Hiding Messages In VoIP Packets 83
Orome1 writes "A group of researchers from the Warsaw University of Technology have devised a relatively simple way of hiding information within VoIP packets exchanged during a phone conversation. The called the method TranSteg, and they have proved its effectiveness by creating a proof-of-concept implementation that allowed them to send 2.2MB (in each direction) during a 9-minute call. IP telephony allows users to make phone calls through data networks that use an IP protocol. The actual conversation consists of two audio streams, and the Real-Time Transport Protocol (RTP) is used to transport the voice data required for the communication to succeed. But, RTP can transport different kinds of data, and the TranSteg method takes advantage of this fact."
Re:A sad necessity (Score:3, Informative)
Last I heard it was done using slight timeframe modifications, one part of a movie playing slightly faster / slower with a pattern of fluctuations, not noticeable to somebody watching the movie, but measurable in a recording regardless of the quality of that recording.
Different segments for different theatres, with some overlap, not immediately obvious, and causes havoc if trying to digitally combine the output, especially if you're dealing with non-digital projection in the first place which is going to add it's own layer of imperfection.
It's surprisingly effective
Re:I dub thee... (Score:5, Informative)
The point is to hide from an eavesdropper that data is being exchanged. That's what the "Steg" in "TranSteg" stands for (Steganography).