Optimal Multiuser Spread-Spectrum Steganography & Steganalysis

Lecture / Panel
For NYU Community

Speaker: Professor Stella Batalama 

Host Faculty: Professor Elza Erkip


For any given digital host (audio, image, video) or group of hosts and any (block) transform domain of interest, we find the signature vector that when used for spread-spectrum (SS) message embedding maximizes the signal-to-interference-plus-noise ratio (SINR) at the output of the corresponding maximum-SINR linear filter. We establish that, under a (colored) Gaussian assumption on the transform domain host data, the same derived signature minimizes host distortion for any target message recovery error rate and maximizes the Shannon capacity of the covert steganographic link. Then, we derive jointly optimal signature and linear processor designs for SS embedding in linearly modified transform domain host data and demonstrate orders of magnitude improvement over current SS steganographic practices. Optimized multisignature/multimessage embedding in the same host data is defined as well where multiple messages (or parts thereof) are hidden with different embedding signatures in the same medium with, potentially, different intended recipients along the chain of command. We will also be reporting on counter-measures to (optimal multi-signature) spread-spectrum steganography. Results will be presented on both active (message extraction) and passive (stego/non-stego classification) steganalysis.

About the Speaker

Stella N. Batalama received the Diploma degree in computer engineering and science (5-year program) from the University of Patras, Greece in 1989 and the Ph.D. degree in electrical engineering from the University of Virginia, Charlottesville, VA, in 1994.

In 1995 she joined the Department of Electrical Engineering, State University of New York at Buffalo, Buffalo, NY, where she is presently a Professor. From July 2009 to June 2011, she served as the Associate Dean for Research of the School of Engineering and Applied Sciences and since 2010, she is serving as the Chair of the Electrical Engineering Department. During the summers of 1997-2002 she was Visiting Faculty in the U.S. Air Force Research Laboratory (AFRL), Rome, NY. From Aug. 2003 to July 2004 she served as the Acting Director of the AFRL Center for Integrated Transmission and Exploitation (CITE), Rome NY.

Her research interests include small-sample-support adaptive filtering and receiver design, cooperative communications, cognitive networks, underwater communications, covert communications, steganography, compressive sampling, adaptive multiuser detection, robust spread-spectrum communications, supervised and unsupervised optimization. Dr. Batalama was an associate editor for the IEEE Communications Letters (2000-2005) and the IEEE Transactions on Communications (2002-2008).