Signal Iran block workaround released as secure messaging app calls for help

Signal is adding a new way for those blocked from using the private messaging platform to connect, a workaround particularly for those in Iran who have found the service censored. News broke in late January that Signal had been targeted by the Iranian government and placed on its internet block list, after the app hit the number one spot for downloads in the country.

"Unable to stop registration, the [Iranian] censors are now dropping all Signal traffic," the company said at the time. "Iranian people deserve privacy. We haven't given up."

Now, it's revealing just how it plans to do that, at least for the moment. "As an interim solution to help people in Iran get connected again, we've added support in Signal for a simple TLS proxy that is easy to set up, can be used to bypass the network block, and will securely route traffic to the Signal service," Signal said today.

Even with the proxy, the core tenets of Signal remain in place. Conversations are end-to-end encrypted still, which has always been the platform's big boast. However traffic also is opaque to the operator of the proxy itself.

That's important, as Signal is counting on other users from setting up and running those proxies. The process is simple, the company says, and requires just a server with ports 80 and 443 available, plus a domain or subdomain that points to that server's IP address. "The proxy is extremely lightweight," Signal explains. "An inexpensive and tiny VPS can easily handle hundreds of concurrent users."

The new connection method has already been added to the latest Signal beta for Android. In a few days time, meanwhile, it'll be rolled out to the production version of the app. Users will be able to manually configure it with a proxy server's settings, or automatically do that when the user taps a link in another app.

"We hope that organizations and individuals will step up to run Signal TLS Proxy servers for Iranian users and help coordinate their distribution," Signal said today. "We're also continuing to investigate other techniques that are more automated and convenient."

The Iranian block came after a filtering committee focused on identifying "criminal content" took issue with Signal's support for encrypted conversations. It's not the first time that has happened, Al Jazeera reports, with sporadic blocks applied in 2016 and 2017. However, since then Signal has risen significantly in profile.

That particularly came in the aftermath of widely-reported WhatsApp changes, as users looked to alternative messaging platforms over fears that their conversation data would be shared with Facebook. WhatsApp attempted to set that belief straight, but not before Signal and other platforms like Telegram saw a huge – and in some cases system-crashing – influx of new users.