The Center for Education and Research in Information Assurance and Security (CERIAS)

The Center for Education and Research in
Information Assurance and Security (CERIAS)

Mercan Topkara - Purdue University

Students: Spring 2024, unless noted otherwise, sessions will be virtual on Zoom.

Hiding the Message Behind the Words: Advances in Natural Language Watermarking

Apr 18, 2007

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The Internet has become one of the main sources of knowledge
acquisition, harboring resources such as online newspapers, web
portals for scientific documents, personal blogs, encyclopedias, and
advertisements. It has become a part of our daily life to search and
access this immense amount of online information, and more recently we
have also started to contribute to this pool of information our own
creativity in the form of text, images and video. Unfortunately, it is
still an open question as to how we, as authors, can control the way
that the information we create is distributed or re-used.

Rights management problems are serious for text since it is much easy
for other people to download and manipulate copyrighted text from
Internet and later re-use it free from control. There is a need for a
rights protection system that ``travels with the content''. Digital
watermarking is an information hiding mechanism that embeds the
copyright information in the document. Besides traveling with the
content of the documents, digital watermarks are also imperceptible
(i.e., seamless) to the user, which makes the process of removing them
from the document challenging.

Using linguistic features for information hiding into natural language text is an exciting and new idea. This talk begins with a short survey
of existing technologies in natural language watermarking, and then
focuses on a recently developed natural language watermarking system
that is practical, easy-to-use and provides resilience to attacks through
the use of ambiguity in natural language. The talk is aimed for a general
audience, and will be self-contained covering the necessary background

About the Speaker

Mercan Topkara is a PhD candidate at the Computer Science Department
of Purdue University working with Mikhail J. Atallah and Cristina
Nita-Rotaru. She got her Bachelor of Science degree from Computer
Engineering and Information Science Department of Bilkent University
in 2000. She started her graduate studies at Purdue University in
August 2001. Her PhD thesis is focused on designing, building and
evaluating natural language watermarking systems. Her research
interests are within the areas of digital watermarking, statistical
natural language processing, usable security and machine learning. She
has previously worked as a research intern at AT&T Research Labs, IBM
T. J. Watson Research, and Google Research. More information can be
found at

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