Hide and Seek in Time - Robust Covert Timing Channels

Abstract. Covert timing channels aim at transmitting hidden messages by controlling the time between transmissions of consecutive payload packets in overt network communication. Previous results used encoding mechanisms that are either easy to detect with statistical analysis, thus spoiling the purpose of a covert channel, and/or are highly sensitive to channel noise, rendering them useless in practice. In this paper, we introduce a novel covert timing channel which allows to balance undetectability and robustness: i) the encoded message is modulated in the inter-packet delay of the underlying overt communication channel such that the statistical properties of regular traffic can be closely approximated and ii) the underlying encoding employs spreading techniques to provide robustness. We experimentally validate the effectiveness of our approach by establishing covert channels over online gaming traffic. The experimental results show that our covert timing channel can achieve strong ...

• Type: Conference
• Year: 2009
• Where: ESORICS
• Authors: Yali Liu, Dipak Ghosal, Frederik Armknecht, Ahmad-Reza Sadeghi, Steffen Schulz, Stefan Katzenbeisser
• Keywords: Covert Channels, Covert Timing Channel, ESORICS 2009, Overt Communication Channel, Security Privacy