SkypeHide: Keeping Skype Confidential

Secret messages, covert channels and hidden information may sound like something from the Bourne Ultimatum film, but it is also part of an alleged new offering from Skype.

If Skype, which allows users to communicate via microphone, webcam, instant messaging and phone calls, goes ahead with the newfangled concept, this would allow the creation of a covert channel whereby two parties can make contact without a third party even realising the two are communicating.

The transmission of undetectable messages is able to happen through the art, or indeed the science, of steganography; a technique which involves embedding secret data.

In relation to SkypeHide, a steganography system for VoIP networks is being looked at by a Polish professor, Wojciech Mazurczyk, from the Warsaw University of Technology.

Mazurczyk is a specialist in this field and he and his team will present SkypeHide at a steganography conference in Montpellier, France, this coming June.

Mazurczyk analysed Skype data traffic during calls and found that when a silence is detected, 70-bit packets are sent, instead of the larger 130-bit packets that carry speech.

Although Skype does not do anything with the default silent packets that are sent, Mazurczyk and his team say they have found a way to exploit this system by inserting encrypted data into some of the silent packets. This means users could hide extra, non-chat messages during a call.

On Mazurczyk’s website he says digital watermarking and steganography protect information, conceal secrets or are used as core primitives in digital rights management schemes.

“Steganalysis and forensics pose important challenges to digital investigators and privacy techniques try to hide relational information such as the actors’ identities in anonymous communication systems,” Mazurczyk said.

“These and other topics share the notion that security is defined by the difficulty to make (or avoid) inference on certain properties of host data, which therefore has to be well understood and modelled.”

As well as this potential change for the Microsoft division, bosses have also just released an official date for the demise of Messenger.

On March 15 the global service will come to an end, except for mainland China where Messenger will continue to be available, and instead Skype, bringing together features of Messenger, will be used in its place.

Users will update to Skype and sign in using a Microsoft account/Messenger ID and all Messenger contacts will be carried over.

Users will be able to video call Messenger contacts and Facebook friends on Skype, collaborate with up to 10 people on a group video call (available with a premium account) and will have access to all the other usual Skype features.

[Image via techboom]