Skype, the peer-to-peer communications software now controlled by software giant Microsoft, has been quietly re-architected in a move that will enable US government agencies to tap people's Skype communications.
It follows the emergence of new legislation in both the US and Australia that would require makers of online communication software to build-in backdoors so that government agencies can more easily listen-in on, or read, people's online communications.
Skype's service connects users via 'supernodes'. These are servers that both caller and recipient connect to in order to be able to talk to each other, while the communications are encrypted using the 256-bit encryption based on the Rijndael advanced encryption standard.
In the past, anyone running Skype on their standard PC could be elevated to supernode status, should they be logged in long enough. And, as the communications were peer-to-peer, Skype claimed that it was impossible for law enforcement agencies to serve it with a warrant to enable wiretapping.
Now, however, Skype calls are routed via servers based in the US, owned and controlled by Microsoft, and, as the company issues the encryption keys, it could easily decrypt the traffic too.
Being based in the US would also make it subject to US law enforcement and warrants issued by US courts.
Microsoft's silence on the issue also raises question marks over its Skydrive and other cloud storage services, and the privacy and security that they offer.
In the past, law enforcement agencies have complained that they were unable to eavesdrop on Skype. German police even hired a company to develop Trojans that could record suspects' communications on their own PCs or laptops. In 2009, the US National Security Agency reportedly offered a reward for anyone that could devise a means of eavesdropping on Skype.
Microsoft has refused to comment on claims that it re-architected the software in a manner that enables the interception of communications. It has claimed that the changes were purely the result of a software upgrade.
But in June 2011, just a month after its Skype acquisition, Microsoft was granted a patent for what it described as 'legal intercept technology'. That patent described a way of intercepting voice-over-IP services, such as Skype, to "silently copy communication transmitted via the communication session", according to the patent filing.
That patent had been filed on 23 December 2009.
[Turn to next page]