Real-time Steganography Utilizing RTP

"Real-time Steganography with RTP" at DEFCON 15 in Las Vegas, Nevada.

Real-time Transfer Protocol (RTP) is used almost ubiquitously by Voice over IP technologies to provide an audio channel for calls. As such, it provides ample opportunity for creation of a covert communications channel due to it's very nature and use in implementation. While use of steganographic techniques with various audio cover-mediums has been extensively researched, most applications of such have been limited to audio cover-medium of a static nature such as WAV or MP3 file audio data. This presentation details common techniques for use of steganography with audio data cover-medium, outlines the problem issues that arise when attempting to use these techniques to establish a full-duplex communications channel using audio data transmitted via an unreliable streaming protocol, and finally documents solutions to these problems as well as a reference implementation entitled SteganRTP.