On information hiding in retransmissions

Abstract

The paper presents an idea and experimental results for RSTEG (Retransmission Steganography), which is an intra-protocol hybrid network steganography method. It is intended for a broad class of protocols that utilises retransmission mechanisms. RSTEG enables hidden communication by not acknowledging a successfully received packet in order to intentionally invoke retransmission. The retransmitted packet carries a steganogram instead of user data in the payload field. Experimental results for TCP-based RSTEG traffic analysis are enclosed which were focused on measuring steganographic bandwidth and influence on TCP network traffic in terms of undetectability. © 2011 The Author(s).