Run a Google search on "Skype encryption," and chances are the first hit you'll get is a link to Skype's encryption assurance.
That's the one that says this:
All Skype-to-Skype voice, video, and instant message conversations are encrypted. This protects you from potential eavesdropping by malicious users.
It certainly sounds like your Skype communications are safe from prying eyes and ears, doesn't it?
Well, maybe not, actually.
According to Dan Goodin of
Ars Technica, the Microsoft-owned Skype "regularly scans message contents for signs of fraud, and company managers may log the results indefinitely. … And this can only happen if Microsoft can convert the messages into human-readable form at will."
Ars found this out by getting an independent privacy and security researcher, Ashkan Soltani, to work with them to cook up four links created solely for the purposes of the article.
Two of those links weren't clicked on, while the other two - one an HTTP link and the other an HTTPS link - were accessed by a machine at 65.52.100.214, which is an IP address that belongs to Microsoft.
Plenty of people were curious to know what would happen, post-Microsoft acquisition, to Skype's years-long reticence about allowing back doors to enable surveillance.
Read more: http://nakedsecurity.sophos.com/2013/05/22/microsofts-reading-skype-messages/