But a few years ago, sending encrypted messages was a challenge. Just to get started, yous had to spend hours following along with jargon-filled tutorials, or be lucky enough to detect a nerd friend to teach y'all. The few that survived this process quickly hitting a second barrier: They could only encrypt with others who had already jumped through the aforementioned hoops. So even later on someone finally set up encrypted email, they couldn't use information technology with most of the people they wanted to send encrypted emails to.

The situation is much better today. A number of popular apps take come along that make encryption as easy as texting. Among the most secure is Signal, open up-source software for iOS and Android that has caught on among activists, journalists, and others who practise sensitive work. And probably the near pop is WhatsApp, a Facebook-owned platform with encryption setup derived from Point. For me, the spread of encrypted chat apps means that, with very few exceptions, all of my text messages — with friends, family unit, or for piece of work — are end-to-terminate encrypted, and no ane even has to empathise what a "public key" is.

Simply there is a major issue with both Signal and WhatsApp: Your account is tied to your phone number.

This makes these apps actually easy to utilise, since at that place are no usernames or passwords to bargain with. It also makes information technology piece of cake to discover other app users; if someone is a contact in your phone and has the app installed, you can send them encrypted texts with no further attempt.

Merely it too means that if you desire people to be able to send y'all messages securely, you need to hand out your phone number. This puts people who collaborate with the public in an bad-mannered bind: Is the ability for strangers to contact yous securely worth publishing your private telephone number?

In this article I explain how to create a 2d Point number that is safe to publish on your Twitter bio and business concern cards, and then strangers have an easy way to contact you securely, while your principal phone number remains individual. I explain how to obtain a second phone number, how to register it with the Bespeak server, and how to configure information technology to use Indicate Desktop — fifty-fifty if you're already using Signal Desktop with your individual phone number. I volition focus on Betoken rather than WhatsApp for reasons I'll explain farther down (basically, WhatsApp appears to block not-cellular phone numbers that make all this possible with Bespeak).

Why Wouldn't Yous Want to Publish Your Telephone Number?

When you give out your telephone number, y'all risk opening yourself up to corruption. Equally freedom of expression activist Jillian York wrote on her personal blog, "Every bit a woman, handing out my phone number to a stranger creates a moderate risk: What if he calls me in the middle of the nighttime? What if he harasses me over SMS? What if I have to alter my number to get away from him?"

If y'all're a public figure, and peculiarly if y'all're a women or person of color, you're probably used to sexist or racist jerks yelling slurs and threats at you on Twitter, Facebook, and in the comments department under the articles you write. Publishing your private phone number could make this problem worse and could make these people harder to mute.

It could also open your online accounts to assail. Last year, someone hacked racial justice activist DeRay Mckesson's Twitter and email accounts by taking over his phone number. The hacker chosen Verizon and, impersonating Mckesson, asked to change the SIM card associated with his phone number to a new one that they controlled, so they could receive SMS messages sent to his phone number.

Having a unique public number just for Point could mitigate this sort of attack; it's harder for a hacker to hijack the number that'due south tied to your Twitter and e-mail accounts if they don't know it in the first place.

(If an attacker takes command of your phone number, like they did with Mckesson, they could besides take over your Signal account. If someone did this to your friend, you'd see a "safety number changed" alarm in Signal — the same bulletin you run into when a friend gets a new phone. If you ignore this alarm and text them anyhow, you lot'll actually be texting the assaulter. You tin verify safe numbers to ostend that your Signal app is encrypting messages to your friend'south phone, and not to some attacker's phone.)

How to Obtain a Second Phone Number

When yous open the Point app for the first time and blazon in your phone number, hither's what happens:

  • The Signal service tries sending an SMS message with a verification lawmaking to your telephone number. If you can receive that bulletin or the app can receive it directly, and the message contains the correct lawmaking, then the app successfully registers the account.
  • If you tin't receive the verification message, Signal gives you lot the option to attempt a vocalism call instead. In this case, the Signal service tries calling your phone number. When you answer, a robot voice tells you lot a verification code, and yous tin can type information technology into the app. If y'all type the correct code, the app registers the business relationship.

The initial step of verifying a telephone number is the only step in which the phone network is involved. After this, Signal uses the internet for everything. Your telephone number is only used as a way to identify your Betoken account (basically, it's your username), and your phone company doesn't take access to any data about anything that goes on in Signal.

This ways that, as long as you have admission to a phone number where you can answer voice calls, like a landline or a VoIP number, yous can use that phone number with Point. (This isn't true for all services. WhatsApp seems to simply let you to register using telephone numbers distributed by cellphone carriers — but I've heard mixed reports, and so it doesn't hurt to try.)

In club to go on, you need to obtain a 2d phone number that you're OK with publishing. This tin be:

  • The desk phone at your role.
  • A gratis Google Vocalism phone number, if you lot live in the United states of america (this is what I do).
  • Any telephone number from whatever online calling service, similar Skype.
  • A inexpensive pre-paid SIM carte du jour for a few dollars a calendar month (and temporarily put it on your phone to register your second Signal number).
  • Twilio, a cloud service that allows developers to write software that makes and receives phone calls and SMS letters. If following these instructions isn't besides daunting, you can purchase phone numbers for $1/calendar month from Twilio to apply for Signal. Encounter this similar guide, written by Martin Shelton, for more thorough instructions on using Twilio for your 2nd phone number.

Information technology'southward important to maintain control of this phone number. For example, you lot could use a disposable SMS service to annals with Signal — there are many such services if yous search for them — but those phone numbers tin can exist used by anyone. Similarly, yous should avoid using a public payphone's number, or a SIM card on which you do not intend to renew service. If someone else can receive SMS messages or telephone calls to this telephone number, they tin can take your Indicate account away from you lot.

If you have tips for other ways to obtain permanent phone numbers, post them in the comments.

Picking a Device for Your Second Signal Number

In order to register your second phone number with Signal, yous're going to need a defended device for it — or at least a defended user account on a device. The device doesn't demand to have any phone service, and it doesn't even technically need to exist a telephone. Here are your options.

If you lot're an Android user, you're in luck. You likely take never used this characteristic, only Android supports multiple user accounts on a unmarried device. Each user business relationship has its ain gear up of apps and app data. Y'all can create a second user account on your device specifically for your 2nd Signal number.

Open the Settings app, select Users, and select "Add together user or profile" to add a new user. After creating a new user, log in to it and install the Signal app. Don't forget to gear up screen lock for the new user — otherwise, anyone with physical access to your telephone volition be able to hands access the Signal messages in your second user, even if your main user account is locked.

To switch between users on your phone, drag the notification bar down and tap on the user icon.

If you're an iPhone user, and you're already using Signal with your private phone number, setting up your public Bespeak business relationship is a scrap more than complicated. Unfortunately, there's no fashion to set up 2 separate Signal phone numbers on the same iPhone.

The simplest way to keep is to find a separate iOS or Android device and employ that for the second number. This device doesn't need telephone service or a SIM card. Information technology could be an erstwhile iPhone or Android telephone you don't use anymore, or an iPad, iPod Touch, or Android tablet.

You can also elect to use your new public phone number only with Signal Desktop. Doing this involves removing your private Betoken business relationship from your iPhone, setting upward the public account and Signal Desktop, and and then restoring the private account, which will generate a warning to your contacts that your rubber number has changed. It likewise significantly limits the ways you lot can utilise Signal, equally I outline below.

For the truly geeky, it's too possible to utilise your estimator to register the second Bespeak number, simply only go this route if yous're the type of computer nerd who enjoys troubleshooting tricky bug. You tin use a command-line tool called signal-cli to register your phone number with Point service, or you can install android-x86 inside a virtual machine and utilise that every bit a virtual Android device for Signal. If that seems like a chip much, you're better off tracking down an quondam smartphone instead.

Registering Your New Number With Signal

Now that yous take a 2nd phone number and a device picked out, information technology's time to register it with Bespeak. I'thousand using an Android device in the following photos, but the process in iOS is like.

On your second Signal device (or the 2nd user of your Android telephone), open the Bespeak app for the first time. Blazon in the phone number you've obtained to use equally your public Bespeak number (don't type in your private phone number!), and annals the phone number.

Register with Indicate using the second phone number yous obtained.

The Signal service will then send this telephone number an SMS message. But, since this device isn't really associated with this phone number, it will neglect. At least on Android, y'all must wait the full two minutes for it to fail. (If yous're on iOS and able to receive your verification code over SMS, for example in the Google Phonation app, enter the lawmaking into Point, and skip downwards to the next section, "Setting up Signal Desktop.")

Look two minutes for SMS verification to fail.

At present that SMS verification has failed, you accept the option to do vocalization verification. Brand sure you lot're in a position to answer your second phone number. If this is a landline, go stand up next to the phone; if this is a Google Vocalisation number, make sure yous have Google Voice open in a browser tab, or the Google Voice correctly configured, etc.

Verify with the Signal service using a voice call instead.

Finally, tap "Phone call Me." When your 2d telephone number rings, answer it. You should hear a robot vox saying, "Your Signal verification code is" followed past a six-digit number. Type this number into the box in Bespeak and tap "Verify."

If all goes well, the verification process volition succeed, and your new phone number will be registered with the Bespeak service.

And that'southward it! This device tin can now receive messages to your second Bespeak phone number. You tin tell everyone they can contact you using Signal with this phone number, and the text letters will finish upwards going to this device.

But now you lot too have to deal with checking two divide devices for your letters (or ii separate users on ane Android device). To make things a bit more usable, you might desire to set upwardly Signal Desktop.

Setting upwardly Indicate Desktop

The desktop version of Indicate is a Google Chrome app, which means that yous install it inside of your browser (this volition exist changing soon, more on that below). You tin read more nearly Signal Desktop here, including some security considerations on whether you should employ the desktop version.

If you'd similar to employ Bespeak Desktop with only one of your phone numbers, this is simple. For case, maybe y'all'll but employ Signal on your phone for your personal number, simply you'll use Signal Desktop for your second, public Signal number. In this case, just install Point Desktop from the Chrome Web Store, and follow the instructions to configure it using the Signal device of your option.

If you'd like to use Signal Desktop with both phone numbers, y'all demand to gear up separate Chrome profiles (or "People"). Most Chrome users only have their default contour — this stores browser history, bookmarks, Chrome apps, and other settings. But it's possible to create new profiles and easily switch between them. You lot can prepare Signal Desktop in your default profile for your private telephone number and create a 2d Chrome contour specifically for your second Signal number.

Signal developers are currently switching up how Betoken Desktop works. Soon it will be a standalone app, no longer through Chrome. This means that you won't be able to run two copies at the same time by creating two unlike Chrome profiles. Only, for the time beingness, the following instructions nonetheless work fine.

First, let'south set up Signal Desktop for your personal telephone number in your default Chrome profile (if you already apply Indicate Desktop, skip the next few paragraphs). Open up Chrome and get here to install Signal Desktop. Later on it's installed, a welcome screen will pop up explaining that you need to install Signal on your telephone first, and showing you lot a QR code to scan from your phone, similar this:

Follow the instructions using Signal on your personal cellphone to link it to this Signal Desktop.

Yous probably besides want to brand sure that this Signal Desktop is piece of cake to open up. If you're using a Mac, right-click on the dock icon, select Options, and check "Go along in Dock." If you lot're using Windows, right-click on the taskbar icon and select "Pin to taskbar."

Now it's time to create a new Chrome profile for your second Signal telephone number. Kickoff by opening the Chrome menu (the icon in the top-correct of your browser with iii dots) and cull Settings. Under People at the top, click "Manage other people."

In the lesser-right, click "Add person." Come upwardly with a proper noun and an icon for this Chrome profile. In this screenshot, I'm calling my new person "Betoken for strangers" and giving it a ninja avatar.

Later clicking the save button, a whole new Chrome window opens with "Bespeak for strangers" in the top-right corner. (Note that you can click the name of your profile in the top-right to switch to other profiles.)

Like y'all did with your other contour, go here and install Signal Desktop. Again, a fresh new welcome window will popular up giving you instructions to get started, once again with a QR code.

Follow the instructions, just this time, utilise your device for your second Signal number (or the second Android user, if you're doing it all on one Android phone). When you're done, you'll take successfully linked your second Signal phone number to your second Point Desktop!

You should make sure that this Signal Desktop is easy to open equally well. If you lot're using Mac, right-click on the second Signal dock icon, select Options, and check "Go along in Dock." If you're using Windows, right-click on the second Signal taskbar icon and select "Pin to taskbar."

Now yous should take ii carve up Indicate Desktop icons, one for your private telephone number and the other for the second phone number you only set up. You can also hold the mouse over the different Signal icons to tell them apart.

Finally, hither's a tip for running multiple Betoken Desktops on the same computer. Within Signal Desktop, click the three dots menu icon and choose Settings. This allows you to choose between iii unlike themes. Make sure that your 2 unlike Signal Desktop windows have different themes to make them easier to tell apart.

(For the few of you who run the Qubes operating system, this process is much simpler. Only install Indicate Desktop in carve up AppVMs for each telephone number. This is what I do.)

Using Signal Desktop as Your Main Betoken App

At present that your public Indicate number is safe to publish, and encrypted texts go directly to your desktop, it might be tempting to only use the desktop app for this phone number. This is fine, but you should be aware of its limitations.

Indicate Desktop app has fewer features than the mobile app. You tin can't accept encrypted vocalization or video calls in Betoken Desktop, and y'all likewise can't create or modify Point groups — if you need to exercise these things, you have to do them on the mobile device. And while disappearing messages work fine, in that location's no interface to delete individual messages from the desktop app.

Another Bespeak Desktop limitation is that at that place'southward no mode to assign names to Signal contacts from there; Signal relies on your phone'south contacts to interpret phone numbers into names. So if you'd like to assign a name to a contact, y'all have to add them as a contact on the mobile device that you registered this Indicate number with outset.

Finally, messages that make it to Signal Desktop, merely not to the phone used to gear up up Bespeak Desktop, will accumulate on the server. Here's why: When someone sends you a Signal message, their Signal app encrypts the message and sends it to the server. The server stores this encrypted bulletin until it tin be successfully delivered to your devices, then the server deletes its copy afterwards. But since your Signal account is associated with 2 devices, the mobile app and the desktop app, the server won't delete its copy of the encrypted message until it successfully delivers the bulletin to both devices. Therefore, it's important to periodically power on your mobile device that you configured Signal on, even if you intend to primarily just use the desktop app.

Will Signal E'er Make This Simpler?

At the moment, y'all can only register a Point account using a telephone number, but a future version of Signal could support other identifiers every bit well, such as email addresses.

Just like with telephone numbers, Bespeak could automatically verify electronic mail addresses. And similar with phone numbers, people shop email addresses in their telephone'southward contacts, and so contact discovery could still be automatic. Unlike private telephone numbers though, journalists and activists routinely publish their email addresses for strangers to contact them. And for those who wish to apply Bespeak anonymously, like whistleblowers, it'southward much simpler to obtain an bearding electronic mail accost than an anonymous phone number.

This feature has been widely requested past users, and the associated issue is still open up on GitHub, where you can find Bespeak's source code. Just will Signal's developers implement it? I asked, and they told me that they don't annotate on new features until they've shipped them.

If you take any feedback nearly this tutorial, please mail it on the comments, or contact me on Signal at (415) 964-1601.