Microsoft has promised to bring end-to-end encryption to its Skype messaging service via a partnership with Open Whisper Systems.
The new feature will be called Skype Private Conversations and will encrypt audio calls and text conversations, along with images, audio and video files sent via the service.
Microsoft will be using the Open Whisper Systems's open-source Signal Protocol to encrypt these communications. This is the same protocol used by Facebook for WhatsApp and Facebook Messenger, by Google for the Allo app and for the Edward Snowden-approved Signal Private Messenger.
"At Signal, our goal is to make private communication simple and ubiquitous.
"With hundreds of millions of active users, Skype is one of the most popular applications in the world, and we're excited that Private Conversations in Skype will allow more users to take advantage of Signal Protocol's strong encryption properties for secure communication," Signal said in a blog post announcing the partnership.
Skype Private Conversations is available now for Insider testing, and you can test it by downloading and installing Skype Insider version 220.127.116.11 for Android, iOS, Linux, Mac, and Windows.
Ellen Kilbourne, manager of the Skype Insider Program, explained: "Give it a try by selecting 'New Private Conversation' from the compose menu or from the recipient's profile. After the recipient accepts your invite, all calls and messages in that conversation will be encrypted end-to-end until you choose to end it.
It's worth noting, however, that end-to-end encryption will only work if you're talking to another person also using a Skype Insider app, and encrypted video calls and group chats are not yet supported.
Private Conversations also won't synchronise across devices, which means if you start an encrypted chat with a contact on your phone, you won't see it logged on your computer.
Microsoft plans a full rollout of Skype Private Conversations later this year.
Wikileaks Vault 7 suspect Joshua Schulte fingered by FBI after re-using smartphone passwords on his PCs
Joshua Schulte indicted on 13 counts relating to Vault 7 leaks and trading in images of child abuse
Alexa for Hospitality will link with existing systems so guests can order room service and control the air con
Massive volcanic eruptions could have warmed Mars' surface sufficiently for oceans to form
Examination of fruit flies' brains generated more than one billion data points for scientists to analyse