The Register has news of research into creating a finger print of a voice call that could potentially help prove its authenticity. This reminds me very strongly of the story I wrote up from a while back of security researchers using audio artifacts introduced by power transmission lines for similar purposes.
The tool is called PinDr0p, and works by analysing the various characteristic noise artifacts left in audio by the different types of voice network – cellular, VoIP etc. For instance, packet loss leaves tiny gaps in audio signals, too brief for the human ear to detect, but quite perceptible to the PinDr0p algorithms. Vishers and others wishing to avoid giving away the origin of a call will often route a call through multiple different network types.
The research is out of the Georgia Institute of Technology, not the metro police lab out of Penge, South London. The Register doesn’t mention any link between the two projects. They seem so similar that either this kind of fingerprinting is obvious with the right kind of gear or there is an uncredited connection.
I see this as further evidence that there are plenty of aspects of new technologies that offer investigative toe holds lessening the need for legislating fixtures like under CALEA and the recently announced internet wiretapping effort to introduce similar legislation next year.
Voice-routing call fingerprint system fights ‘vishing’, The Register