Proxy Please: Help People Connect to Signal

Meredith Whittaker on 09 Aug 2024

Several countries have recently blocked Signal, leaving their residents without a trusted and safe place to communicate.

To help in this situation, Signal provides a built-in censorship circumvention feature and also includes support for a simple TLS proxy that can bypass these blocks in many circumstances and let people communicate privately.

  • To enable Signal’s built-in censorship circumvention feature, go to Signal Settings > Privacy > Advanced > Censorship circumvention.
  • Signal’s simple TLS proxy is supported on both Signal Android and Signal iOS and can also work to bypass network blocks and securely route traffic to the Signal service. Anyone can set up a proxy, and once it’s deployed you will be able to provide a URL for people to start using it. Simply tap the URL on your device to get Signal connected to the proxy.

Please help if you can: To help make our circumvention efforts as effective as possible, we invite those who are willing and able to set up their own proxy servers to do so by following the instructions here.

This isn’t the first time this has happened. We’ve shared information about running proxies before, first in 2021 and then again in 2022, and each time the extended community pitched in to hugely extend our coverage. We’re grateful for their generosity and dedication, both then and now. Our hope is that this will help people access Signal in spite of government blocking while we explore additional techniques to ensure that Signal is available to anyone who wants or needs to use it.

Be the proxy

If you would like to run a proxy server, you can follow the updated setup instructions here.

The Signal Android and Signal iOS apps are registered to handle links from the signal.tube domain so they can automatically configure proxy support when you tap on a link from any other app. You can also manually configure proxy information in your Signal Settings too:

  • Android: Signal Settings > Data and storage > Proxy > Use proxy
  • iOS: Signal Settings > Privacy > Advanced > Proxy > Use Proxy

Unlike a standard HTTP proxy, connections to the Signal TLS Proxy look just like regular encrypted web traffic. There’s no CONNECT method in a plaintext request to reveal to censors that a proxy is being used. Valid TLS certificates are also provisioned for every proxy server, making it more difficult for censors to fingerprint the traffic than it would be if static self-signed certificates were used instead. In short, everything is designed to blend into the background as much as possible.

The Signal client establishes a normal TLS connection with the proxy, and the proxy simply forwards any bytes it receives to the actual Signal service. Any non-Signal traffic is blocked. Additionally, the Signal client still negotiates its standard TLS connection with the Signal endpoints through the tunnel.

This means that in addition to the end-to-end encryption that protects everything in Signal, all traffic remains opaque to the proxy operator.

Spread the word: Use the hashtag #SignalProxy

If you set up a Signal proxy, you’ll need to get the word out so that people can use it. Use the hashtag #SignalProxy to make it easy to find on the social platforms of your choice.

When you publicly post a signal.tube link, or if a particular server becomes too popular, it increases the chance that censors will add those IP addresses to their block lists.

A more discreet approach would be to announce publicly that you’ve created a Signal proxy and then offer to share connection details via DM or a non-public message. For example:

Reply to this thread if you want the connection details for my #SignalProxy, or send me a DM so I can share the link with you.

It’s easy to launch new proxies, and as long as there are servers in the world there is no limit to the number of Signal TLS proxies that people can run.

Shifting grounds

The world moves around us in unpredictable ways, and we will continue to do our best to keep Signal available for everyone who needs it, whenever they need it. Thank you for your support.