Q >> I’ve been reading about a government security planning meeting that took place via a program called Signal. Not great, but I’m most curious about whether Signal really has auto-expiring messages and how that works. Can you elucidate?

A >> The Signal snafu has definitely been top of page with news outlets around the world. I find it amazing to think that matters of state are discussed using tools similar to those my friends and I use to figure out where to eat dinner!

In an era of commercial social networks with valuations in the billions, Signal is also noteworthy because it’s owned by a non-profit foundation and accepts no advertising. You can’t buy stock but you can donate if you’re inspired.

Signal encrypts everything

Signal, available for Android, iPhones, and, with clients, Mac and Windows, is most similar to Facebook Messenger. It offers one-to-one text chats that can include photos and videos, stickers, emoji, etc. You can also jump onto a video call.

More to the point, it supports all the same features for group chats that can encompass dozens of people. Even video chats, just like Zoom, Microsoft Teams, and Google Meet.

Where Signal differs from the alternatives is that all communications are encrypted. Whether you’re sharing racy texts with your long-distance sweetheart or are on a live video call negotiating a questionable transaction, no-one can access your communication. This focus on privacy is why so many people are enamored of Signal in an era when everything else seems to be scanned, analyzed, and even fed to AI ‘bots behind the scenes.

Signal has disappearing chats

The other feature that makes Signal valuable when having a sensitive discussion is that you can set the lifetime of messages to anything you’d prefer. Want them to vanish after 60 seconds? Doable. Want to have them stick around until Dec. 31, 2025, at 11:59 p.m.? You can set that up too.

These “disappearing messages,” as Signal calls them, apply to one-on-one chats, texts, photos, and video, along with group chats and conversations.

By default communications do not disappear, however, so once people have joined, someone has to go into the group settings and select the duration of messages. Everyone else then sees a notification that “Dave set disappearing message time to 1 hour” or similar.

Back to the news

Getting back to the news story out of Washington, D.C., this means that everyone in the discussion saw a notification that one of them had set the disappearing message duration.

Remember, however, that even if you set it to 30 seconds there’s no way to guarantee that the person on the other end isn’t capturing what’s on their screen. If screen recording is blocked, they can always film their phone or computer screen with a different device, something that’s impossible to block.

It’s curiously reminiscent of the voice messages Mr. Phelps would get from the Impossible Mission Force that would “self-destruct in 60 seconds”.

Dave Taylor has been involved with the online world since the beginning of the Internet. He runs the popular AskDaveTaylor.com tech Q&A site and invites you to subscribe to his weekly email newsletter at AskDaveTaylor.com/subscribe/ You can also find his entertaining gadget reviews on YouTube at YouTube.com/AskDaveTaylor.