Introducing Signal PINs

Signal on 19 May 2020

An illustration of asterisks superimposed over the shape of a smartphone.

At Signal, our goal is to build a reliable, secure, and private communication experience that is broadly accessible and simple to use. From the beginning, we’ve designed Signal so that your information is in your hands rather than ours.

Currently, that also happens to mean that if your hands accidentally lose your phone to the toilet, your information in Signal is lost along with it.

That could be more information than you’d initially consider. We think private communication means much more than just encrypted messaging, and we’ve designed Signal accordingly. Signal provides private groups, private contact discovery, private profiles, etc. All things that are exclusively in your hands. As we move to support additional features the Signal community has asked for – like addressing that isn’t based on phone numbers and chatting with contacts that aren’t saved in an address book – it means that more and more of this important supporting data can also be lost.

Other apps and platforms – even if they support some form of encrypted messaging – store this kind of data in plaintext on their servers, so that when you lose or switch phones this information isn’t lost along with it. That’s not good for your privacy, though, so we took a different approach that doesn’t sacrifice the privacy and security you expect from Signal.

In the latest version of our apps, we’re introducing Signal PINs. Signal PINs are based on Secure Value Recovery, which we previewed in December, to allow supporting data like your profile, settings, and who you’ve blocked to be securely recovered should you lose or switch devices. PINs will also help facilitate new features like addressing that isn’t based exclusively on phone numbers, since the system address book will no longer be a viable way to maintain your network of contacts.

Signal PINs are at least 4 digits, but they can also be longer or alphanumeric if you prefer. Because Signal doesn’t have access to your keys – or your data – your PIN isn’t recoverable if you forget it, so our apps help you remember your PIN with periodic reminders. Don’t worry, these reminders get less frequent over time.

We’re excited to get Signal PINs in your hands, as we think this technology will help us deliver a number of new, useful, and improved features while maintaining strong privacy and security.