They can only send emoticons, files, and audio messages from the chat window.
Microsoft has partnered with encrypted messaging app Signal to encrypt messages on Skype. What this means is that Skype's end-to-end encryption is not a complete one; but kudos to Microsoft for adding it in the first place.
It is important to note that no chat content from these conversations will be displayed in the chat list, or with other notifications - in order to keep any shared information private.
If Microsoft gives the go-ahead and E2E support lands in the Skype stable release, all of today's major IM platforms will be supporting encrypted conversations as optional, non-default features.
Thursday's Hangout With Steven Mnuchin and Sarah Huckabee Sanders
White House press secretary Sanders defended the decision in recent weeks, saying it has been in the works for the past six months.
We're looking to you, Skype Insiders, to tell us if this new feature works as expected before enabling it for everyone. For now, all of these conversations must be one-to-one, as no group messages are allowed. This is the same end-to-end encryption protocol used by Facebook for WhatsApp and Facebook Messenger, and by Google for the Allo app. Skype on the other hand, has always been criticized for not being safe and willing to share your sensitive information with authorities if the need arises. You can only participate in a private conversation from a single device at a time.
Interested in encrypted communications but not Skype? A separate invite must be sent to switch over to another device.
Private Conversation capabilities are limited. You will be taken to a new chat with them.
To make matters worse there were also reports that Skype had been running an internal team, codenamed Project Chess, that was tasked with making it easier for the Feds to not only collect metadata, but also to listen in on calls and conversations. Those who really want secure communications should probably just cut out the middleman, and install Signal's app.