Signal has made encryption available to the masses, but the secure messaging service also leaves one bit of personal information exposed: Your private phone number.

In the show I'm in right now, there's an scene when the less-than-pleasant Archdeacon of the Notre Dame Cathedral, Claude Frollo, tells his adopted son, Quasimodo, that "it takes two people to communicate." But it's not just the hunchback that forgets this lesson — I'm surprised, but not that surprised, about how easy it is to ignore this fact in everyday life.

When it comes to messaging apps, Signal is one of the most secure options around, but it turns out the service actually has a pretty big vulnerability if you're using it on a Mac.

Skype is one of the most popular messaging apps around, but it's never offered the type of end-to-end encryption that's become standard in other services such as WhatsApp and iMessage.

So, you're interested in secure, encrypted chat apps. You have a few different choices, but as with any chat app, what all your friends are using is important. To that end, Signal and WhatsApp are easily the most popular. Here's how they compare.

Facebook's Messenger instant messaging platform is now widely used by people, and even businesses, as a communication tool. Many users are uninhibited when they chat on Messenger and talk about sensitive topics with family and friends. Facebook wants to ensure these conversations remain absolutely private. The social media organisation has started testing out a new Secret Conversation function that uses technology developed by Open Whisper Systems, the company that created the renowned secure messaging app Signal. Here's what you need to know.

For those who are serious about privacy, you would be familiar with messaging services that use end-to-end encryption. Signal is the one that is favoured by privacy activist Edward Snowden but unlike many popular messaging services like Facebook Messenger and WhatsApp, it didn't support desktop use. We have some good news. Signal Desktop has come out of beta and is now publicly available. Here's are the details.