Cloak: A Ten-Fold Way for Reliable Covert Communications

A number of network covert channels have been proposed recently that may have important ramifications for Internet security and privacy. However, they could become ineffective in the presence of adverse network conditions and active network intermediaries, such as active wardens. In this paper, we propose Cloak, a new class of timing channels that are more reliable than existing timing channels. Cloak is fundamentally different from other timing channels in several aspects. First, Cloak encodes a message by a unique distribution of N packets over X TCP flows. The combinatorial nature of the encoding methods increases the channel capacity largely with (N, X). Second, Cloak offers ten different encoding and decoding methods, each of which has a unique tradeoff among several important considerations, such as the channel capacity and the need for packet marking. Third, the packet transmissions modulated by Cloak could be carefully crafted to mimic the normal TCP flows in a typical ...

• Type: Conference
• Year: 2007
• Where: ESORICS
• Authors: Xiapu Luo, Edmond W. W. Chan, Rocky K. C. Chang
• Keywords: Cloak Offers, Cloak’s Basic Idea, ESORICS 2007, Security Privacy, Timing Channels