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oai:www.ideals.illinois.edu:2142/30903 2023-07-10 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Kiyavash, Negar Rodrigues, Mavis 2012-05-22T00:14:15Z 2012-05-22T00:14:15Z 2012-05 2012-05-22T00:14:15Z 2012-05 The goal of this thesis is to achieve covert communication, i.e. to covertly relay information using resources that are traditionally unintended for data transmission. In a covert channel, only the sender and receiver are aware of the communication and capable of reading the transmitted message, and any other party would not be aware of the existence of this transmission. The timing channel has been studied as a medium for covert communication in a computer network. It offers the means to communicate a message by relaying information encrypted within the timings formed between consecutive packets. This thesis covers two schemes that utilize the timing channel for covert communication -- to send a message and to trace network flows. The former, is the design of the first spyware circuit that covertly leaks spied information using an efficient encoder and for a network employing the CSMA/CA. This protocol modifies the inter-packet delays of the network flow using an exponential back-off rule. The second scheme does not relay any message but adds a signature called a watermark to enable flow tracing through the network with dependent deletion and substitution errors, and unlike earlier schemes, it is capable of withstanding desynchronization caused by packet drops. We will verify that our schemes are detectable by the receiver, and robust to the noise introduced by the network. In addition to their reliability, they are both difficult to detect and remain invisible to an observer. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2012-04-12T20:50:42Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Rodrigues_Mavis.pdf.pdf: 792968 bytes, checksum: 9b3e344b17256bf518f0587a61bd6cd5 (MD5) Rodrigues_Mavis.pdf: 792968 bytes, checksum: 9b3e344b17256bf518f0587a61bd6cd5 (MD5) Made available in DSpace on 2012-05-22T00:14:15Z (GMT). No. of bitstreams: 2 Rodrigues_Mavis.pdf: 792968 bytes, checksum: 9b3e344b17256bf518f0587a61bd6cd5 (MD5) license.txt: 4065 bytes, checksum: a4cc22d32a94b5308f2a6806d973faec (MD5) http://hdl.handle.net/2142/30903 en Copyright 2012 Mavis Rodrigues covert communication watermarking Carrier Sense Multiple Access (CSMA) timing channel Timing channel codes for covert communication and network flow tracing text Electrical & Computer Eng 1933 Electrical & Computer Engr 1200 University of Illinois at Urbana-Champaign Thesis M.S. MS:Electr & Computer Eng-UIUC 10KS1200MS