nado-ga,
Thanks for posting such an intriguing question. I was vaguely aware
of this field, but your query has prompted a closer look.
As you noted, this is a highly-specialized, very technical field.
However, there are still some good overview sources of information,
and numerous examples of steganographic images and the software used
to encode them.
I've included what I consider to be the best-of-the-best below.
This information should fully meet your needs. However, if you find
you would like to know still more, please don't rate this answer until
you have everything you need. Just post a Request for Clarification,
and I'll be happy to assist you further.
Thanks,
pafalafa-ga
==========
[Good overview of the topic, with images]
http://www.personal.psu.edu/users/j/r/jrf224/sections/Steganography/steganography.htm
Using that simple idea of hiding candy can be applied to hiding data
on the internet. Steganography is the science of hiding information
in other information. For instance... notice anything odd about this
picture?
...The only difference between this image and the one on the Berks
website is that this one contains a file in it named
"fun_and_great.txt". The file contains no interesting information but
it does in turn prove a point. I used a program suite called "Steganos
3 Security Suite" which is sold from their website for $49.95 and
there is a preview available for download.
==========
[about 20 examples are included at this site]
http://www-2.cs.cmu.edu/~dst/DeCSS/Gallery/Stego/
Steganography Wing of the
Gallery of CSS Descramblers
Steganography is the art of hiding a secret message inside another message.
==========
[another good overview]
http://www.directionsmag.com/article.php?article_id=189
GIS & Steganography - Part 1: Hidden Secrets in the Digital Ether
Steganography resurfaced into the public's awareness a few months ago
when USA Today published a sensationalist story (1) claiming that
terrorists were using the Internet to distribute secret messages
hidden in pornographic images. While no actual proof has ever been
uncovered that members of Al Qaeda really did use this method, what
raises hairs among the intelligence community is that they could have,
and that it could be very hard to intercept and decode those messages.
But now the jinni of steganography is out of its bottle and all over
the Internet. It could even be lurking in GIS data.
==========
http://dredeyedick.tripod.com/fractaleye/dcm_stego01.htm
Image, Message, Stego, and Jam
Predicting the Presence of Hidden Messages
"Artifacts in the Main Needle"
david manchester gallery
============
[This one is a bit more technical than most, but not in an
overwhelming way, and it includes good up-to-date discussion and a
number of examples]
http://www.garykessler.net/library/fsc_stego.html
An Overview of Steganography for
the Computer Forensics Examiner
February 2004
Steganography is the art of covered or hidden writing. The purpose of
steganography is covert communication-to hide the existence of a
message from a third party. This paper is intended as a high-level
technical introduction to steganography for those unfamiliar with the
field. It is directed at forensic computer examiners who need a
practical understanding of steganography without delving into the
mathematics, although references are provided to some of the ongoing
research for the person who needs or wants additional detail. Although
this paper provides a historical context for steganography, the
emphasis is on digital applications, focusing on hiding information in
online image or audio files. Examples of software tools that employ
steganography to hide data inside of other files as well as software
to detect such hidden files will also be presented.
==========
[this one's interesting, as it extends the concepts not only to
images, but to sound files as well]
http://faculty.olin.edu/~jcrisman/Teaching/SigSysWeb/Project/Stenographyposter.jpg
==========
[Here's some steganographic software you can try at no cost]
http://steganography.say-it-now.com/
Steganography enables you to use digital data hiding techniques
(steganography) to hide files and messages within other files
(carriers) such as picture or sound files. This allows you to encrypt
sensitive information, while at the same time hiding it in a file that
will not look suspicious, so nobody even knows that there is any
encrypted information.
...Try the free trial version...
==========
[And lastly, some books you may want to consider looking into]
http://www.forensics.nl/books-steganography/
Investigator's Guide to Steganography
Multimedia Security: Steganography and Digital Watermarking Techniques
for Protection of Intellectual Property
Information Hiding - Techniques for Steganography and Digital Watermarking
Disappearing Cryptography, Second Edition - Information Hiding:
Steganography and Watermarking
Digital Watermarking: Principles & Practice
Multimedia Data Hiding
==========
Again, please let me know if there's anything else I can do for you.
pafalafa-ga
search strategy -- Searched Google and Google Images for the terms [
steganalysis OR steganography ] |
Clarification of Answer by
pafalafa-ga
on
16 Mar 2005 04:22 PST
My apologies...your question very clearly asked about steganalysis,
and my initial answer wandered into steganography.
I'm more than happy to rectify that, though, but before providing a
list of resources, let me check with you to make sure I'm on the right
track.
Is this the sort of information you are looking for:
-----
http://www.jjtc.com/ihws98/jjgmu.html
Steganalysis of Images Created Using Current Steganography Software
Abstract. Steganography is the art of passing information in a manner
that the very existence of the message is unknown. The goal of
steganography is to avoid drawing suspicion to the transmission of a
hidden message. If suspicion is raised, then this goal is defeated.
Steganalysis is the art of discovering and rendering useless such
covert messages. In this paper, we identify characteristics in current
steganography software that direct the steganalyst to the existence of
a hidden message and introduce the ground work of a tool for
automatically detecting the existence of hidden messages in images.
-----
The paper strikes me as a good overview, without veering too deeply
into the mathematics behind analysis.
Let me know if that sort of paper meets your needs, and if so, I'll
find some additional resources for you along the same lines.
All the best,
pafalafa-ga
|
Clarification of Answer by
pafalafa-ga
on
16 Mar 2005 18:13 PST
nado-ga,
Thanks for your patience on this.
I've dug a little deeper, and have some good resources for you on
steganalysis. It's not possible to avoid the math all together --
especially if you want anything more than a superficial overview --
but I've kept it to a minimum.
Hope this does the trick,
paf
==========
http://www.jjtc.com/pub/nfjidr99.pdf
An Introduction to
Watermark Recovery from Images
Neil F. Johnson
==========
http://niels.xtdnet.nl/stego/
Defeating Statistical Steganalysis
Recently, there has been rumors about terrorist using steganography to
hide their communication and secret plans. However, it is difficult to
verify these claims. To answer this question, I have created a
detection framework that consists of several elements:
A web crawler that saves JPG images.
Its output is piped into stegdetect, a tool for automatic detection of
steganographic content.
The positive results are distributed to a loosely couple cluster of
workstations with disconcert.
On the clients, stegbreak is used to launch a dictionary attack
against the positive images. A normal stegbreak job runs on a few
hundred clients.
==========
http://vision.ece.ucsb.edu/data_hiding/detection.shtml
Steganalysis: Detection of Hidden Data
The widespread use of steganography inevitably leads to a need to
detect hidden data. Steganalysis is detecting and ultimately
extracting data hidden in an innocuous medium. Our goal is to
establish a solid framework for steganalysis, and design systems to
detect state-of-the-art hiding systems. Additionally, we aim to use
lessons learned in detecting to create hiding systems that can evade
detection.
==========
http://vision.ece.ucsb.edu/publications/view_abstract.cgi?205
Steganalysis of spread spectrum data hiding exploiting cover memory
==========
http://vision.ece.ucsb.edu/data_hiding/steganalysis.html
Even with careful scrutiny it is essentially impossible to see the
effects of the hidden data on the image. However, though we do not see
the 32KB of data hidden in the second image, we can detect the
presence of hidden data in 99.99% of images with less than .024% false
alarms. For messages about 2% of the size of the cover image (as in
the third image, which has 4.8KB of message data), we correctly detect
the presence of hidden data 80% of the time with 20% false alarms. We
have also obtained comparable results using the machine learning
approach.
==========
[Lots of links on this site to more in-depth works]
http://web.njit.edu/~shi/Steganalysis/steg.htm
Research on Steganalysis
Introduction
Our Method
Detailed Test Results
Demo (CorelDraw)
Publications
==========
www.krenn.nl/univ/cry/steg/article.pdf
Chapter 1 Steganography and steganalysis
==========
[there are a number of relevant articles here, of varying degrees of
complexity...you might want to spend a bit of time looking them over,
as they cover various techniques]
http://isis.poly.edu/projects/stego/pubs/
This one in particular provides a good overview of both steganography
and steganalysis...it gets a bit technical in parts, but worth a look,
just the same...
http://isis.poly.edu/projects/stego/pubs/ims04.pdf
Image Steganography: Concepts and Practice
==========
And another one -- again, a bit technical, but not overwhelming --
that gives an in-depth discussion of a particular approach...
http://www.busim.ee.boun.edu.tr/~sankur/SankurFolder/Image_Stego.pdf
Steganalysis Using Image Quality Metrics
I trust this added information will meet your needs. But as always,
just let me know if you'd like anything else.
All the best,
paf
|
