SkyDe: a Skype-based Steganographic Method

Abstract

This paper introduces SkyDe (Skype Hide), a new steganographic method that utilizes Skype encrypted packets with silence to provide the means for clandestine communication. It is possible to reuse packets that do not carry voice signals for steganographic purposes because Skype does not use any silence suppression mechanism. The method's proof-of-concept implementation and first experimental results are presented. They prove that the method is feasible and offers steganographic bandwidth as high as 2.8 kbps.

Broadcast Steganography

“…Adaptive, Standard 2 other domains that rely on covert communication [38,43]. For a military example, consider a camp where each soldier has an army smartphone, on which they receive weather forecast, unclassified news and other information in the clear.…”

Trends Toward Real-Time Network Data Steganography

“…The rapid rise of transmitting voice data over the Internet using voice over IP (VoIP) followed by the development and subsequent explosive use of the VoIP application, Skype, spurred much research into how to use these environments for covert communications [29][30]. VoIP is a stream-based communications protocol that uses the real-time protocol (RTP) to set up and control the data flow [29][30].…”

“…VoIP is a stream-based communications protocol that uses the real-time protocol (RTP) to set up and control the data flow [29][30]. An associated protocol, the real-time control protocol (RTCP) is used in conjunction with RTP to provide out-of-band statistics and control information for RTP sessions [12][13].…”

“…One described method of using this application protocol header for steganography is to merge the RTCP and RTP control information and embed unused bits in the IP, UDP, and RTP headers to signal various parameters that enable watermarking data in the voice stream. Another method, known as SkyDe, uses silence periods of a voice call to embedded encrypted steganography data and use the RTP and UDP headers to signal which packets are covert information [29] [30]. Each of these examples show that, like the more well-known storage-protocol and timingprotocols of IP and TCP, a much broader range of application-protocol header fields can be investigated for their potential toalso be used to establish covert communications.…”

SmartSteg: A New Android Based Steganography Application

“…The researchers method lies in how Skype manages silence sequences. The application encrypts the secret data and embeds it in a silence package when ones appear [3].…”