invisible. It won’t stop a determined, well-resourced adversary. Weigh your own risks, and see the introduction for the full picture.
Researched and copy-edited with AI assistance; the writing is mine.