Signal Private Messenger, an encrypted messaging app, has made a notable feature upgrade that surpasses WhatsApp, at least in numbers.

Thanks to a new in-house developed service, Signal now allows up to 40 people to participate in an end-to-end encrypted group video call, compared to WhatsApp's maximum of eight.

"We built our own open source Signal Calling Service to do this job because there is no off-the-shelf software that allows us to support calls of that size while ensuring that all communications are encrypted end-to-end." Signal's Peter Thatcher wrote in a company blog post yesterday (December 15).

The rest of Thatcher's post goes into technical details, which we omit here. (Since Signal is an open source project, the code for the Signal Calling Service is available on GitHub for anyone to use.)

However, as Android Police's Manuel Vonau points out, when it added group video calling a year ago, Signal could only support five participants.

This is because the Facebook-owned (pardon the pun) Meta-owned service can only handle eight end-to-end encrypted video call participants at a time; Telegram can currently only handle up to 30 participants, but is gradually rolling out end-to-end unencrypted group video calls.

In other words, the transmission of the video call is encrypted between each participant and Telegram's servers, but Telegram can still see what is going on.

WhatsApp and Signal, on the other hand, cannot see the content of the call.

If you don't mind the possibility that your hosting service can see what you say online, and if you can provide the recording to the authorities if warranted, Telegram is a good choice, given the many other features it offers. But if you don't want anyone to know, then Signal or WhatsApp would be the way to go.

For more information, check out our list of the best encrypted message apps.